070 Summary

Introduction

We have now reached the end of the course material, but hopefully not the end of your learning to code and to manipulate geospatial data. At the start of the course, we assumed you had never done any programming. Now, if you have been through the material and able to complete most of the exercises, formative assessments and coursework, you should be a competent (or better!) coder. We use this final section just to reiterate to you what you have learned. You will see that it a vast amount! We hope you will use this basis as a foundation to go further with your coding, to enable you to get the computer to do what you want, to test out your ideas, rather than being limited by what is currently available. If you need to learn a new some new languages such as javascript or matlab, you will find them very similar to Python. The same will apply to learning any other coding language: once you have a good grasp of the basics and what you can do in programming, you are in control.

We know that there is often a steep learning curve for people new to coding, but we trust you have been able to deal with that and put the effective learning time in to make best use of the course. We also hope that the support from the course tutors and supporting doctoral students has been effective. We hope that you have found the experience enabling.

Recap

As a brief recap on what you have learned:

Course Basics

001 Using Notebooks

001 Using Notebooks: Use of Jupyter notebooks; code and maskdown cells; use of markdown;

002 Unix

002 Unix: Bash commands in notebooks; bash cells; Unix commands:

cmd	meaning	example use
~	twiddle / tilde - home	cd ~/geog0111
.	dot - current directory	cd .
..	dot dot - one level up directory	cd ..
*	wildcard	ls R*
cd	change directory	cd ~/geog0111
pwd	print working directory	pwd
ls	list	ls README.md
ls -l	long list	ls -l README.md
ls -lh	human-readable long list	ls -lh README.md
chmod	change mode (permissions)	chmod 644 README.md
rm	remove	rm work/n*
755	rwxr-xr-x	chmod 755 bin/*
644	rw-r--r--	chmod 644 README.md

003 Getting help

003 Getting help: How to get and read help document strings; the importance of documentation for methods; some examples of Python, mainly with the type list:

command	purpose
help(m)	print document string for method m
m?	print short document string for method m
list	Python data type for lists
list.append()	append item to list
list.clear()	clear item from list
list.sort	in-line list sort
range(start,stop,step)	list-like generator for integers from start to (but not including) stop in steps of step

004 Accounts

004 Accounts: Storing / resetting and testing NASA Earthdata login.

command	purpose
l = Cylog(sites); test = l.login()	set / run login for list of URLs sites
cy = Cylog(sites,force=True); test = l.login()	reset / run login for list of URLs sites
test_login(True)	test the login by pulling a dataset from the NASA site

005 Packages

005 Packages; import packages using import and from.

command	purpose
import yaml	import the package yaml
from pathlib import Path	import the method/ class Path from the package pathlib

Core Concepts

010 Variables, comments and print

010 Variables, comments and print()

Rules and conventions for symbol names.

command	purpose
#	hash symbol, followed by comments
print()	print function
\n	newline character
\t	tab character
varname = value	set variable varname to value
__doc__, __main__	special method names

Variables start with a lower case character and classes start with capitals

Reserved keywords:

            False      class      finally    is         return
            None       continue   for        lambda     try
            True       def        from       nonlocal   while
            and        del        global     not        with
            as         elif       if         or         yield
            assert     else       import     pass
            break      except     in         raise

011 Data types

011 Data types

core data types	example
int	x = 10
float	x = 10.0
str	x = "hello world"
bool	x = False

and how to convert ('cast') between then, where this is feasible:

cast functions
int()
float()
str()
bool()

Other functions:

command	purpose
type(v)	data type of object v
len(v)	length of object v (e.g. str)

We have learned truth tables to list logical operations:

A	B	A and B
T	T	T
T	F	F
F	T	F
F	F	F

A	B	A or B
T	T	T
T	F	T
F	T	T
F	F	F

A	not A
T	F
F	T

012 String formatting

012 String formatting

item	description
"'"	single quote as a string
'"'	double quote as a string
"\\"	backslash as a string (escaped) in string
''' ... '''	multiple line string
*	string multiplication e.g. "0"*2 -> "00"
+	string addition e.g. "0" + "1" -> "01"
str.format()	insert items in string e.g. "{x}".format(x=1) -> "1"
f"..."	f-string, e.g. x=1, f"{x}" -> `"1"

013 Python string methods

013 String methods

item	description
str.replace(a,b)	replace occurrences of a with b in str
str.strip(a)	strip off any occurrences of a on left or right ends of str (also lstrip,rstrip)
str.split(a)	split str into list, using a as the separator, e.g. "1:2".split(":") -> ["1","2"]
a.join(l)	join the string items in list l into a string with a as the separator, e.g. "x".join(["1","2"]) -> "1x2"
str[start:stop:step]	slice str and return characters start to (but not including) stop skipping step values, e.g. "hello"[1:2] -> e

104 Groups

014 Python groups

symbol	description	example	access example
()	tuple: low level group of items accessed by index. Cannot change once set	(1,2,3)	(1,2)[1] -> [2]
[]	list: group of items accessed by index with range of methods. Can change, sort etc.	[1,2,3]	[1,2][1] -> [2]
{}	dict: dictionary, a group of items accessed by key	{"a" : 1}	{"a" : 1}["a"] -> 1
[[],[]]	hierarchical (multi-dimensional) list
[{},{}]	list of dictionaries
{"a":[],"b":[]}	dictionary of lists

