Hi shouvik jha ,
Just to give an example of how you could combine the Neil Ayres suggestion with the snippet Dan Patterson posted earlier, using two raster from the data you attached earlier (2010 r001_NPP vs r005_NPP):
def main():
import arcpy
import os
import math
from matplotlib import pyplot as plt
ras1 = r'D:\Xander\GeoNet\MeanRasters\data\r001_NPP.TIF'
ras2 = r'D:\Xander\GeoNet\MeanRasters\data\r005_NPP.TIF'
fc_pnt = r'D:\Xander\GeoNet\MeanRasters\gdb\data.gdb\randompoints'
num_points = 1000
# minimum distance between points to avoid points in same pixel
min_dist = math.hypot(arcpy.Describe(ras1).meanCellHeight, arcpy.Describe(ras1).meanCellWidth)
# Create random points
ws, fc_name = os.path.split(fc_pnt)
arcpy.CreateRandomPoints_management(out_path=ws, out_name=fc_name,
constraining_extent=ras1,
number_of_points_or_field=num_points,
minimum_allowed_distance=min_dist)
# Extract Multi Values to Points
arcpy.CheckOutExtension("Spatial")
ws, ras1_name = os.path.split(ras1)
ws, ras2_name = os.path.split(ras2)
ras1_name = ras1_name.replace('.', '_')
ras2_name = ras2_name.replace('.', '_')
in_rasters = [[ras1, ras1_name], [ras2, ras2_name]]
arcpy.sa.ExtractMultiValuesToPoints(fc_pnt, in_rasters, "NONE")
arcpy.CheckInExtension("Spatial")
# create lists of values
xs = [r[0] for r in arcpy.da.SearchCursor(fc_pnt, (ras1_name)) if not r[0] is None]
ys = [r[0] for r in arcpy.da.SearchCursor(fc_pnt, (ras2_name)) if not r[0] is None]
# create plot
plt.scatter(xs, ys)
main_title ="Scatter plot of {0} vs {1}".format(ras1_name, ras2_name)
plt.title(main_title, loc='center')
plt.minorticks_on()
plt.show()
if __name__ == '__main__':
main()
Which yields this:
Below the point distribution in ArcGIS:
Grey points are filtered out for the graphic since they have NULL values.
Xander Bakker. Thank you. Excellent idea. Really its very helpful for research community.
I have created random points (Number of points:1000) using create random tool under feature class. and I have given that point feature class as fc_pnt path,
fc_pnt = r'D:\TEST\Reference_RASTER\Random_Points\Random_pnts.shp'i am getting error, might be i didn't construct fc_pnt data properly
Traceback (most recent call last):
File "<module1>", line 45, in <module>
File "<module1>", line 34, in main
RuntimeError: A column was specified that does not exist.Hope i have problem with my point feature data set. may i know how to construct that point feature class.
Thank you.
