Unit 29 - PyWPS LST region statsΒΆ
A third version of the process will return LST statistics for region
in Germany defined by input vector (polygon) data. Input area of
interest is defined as region ComplexInput parameter
(9,18-21) and imported by v.import (line
53), resultant statistics is computed similarly as in process
verion 1 (Unit 27 - PyWPS intro) by t.rast.series (line 59)
and r.univar (line 72). Before computation the
computational region and mask is set by g.region
(56) and r.mask (57). Statistics is
provided in JSON structure similary to process version 2 (Unit 28 - PyWPS LST point stats)
on line 83.
Note that also class name (30), process identifier (32), title (33), abstract (38) and version (39) needs to be updated.
#!/usr/bin/env python3
import json
from subprocess import PIPE
from datetime import datetime
from grass.pygrass.modules import Module
from grass.script import parse_key_val
from pywps import Process, LiteralInput, ComplexInput, ComplexOutput, Format
class ModisV3(Process):
def __init__(self):
inputs = list()
outputs = list()
inputs.append(ComplexInput('region', 'Input vector region',
supported_formats=[
Format('text/xml'),
Format('application/gml+xml')]))
inputs.append(LiteralInput('start', 'Start date (eg. 2023-03-01)',
data_type='string'))
inputs.append(LiteralInput('end', 'End date (eg. 2023-03-01)',
data_type='string'))
outputs.append(ComplexOutput('output', 'Computed LST statistics',
supported_formats=[Format('application/json')]))
super(ModisV3, self).__init__(
self._handler,
identifier="modis-v3",
title="Modis process (v3)",
inputs=inputs,
outputs=outputs,
# here you could also specify the GRASS location, for example:
# grass_location="EPSG:5514",
abstract="Computes LST stats for given area and period (limited to Germany and 2023).",
version="0.3",
store_supported=True,
status_supported=True)
@staticmethod
def _handler(request, response):
def check_date(date_str):
d = datetime.strptime(date_str, '%Y-%m-%d')
if d.year != 2023:
raise Exception("Only year 2023 allowed")
check_date(request.inputs['start'][0].data)
check_date(request.inputs['end'][0].data)
Module('v.import',
input=request.inputs['region'][0].file,
output='poly', overwrite=True)
Module('g.region', vector='poly', align='c_001')
Module('r.mask', vector='poly', overwrite=True)
Module("t.rast.series",
overwrite=True,
input="modis_c@PERMANENT",
method="average",
order="start_time",
nprocs=1,
memory=300,
where="start_time >= '{}' and start_time < '{}'".format(
request.inputs["start"][0].data,
request.inputs["end"][0].data),
output="t_rast_series_out",
file_limit=1000)
m = Module("r.univar",
flags="g",
overwrite=True,
map="t_rast_series_out",
percentile=90,
nprocs=1,
separator="pipe",
stdout_=PIPE)
stats = parse_key_val(m.outputs.stdout, val_type=float)
response.outputs['output'].data = json.dumps(stats)
return response
if __name__ == "__main__":
from pywps.app.Service import Service
processes = [ModisV3()]
application = Service(processes)
Sample process to download: modis_v3.py
Important
Do not forget to import process as done in Unit 27 and restart demo PyWPS server.
Copy jena_boundary.gpkg to pywps-flask-master/static/data and
execute the process.
Possible response.
<wps:ComplexData mimeType="application/json" encoding="" schema="">
{"n": 115.0, "null_cells": 109.0, "cells": 224.0, "min": 1.02076923076927,...}
</wps:ComplexData>