List methods:

method	description	example	result
list.index(i)	find index of value i in list	[9,10,11].index(10)	1
list.extend(l)	in-place extend list with list l	x = [9,10,11]; x.extend([12,13])	x -> [9,10,11,12,13]
list.append(l)	in-place append list with list l	x = [9,10,11]; x.append([12,13])	x -> [9,10,11,[12,13]]
list.sort(l)	in-place sort list	x = [10,9,11]; x.sort()	x -> [9,10,11]

Dictionary methods:

method	description	example	result
a.keys()	keys in dictionary a	d={"a":1,"b":2};d.keys()	['a', 'b']
a.values()	values in dictionary a	d={"a":1,"b":2};d.values()	[1, 2]
a.items()	items (key,value) in dictionary a	d={"a":1,"b":2};d.items()	[('a', 1), ('b', 2)])
dict(zip(a,b))	form a dictionary from keys in list a and items in list b	dict(zip(["a","b"],[1,2]))	{'a': 1, 'b': 2}
a.update(d)	update dictionary a with dictionary d	a={"a":1};d={"b":2};a.update(d)	a -> {'a': 1, 'b': 2}

015 Python control

015_Python_control

Comparison operators:

symbol	meaning
==	is equivalent to
!=	is not equivalent to
>	greater than
>=	greater than or equal to
<	less than
<=	less than or equal to

If ... elif ... else:

    if condition1:
        # do this 1
        doit1()
        ...
    elif condition2:
        # do this 2
        doit2()
        ...
    else:
        # do this 3
        doit3()
        ...

016 for ... in ...

016 for

Command	Comment	Example	Result
for item in list:	loop, setting item to each value in list sequentially	see Example 1
for key,value in list_of_tuples:	loop, setting a,b to each value in list of tuples	See Example 2: list({"a":7,"b":3}.items())	[('a', 7), ('b', 3)]
range(start,stop,step)	index iterator from start to stop in steps of step	list(range(1,6,2))	[1, 3, 5]
enumerate(list)	provide index of list	list(enumerate(['a','b','c']))	[(0, 'a'), (1, 'b'), (2, 'c')]
assert condition	test that condition is True, exit otherwise	assert True
[f(x) for x in alist]	list comprehension, applying f(x) to each item x in alist	[i*i for i in range(3)]	[0, 1, 4]
[af(x) for x in alist if ca(x)]	list comprehension with conditional statement, applying af(x) to each element x in alist if ca(x) is True	[i for i in range(11) if i%2]	[1, 3, 5, 7, 9]
[af(x) if ca(x) else bf(x) for x in alist]	list comprehension with conditional statement, applying af(x) to each element x in alist if ca(x) is True, otherwise applying bf(x)	[i if i%2 else 0 for i in range(4)]	[0, 1, 0, 3]

Example 1:

    for item in [1,2,3]:
        # print item in loop
        print(item)

Result:

    1
    2
    3

Example 2:

    for key,value in {"a":7,"b":3}.items():
        print(f'key is {key}, value is {value}')

Result:

    key is a, value is 7
    key is b, value is 3

017 Functions

017 Functions

Anatomy of a function:

    def my_function(arg1,arg2,...,kw0=...,kw1=...):
      '''
      Document string 
      '''

      # comments

      retval =  ...

      # return
      return retval

Also written as:

    def my_function(*args,**kwargs):

We have also seen lambda functions, used for short functions:

    function_name = lambda args : function_code

018 Python codes

018 Python codes

Command	Comment	Example	Result
!unix_cmd	Run unix command unix_cmd from Jupyter code cell	!geog0111/helloWorld.py	hello world
		!ls -l geog0111/helloWorld.py	-rwxr-xr-x 1 ucfalew ucfa 514 Oct 1 13:10 geog0111/helloWorld.py
%%bash	Turn Jupyter Python code cell into bash cell	%%bash
		chmod 755 geog0111/helloWorld.py
		ls -l geog0111/helloWorld.py	-rwxr-xr-x 1 ucfalew ucfa 514 Oct 1 13:10 geog0111/helloWorld.py
%run script.py	Run Python script script.py from Jupyter code cell	%run geog0111/helloWorld.py	hello world
cat << XX > YY; XX	Put marker XX in bash script and send text up to XX into file YY	cat << EOF > work/file.py
		hello world	cat work/file.py
		EOF	hello world

Form of a Python script:

        #!/usr/bin/env python
        # -*- coding: utf-8 -*-

        '''
        helloWorld

        Purpose:

          function print the string 'hello world'

        '''

        __author__    = "P Lewis"
        __copyright__ = "Copyright 2020 P Lewis"
        __license__   = "GPLv3"
        __email__     = "p.lewis@ucl.ac.uk"

        def helloWorld():
            '''
            function to print the string 'hello world'

            '''
            print('hello world')


        # example calling the function
        def main():
            helloWorld()

        if __name__ == "__main__":
            # execute only if run as a script
            main()

Data basics

020 Files

• 020_Python_files

      from pathlib import Path
  

Common Path methods:

command	unix-equivalent	purpose
Path.cwd()	pwd	Return path object representing the current working directory
Path.home()	~	Return path object representing the home directory
Path.stat()	ls -l*	return info about the path. File size is Path.stat().st_size
Path.chmod()	chmod	change file mode and permissions
Path.glob(pattern)	ls *	Glob the pattern given in the directory that is represented by the path, yielding matching files of any kind
Path.mkdir()	mkdir	to create a new directory at the given path
Path.rename()	mv	Rename a file or directory to the given target
Path.rmdir()	rmdir	Remove the empty directory
Path.unlink()	rm	Remove the file or symbolic link

* Really, Path.stat() equates to the unix command stat, but this contains the information we access using ls -l.

        from urlpath import URL

021 URLs

• 021 URLs

In this section, we have considered URLs in some detail in the same way as we did filenames, and made use of functions from urlpath to access them.

function	purpose
URL.name	filename
URL.parent	parent
URL.parts	parts
URL.as_posix()	return URL as posix string
URL.with_userinfo()	add in username and password
URL.get()	URL get. Returns requests.models.Response
URL.netloc	network location e.g. www.google.com
URL.path	full pathname on server (including filename)

We have seen how to access and download both text and binary files from the web using URL.get(). We have seen how to add username and password information to this, and have used that to access MODIS binary datasets. We know how to save the files that we download.

Functions in modisUtils:

function	purpose
modisFile	get a Path object for a file of the requested MODIS dataset, either from cache, or by downloading
modisURL	get the URL of a MODIS dataset, possibly using a cache for the filename

gdal

Command	Comment
g = gdal.Open(filename)	Open geospatial file filename and return gdal object g (None if file not opened correctly)
g.GetSubDatasets()	Get list of sub-datasets from gdal object g
g.ReadAsArray()	Read dataset from gdal object g into array

022 Pandas

• 022 Pandas pandas:

Command	Comment
pd.read_csv(f)	Read CSV data from file or URL f
pd.read_table(f)	Read table data from file or URL f
skiprows=N	Keyword to skip N rows in reading for pd.read_table
na_values=[-99.9]	Keyword to set list of values to ignore (-99.9 here)
sep	Keyword to define field separator
engine='python' or engine='C'	Keyword to set reading engine. python is more flexible, but C is faster.
df.transpose()	Transpose (rows->columns, columns->rows) pandas dataframe df
df.head(N)	first N lines of data (default 5)
df.columns	list-like object of column headings
df[cname]	Select column with name cname
df[[c1,c2,c3]]	Select columns with names c1, c2 and c3
pd.DataFrame(list,columns=cnames)	Create pandas dataframe from information in list-like structures list with names from list cnames
pd.to_datetime(str_list)	convert list of date strings (e.g. of form YYYY-MM-DD) to datetime representation
df[datetimes].dt.month	month from datetime field fromn datetime-format column with name datetimes
df[datetimes].dt.year	year from datetime field fromn datetime-format column with name datetimes
df[datetimes].dt.day	day from datetime field fromn datetime-format column with name datetimes
df.to_csv(filename,index=False)	Write dataframe df to CSV format file, with no index column

023 Plotting Graphs

• 023 Plotting

      import matplotlib.pyplot as plt
      import matplotlib.dates as mdates
  

Function	Comment	Keywords
fig, axs = plt.subplots(xshape,yshape)	set up new figure as array of sub-plots xshape by yshape and return fig object for figure and axs object for subplots. axs is array of objects shape (xshape,yshape), or single object if (1,1). We often use axs = axs.flatten() to flatten the axs array to 1D.	figsize=(sx,sy) : set figure size sx by sy
plt.savefig("ofile.png")	Save plot to file "ofile.png"
fig.suptitle(name)	set title name at top of figure fig
im = axs.plot(xdata,ydata,cs)	plot line graph with ydata as a function of xdata and return plot object im. If argument cs is given, this is a colour/symbol e.g. k+ for black crosses.	label=str : set str as label for this line. For use with legend
im = plt.errorbar(xdata,ydata)	Error bar plot for ydata as a function of xdata. Needs kwarg	yerr=yerr : set y-error bar to values in array yerr
axs.set_xlim(x0,x1)	Set plot x-extent to from x0 to x1
axs.set_ylim(y0,y1)	Set plot x-extent to from y0 to y1
axs.set_title(name)	set sub-plot axs title to name
axs.set_xlabel(xlab)	set x-axis label to xlab
axs.set_ylabel(ylab)	set y-axis label to ylab	1
axs.legend()	set legend in plot	loc='best' : best location, otherwise top left etc.
mdates.MonthLocator()	MonthLocator object of month locators, e.g. months = mdates.MonthLocator()
axs.xaxis.set_major_locator(months)	set major ticks on x-axis to Locator object of months

Some colours and symbols:

symbol/colour	name
'k+'	black plus
'r.'	red dot
'go'	green circle
'b-'	blue line
'c--'	cyan dashed line
'y-o'	yellow line with circles

datetime

        from datetime import datetime

function	comment
datetime.now()	date and time for now
datetime(year, month, day, hour, minute, second, millisecond)	return datatime object for time/date specified. Not all fields need be given. Can also use keywords but year, month and day must be given e.g.: datetime(2020,day=1,month=2,hour=12)
datetime.day	day etc.
timedelta	subtract two datetimes to get a timedelta
timedelta.days	number of days in timedelta
dt.strftime("%H:%M:%S")	represent datetime object dt as hour:minute:second
dt.strftime("%m/%d/%Y")	represent datetime object dt as month/day/year
datetime.strptime(str,format)	load string str into datetime object interpreting as format format, e.g. datetime.strptime("11 November, 1918", "%d %B, %Y") -> 1918-11-11 00:00:00; e.g. datetime.strptime("2020-06-20", "%Y-%m-%d") -> 2020-06-20 00:00:00

Image Display

• 024_Image_display

      import matplotlib
      import matplotlib.pyplot as plt
  

function	comment	keywords
im = axs.imshow(data2D)	Display image of 2D data array data2D on sub-plot axis axs and return display object im	vmin= : minimum threshold for image display
		vmax= : maximum threshold for image display
		interpolation= : interpolation style (e.g. 'nearest'
fig.colorbar(im)	Set colour bar for image plot object im	ax=axs plot on sub-plot axs
im.set_cmap(c)	set colourmap c for image object im
	Examples being ['Greys','gray','inferno_r','seismic']
cmap = matplotlib.colors.ListedColormap(list_of_colours)	set cmap to Colormap object from list of colours list_of_colours
norm = matplotlib.colors.BoundaryNorm(list, nbound)	set BoundaryNorm object norm to boundaries of values from list with nbound values
matplotlib.patches.Patch(color=c, label=l)	Set patches for legend with colours from list c and labedl from list l
plt.legend(handles=patches)	set figure legend using patches	bbox_to_anchor=(1.4, 1) : shift of legend
		facecolor="white" : facecolourt of legend (white here)

Array data

030 NASA MODIS Earthdata

030_NASA_MODIS_Earthdata

NASA Earthdata

Some MODIS datasets

• MCD15A3H LAI/fAPAR
• MCD64A1 Burned Area1
• MOD10A1 / MYD10A1 Snow Products
• Land Cover dataset MCD12Q1

031 Manipulating data: numpy

031_Numpy

        import numpy as np

Function	description	keywords
np.array(x)	convert x (e.g. list) to numpy array	dtype= : specify data type, e.g. np.float, np.bool, np.int
np.ones(s)	generate array of values 1 of shape s	dtype=
np.zeros(s)	generate array of values 0 of shape s	dtype=
np.linspace(start,stop,nsamp)	generate array of nsamp values from start to stop	dtype=
np.arange(start,stop,step)	generate array of numbers from start to (but not including) stop in steps of step	dtype=
p0,p1 = np.mgrid[p0min:p0max:p0step,p1min:p1max:p1step]	generate grids p0, p1 of combinations of samples from p0min to (but not including) p0max in steps of p0step and p1min to (but not including) p1max in steps of p1step
a.astype(dtype)	convert array a to data type dtype
a * b	multiply array a element-wise by array b , etc. for arithmetic
a.shape	tuple giving shape of array a
a.ndim	tuple giving number of dimensions of array a
a.size	tuple giving total number of elements in array a
a[start:stop:step]	array indexing for slice from start to stop in steps of step e.g. np.array([2,5,3])[2:3])
a[index]	array indexing by explicit index tuple or tuple list e.g. np.array([2,5,3])[(1,)]
a.min()	minimum value in array a	axis=N : value taken over axis N
a.max()	maximum value in array a	axis=N : value taken over axis N
a.mean()	mean value in array a	axis=N : value taken over axis N
a.std()	standard deviation of values in array a	axis=N : value taken over axis N
a.var()	variance of values in array a	axis=N : value taken over axis N
a.sum()	sum of values in array a	axis=N : value taken over axis N
a.prod()	product of values in array a	axis=N : value taken over axis N
np.median(a)	median of values in array a, assumed a values in radians	axis=N : value taken over axis N
np.sqrt(a)	square root of values in array a
np.sin(a)	sine of values in array a, assumed a values in radians etc.
np.exp(a)	exponential of values in array a

031 More numpy

032_More_numpy

Function	description	keywords
np.loadtxt(f)	Load datra from file f into numpy array
x[start:stop:step]	1-D slice of array x
slice(start:stop:step)	function to apply to slice e.g. x[slice(start:stop:step)]
np.argmin(x)	return 1D index of minimum value in array (/axis)	axis=N : value taken over axis N
np.argmax(x)	return 1D index of maximum value in array (/axis)	axis=N : value taken over axis N
x > 1	logical operator resulting in boolean array e.g. to use for masks
np.logical_not(x)	element-wise not over array
np.logical_or(x,y)	element-wise a or b over array
np.logical_and(x,y)	element-wise a and b over array
np.where(x)	list of indices where x is True
x.flatten()	convert copy of ND array x into 1D array
x.ravel()	convert ND array x into 1D array
x.reshape(shape)	apply shape shape to array x
np.unravel_index(indices,shape)	unravel 1D indices indices to ND defined by shape
np.newaxis	add a new axis to array for reconciling multiple dimensions making a copy. Effectively makes new dimension of size (1,)

Geospatial data

040 GDAL: mosaicing and masking

040_GDAL_mosaicing_and_masking

MODIS utils

from geog0111.modisUtils import modisHTML
help(modisHTML)

Help on function modisHTML in module geog0111.modisUtils:

modisHTML(year=2020, month=1, day=1, tile='h08v06', product='MCD15A3H', timeout=None, version='006', no_cache=False, cache=None, verbose=False, force=False, altcache='/tmp/.modis_cache')
    Example of use:

      from geog0111.modisUtils import modisHTML

      modinfo = {
        'product'  : 'MCD15A3H',
        'year'     : 2020,
        'month'    : 1,
        'day'      : 5,
        'tile'     : 'h08v06'
      }

      html,html_file = modisHTML(**modinfo,verbose=False)

    Returns:
      html  : string of html from MODIS data product page
              e.g. what you would find on 
              https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05
      html_file : local file dump

    Control options:
      year : int of year (2000+ for Terra, 2002+ for Aqua products)
             (year=2020)
      month: int of month (1-12) (month=1)
      day  : int of day (1-31, as appropriate) (day=1)
      tile : string of tile (tile='h08v06')  
      product : string of MODIS product name (product='MCD15A3H')
      version : int or string of version (version='006')
      timeout : timeout in seconds

      verbose : verbosity (verbose=False)


    Cache options:
      no_cache : Set True if you don't want to use the cache 
                 (no_cache=False)

                 This is common for most functions, but 
                 modisFile() will use a cache in any case, 
                 as it has to store the file somewhere. 
                 If you don;'t want to keep that, then 
                 you can delete after use.
      cache    : Use cache='/home/somewhere/else' to specify 
                 a personal cache location with write permission 
                 (ie somewhere in your filespace)
                 Specify personal cache root. By default, 
                 this will be ~, and the cache will go into 
                 ~/.modis_cache. You can change that to 
                 somewhere else
                 here. It will still use the sub-directory 
                 .modis_cache.
                 Use cache='/home/somewhere/else' to specify a 
                 personal cache location with write permission 
                 (ie somewhere in your filespace)
      altcache : Specify system cache root. 
                 Use altcache='/home/notme/somewhere' to specify a 
                 system cache location with read permission 
                 (ie somewhere not necessarily in your filespace)
      force    : Bool : Use force=True to override information in the cache


    Get the HTML associated with a MODIS product
    for a certain date and version. Since this can
    be an expensive call, the html can be cached unless no_cache = True

    This function returns the HTML for the product/date page listing

    You can use this to discover data file names/URLs by parsing
    the html.

    The caching is done to avoid repeated calls to expensive URL downloads.
    The idea is that there will be a system cache, where shared files will
    be set up (where you have read permission), and a personal cache
    where you can read and write your own files. Unless you
    use force=True or disble cache with no_cache=True, then the code
    will look in (i) personal; (ii) system cache before attempting
    to download any file from a URL.

    The cached files are stored in the same structure as the URL, i.e

    https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    will be stored (personal cache) as:

    ~/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    The html cache is what is returned from e.g.

    https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05

    and is stored as eg

    ~/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/index.html

from geog0111.modisUtils import modisServer
help(modisServer)

Help on function modisServer in module geog0111.modisUtils:

modisServer(product='MCD15A3H', version='006', **kwargs)
    modisServer : return the server and dirbase for
                  a given product.

    e.g. modisServer('MCD15A3H') ->  https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006

    Example of use:

      from geog0111.modisUtils import modisServer

      modinfo = {
        'product'  : 'MCD15A3H',
        'year'     : 2020,
        'month'    : 1,
        'day'      : 5,
        'tile'     : 'h08v06'
      }

      server = modisServer(**modinfo,verbose=False)
      print(f'-> {server}')
      -> https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006

    Returns:
      server   : URL of core MODIS data product page
                 e.g. https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006

    Control options:
      tile : string of tile (tile='h08v06')  
      product : string of MODIS product name (product='MCD15A3H')

    Note that other kwargs are allowed (for compatibility) but ignored.

from geog0111.modisUtils import modisURL
help(modisURL)

Help on function modisURL in module geog0111.modisUtils:

modisURL(year=2020, month=1, day=1, tile='h08v06', product='MCD15A3H', version='006', timeout=None, no_cache=False, cache=None, verbose=False, force=False, altcache='/tmp/.modis_cache')
    modisURL : return the URL for a MODIS product
               E.g.
               https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    Example of use:

      from geog0111.modisUtils import modisURL

      modinfo = {
        'product'  : 'MCD15A3H',
        'year'     : 2020,
        'month'    : 1,
        'day'      : 5,
        'tile'     : 'h08v06'
      }

      url = modisURL(**modinfo,verbose=False)
      print(f'-> {url}')
      -> https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf
    Returns:
      url  : Url (urlpath URL object) of MODIS data product
              e.g. https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    Control options:
      year : int of year (2000+ for Terra, 2002+ for Aqua products)
             (year=2020)
      month: int of month (1-12) (month=1)
      day  : int of day (1-31, as appropriate) (day=1)
      tile : string of tile (tile='h08v06')  
      product : string of MODIS product name (product='MCD15A3H')
      version : int or string of version (version='006')
      timeout : timeout in seconds

      verbose : verbosity (verbose=False)

    Cache options:
      no_cache : Set True if you don't want to use the cache 
                 (no_cache=False)

                 This is common for most functions, but 
                 modisFile() will use a cache in any case, 
                 as it has to store the file somewhere. 
                 If you don;'t want to keep that, then 
                 you can delete after use.
      cache    : Use cache='/home/somewhere/else' to specify 
                 a personal cache location with write permission 
                 (ie somewhere in your filespace)
                 Specify personal cache root. By default, 
                 this will be ~, and the cache will go into 
                 ~/.modis_cache. You can change that to 
                 somewhere else
                 here. It will still use the sub-directory 
                 .modis_cache.
                 Use cache='/home/somewhere/else' to specify a 
                 personal cache location with write permission 
                 (ie somewhere in your filespace)
      altcache : Specify system cache root. 
                 Use altcache='/home/notme/somewhere' to specify a 
                 system cache location with read permission 
                 (ie somewhere not necessarily in your filespace)
      force    : Bool : Use force=True to override information in the cache

    Get the URL associated with a MODIS product
    for a certain date and version. Since this can
    involve  an expensive call to get the html to access the file URL
    The html data used can be cached unless no_cache = True
    (See modisHTML())

    This function returns the URL for the product/date page listing

    The caching is done to avoid repeated calls to expensive URL downloads.
    The idea is that there will be a system cache, where shared files will
    be set up (where you have read permission), and a personal cache
    where you can read and write your own files. Unless you
    use force=True or disble cache with no_cache=True, then the code
    will look in (i) personal; (ii) system cache before attempting
    to download any file from a URL.

    The cached files are stored in the same structure as the URL, i.e

    https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    will be stored (personal cache) as:

    ~/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    The html cache is what is returned from e.g.

    https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05

    and is stored as eg

    ~/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/index.html

from geog0111.modisUtils import modisFile
help(modisFile)

Help on function modisFile in module geog0111.modisUtils:

modisFile(year=2020, month=1, day=1, tile='h08v06', product='MCD15A3H', timeout=None, version='006', no_cache=False, cache=None, verbose=False, force=False, altcache='/tmp/.modis_cache')
    Get the filename associated with a MODIS product file
    for a certain date and version.

    modisFile : return the filename for a MODIS product
               E.g.
               /Users/plewis/.modis_cache/e4ftl01.cr.usgs.gov/                    MOTA/MCD15A3H.006/2020.01.05/                    MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    N.B. You need to have a username and password to access the data.
    These are available at https://urs.earthdata.nasa.gov

    Example of use:

      from geog0111.modisUtils import modisURL, modisFile

      modinfo = {
        'product'  : 'MCD15A3H',
        'year'     : 2020,
        'month'    : 1,
        'day'      : 5,
        'tile'     : 'h08v06'
      }

      url = modisURL(**modinfo,verbose=False)
      print(f'-> {url}')

      filename = modisFile(**modinfo,verbose=False)
      print(f'-> {filename}')

      -> https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

      -> /Users/plewis/.modis_cache/e4ftl01.cr.usgs.gov/           MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf


    Returns:
      filename  : Path object of MODIS data product file
              e.g. what you would find on

              https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

              Downloaded to some cache location e.g.

              /Users/plewis/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    Control options:
      year : int of year (2000+ for Terra, 2002+ for Aqua products)
             (year=2020)
      month: int of month (1-12) (month=1)
      day  : int of day (1-31, as appropriate) (day=1)
      tile : string of tile (tile='h08v06')  
      product : string of MODIS product name (product='MCD15A3H')
      version : int or string of version (version='006')
      timeout : timeout in seconds

      verbose : verbosity (verbose=False)


    Cache options:
      no_cache : Set True if you don't want to use the cache 
                 (no_cache=False)

                 This is common for most functions, but 
                 modisFile() will use a cache in any case, 
                 as it has to store the file somewhere. 
                 If you don;'t want to keep that, then 
                 you can delete after use.
      cache    : Use cache='/home/somewhere/else' to specify 
                 a personal cache location with write permission 
                 (ie somewhere in your filespace)
                 Specify personal cache root. By default, 
                 this will be ~, and the cache will go into 
                 ~/.modis_cache. You can change that to 
                 somewhere else
                 here. It will still use the sub-directory 
                 .modis_cache.
                 Use cache='/home/somewhere/else' to specify a 
                 personal cache location with write permission 
                 (ie somewhere in your filespace)
      altcache : Specify system cache root. 
                 Use altcache='/home/notme/somewhere' to specify a 
                 system cache location with read permission 
                 (ie somewhere not necessarily in your filespace)
      force    : Bool : Use force=True to override information in the cache

    Get the URL associated with a MODIS product
    for a certain date and version. Since this can
    involve  an expensive call to get the html to access the file URL
    The html data used can be cached unless no_cache = True
    (See modisHTML())

    This function returns the URL for the product/date page listing

    The caching is done to avoid repeated calls to expensive URL downloads.
    The idea is that there will be a system cache, where shared files will
    be set up (where you have read permission), and a personal cache
    where you can read and write your own files. Unless you
    use force=True or disble cache with no_cache=True, then the code
    will look in (i) personal; (ii) system cache before attempting
    to download any file from a URL.

    The cached files are stored in the same structure as the URL, i.e

    https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/                MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    will be stored (personal cache) as:

    ~/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/                MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    The html cache is what is returned from e.g.

    https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05

    and is stored as eg

    ~/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/index.html

from geog0111.modisUtils import getModisFiles
help(getModisFiles)

Help on function getModisFiles in module geog0111.modisUtils:

getModisFiles(doys=None, year=2020, tile='h08v06', doy=None, month=None, product='MCD15A3H', timeout=None, sds='None', version='006', no_cache=False, cache=None, verbose=False, force=False, altcache='/tmp/.modis_cache')
    return list of MODIS data filenames of given SDS for given MODIS tile

    N.B. You need to have a username and password to access the data.
    These are available at https://urs.earthdata.nasa.gov

    Example of use:

      from geog0111.modisUtils import getModisFiles

      modinfo = {
        'product'  : 'MCD15A3H',
        'year'     : 2020,
        'doys'     : [1,5]
        'tile'     : 'h08v06'
      }

      data = getModisFiles(**modinfo,verbose=False)
      print(f'-> {*data.keys()}')

      -> Fpar_500m Lai_500m FparLai_QC FparExtra_QC FparStdDev_500m LaiStdDev_500m


    Returns file list of MODIS data product filef
              e.g. what you would find on

           https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

              Downloaded to some cache location e.g.

              /Users/plewis/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    Control options:
      year : int of year (2000+ for Terra, 2002+ for Aqua products)
             (year=2020)

      doy  : day of year (doy=None)
      OR
      month: int of month (1-12) (month=1)
      day  : int of day (1-31, as appropriate) (day=1)

      tile    : string of tile (tile='h08v06')  
      product : string of MODIS product name (product='MCD15A3H')
      version : int or string of version (version='006')
      sds     : only load these SDS (string or list)

      timeout : timeout in seconds
      verbose : verbosity (verbose=False)


    Cache options:
      no_cache : Set True if you don't want to use the cache 
                 (no_cache=False)

                 This is common for most functions, but 
                 modisFile() will use a cache in any case, 
                 as it has to store the file somewhere. 
                 If you don;'t want to keep that, then 
                 you can delete after use.
      cache    : Use cache='/home/somewhere/else' to specify 
                 a personal cache location with write permission 
                 (ie somewhere in your filespace)
                 Specify personal cache root. By default, 
                 this will be ~, and the cache will go into 
                 ~/.modis_cache. You can change that to 
                 somewhere else
                 here. It will still use the sub-directory 
                 .modis_cache.
                 Use cache='/home/somewhere/else' to specify a 
                 personal cache location with write permission 
                 (ie somewhere in your filespace)
      altcache : Specify system cache root. 
                 Use altcache='/home/notme/somewhere' to specify a 
                 system cache location with read permission 
                 (ie somewhere not necessarily in your filespace)
      force    : Bool : Use force=True to override information in the cache

    Get the URL associated with a MODIS product
    for a certain date and version. Since this can
    involve  an expensive call to get the html to access the file URL
    The html data used can be cached unless no_cache = True
    (See modisHTML())

    This function returns the URL for the product/date page listing

    The caching is done to avoid repeated calls to expensive URL downloads.
    The idea is that there will be a system cache, where shared files will
    be set up (where you have read permission), and a personal cache
    where you can read and write your own files. Unless you
    use force=True or disble cache with no_cache=True, then the code
    will look in (i) personal; (ii) system cache before attempting
    to download any file from a URL.

    The cached files are stored in the same structure as the URL, i.e

    https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    will be stored (personal cache) as:

    ~/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    The html cache is what is returned from e.g.

    https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05

    and is stored as eg

    ~/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/index.html

from geog0111.modisUtils import getModisTiledata
help(getModisTiledata)

Help on function getModisTiledata in module geog0111.modisUtils:

getModisTiledata(doy=None, year=2020, month=1, day=1, tile='h08v06', product='MCD15A3H', timeout=None, sds='None', version='006', no_cache=False, cache=None, verbose=False, force=False, altcache='/tmp/.modis_cache')
    return MODIS data dictionary of given SDS for given MODIS tile

    N.B. You need to have a username and password to access the data.
    These are available at https://urs.earthdata.nasa.gov

    Example of use:

      from geog0111.modisUtils import getModisdata

      modinfo = {
        'product'  : 'MCD15A3H',
        'year'     : 2020,
        'month'    : 1,
        'day'      : 5,
        'tile'     : 'h08v06'
      }

      data = getModisdata(**modinfo,verbose=False)
      print(f'-> {*data.keys()}')

      -> Fpar_500m Lai_500m FparLai_QC FparExtra_QC FparStdDev_500m LaiStdDev_500m


    Returns data read from MODIS data product file
              e.g. what you would find on

           https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

              Downloaded to some cache location e.g.

              /Users/plewis/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    Control options:
      year : int of year (2000+ for Terra, 2002+ for Aqua products)
             (year=2020)

      doy  : day of year (doy=None)
      OR
      month: int of month (1-12) (month=1)
      day  : int of day (1-31, as appropriate) (day=1)

      tile    : string of tile (tile='h08v06')  
      product : string of MODIS product name (product='MCD15A3H')
      version : int or string of version (version='006')
      sds     : only load these SDS (string or list)

      timeout : timeout in seconds
      verbose : verbosity (verbose=False)


    Cache options:
      no_cache : Set True if you don't want to use the cache 
                 (no_cache=False)

                 This is common for most functions, but 
                 modisFile() will use a cache in any case, 
                 as it has to store the file somewhere. 
                 If you don;'t want to keep that, then 
                 you can delete after use.
      cache    : Use cache='/home/somewhere/else' to specify 
                 a personal cache location with write permission 
                 (ie somewhere in your filespace)
                 Specify personal cache root. By default, 
                 this will be ~, and the cache will go into 
                 ~/.modis_cache. You can change that to 
                 somewhere else
                 here. It will still use the sub-directory 
                 .modis_cache.
                 Use cache='/home/somewhere/else' to specify a 
                 personal cache location with write permission 
                 (ie somewhere in your filespace)
      altcache : Specify system cache root. 
                 Use altcache='/home/notme/somewhere' to specify a 
                 system cache location with read permission 
                 (ie somewhere not necessarily in your filespace)
      force    : Bool : Use force=True to override information in the cache

    Get the URL associated with a MODIS product
    for a certain date and version. Since this can
    involve  an expensive call to get the html to access the file URL
    The html data used can be cached unless no_cache = True
    (See modisHTML())

    This function returns the URL for the product/date page listing

    The caching is done to avoid repeated calls to expensive URL downloads.
    The idea is that there will be a system cache, where shared files will
    be set up (where you have read permission), and a personal cache
    where you can read and write your own files. Unless you
    use force=True or disble cache with no_cache=True, then the code
    will look in (i) personal; (ii) system cache before attempting
    to download any file from a URL.

    The cached files are stored in the same structure as the URL, i.e

    https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    will be stored (personal cache) as:

    ~/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/MCD15A3H.A2020005.h08v06.006.2020010210940.hdf

    The html cache is what is returned from e.g.

    https://e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05

    and is stored as eg

    ~/.modis_cache/e4ftl01.cr.usgs.gov/MOTA/MCD15A3H.006/2020.01.05/index.html

from geog0111.modisUtils import stitchModisDate
help(stitchModisDate)

Help on function stitchModisDate in module geog0111.modisUtils:

stitchModisDate(year=2019, doy=1, sds='Lai_500m', timeout=None, tile=['h17v03', 'h18v03'], verbose=False, product='MCD15A3H')
    function called stitchModisDate with arguments:

    year
    doy

    keywords/defaults:

        sds      : 'Lai_500m'
        tile     : ['h17v03','h18v03']
        product  : 'MCD15A3H'

    generates a stitched VRT file with the appropriate data,

    returns VRT filename for this dataset.

    Options:
    timeout : None
    verbose : False

from geog0111.modisUtils import modisAnnual
help(modisAnnual)

Help on function modisAnnual in module geog0111.modisUtils:

modisAnnual(ofile_root='work/output_filename', **kwargs)
     generate dictionary of SDS datasets as VRT files

    arguments based on:

     warp_args = {
         'dstNodata'     : 255,
         'format'        : 'MEM',
         'cropToCutline' : True,
         'cutlineWhere'  : "FIPS='LU'",
         'cutlineDSName' : 'data/TM_WORLD_BORDERS-0.3.shp'
     }

     kwargs = {
         'tile'      :    ['h18v03','h18v04'],
         'product'   :    'MCD15A3H',
         'sds'       :    ['Lai_500m', 'Fpar_500m'],
         'doys'      : [i for i in range(1,60,4)],
         'year'      : 2019,
         'warp_args' : warp_args
     }

     Return odict,bnames

     where odict keys are SDS values and the values VRT filenames

gdal:

function	comment	example and keywords
g = gdal.Open(filename)	Open geospatial file filename and return gdal object g (None if file not opened correctly)
g.GetSubDatasets()	Get list of sub-datasets from gdal object g
g.ReadAsArray(c0,r0,nc,nr)	Read dataset from gdal object g into array. Form c0 for nc columns and r0 for nr rows. Set as None for defaults or don't give.
gdal.BuildVRT(ofile, sds)	create gdal VRT (wrapper) file called ofile for SDS/file sds	files,sds = modis.get_files(year,doy)
		separate=True for separate bands
		ofile = f"work/stitch_full_{year}_{doy:03d}.vrt"
		stitch_vrt = gdal.BuildVRT(ofile, sds[0])
gdal.Info(f)	Print information about geospatial file f
gdal.Warp(ofile,ifile)	Warp ifile to ofile with keyword parameters	Keywords:
		format = 'MEM' or format = 'GTiff' : output format
		options=['COMPRESS=LZW'] : compression option for GTiff etc.
		dstNodata=255: no data value
		cropToCutline = True : whether to crop to cutline or bounds
		cutlineDSName = 'data/TM_WORLD_BORDERS-0.3.shp' : vector dataset for cutline
		cutlineWhere = "FIPS='UK'" : identifier information for cutline
g.FlushCache()	flush open gdal object g (force write to file)

041 GDAL: mosaicing and masking

041_GDAL timeseries

from geog0111.modisUtils import getLai
help(getLai)

Help on function getLai in module geog0111.modisUtils:

getLai(year=2019, tile=['h18v03', 'h18v04'], country='LU')
    Get LAI and std for year,tile,country

043 Weighted interpolation

043_Weighted_interpolation

function	comment
scipy.ndimage.filters	scipy filters
zscipy.ndimage.filters.convolve1d(data,filter)	1D convolution of filter with data. Keywords : axis=0,mode='wrap'

from geog0111.modisUtils import regularise
help(regularise)

Help on function regularise in module geog0111.modisUtils:

regularise(lai, weight, sigma)
    takes as argument:

        lai     : MODIS LAI dataset:     shape (Nt,Nx,Ny)
        weight  : MODIS LAI weight:      shape (Nt,Nx,Ny)
        sigma   : Gaussian filter width: float

    returns an array the same shape as 
    lai of regularised LAI. Regularisation takes place along
    axis 0 (the time axis)

---

Last update: December 6, 2022