[GIS] ArcGIS, Edit Layer Extents with Python script

arcgis-desktoparcpypython

I would like to read and edit the Extent Values of each Layer in a MXD-file.

My code:

import arcpy

mxd = arcpy.mapping.MapDocument(r"D:\Work\myInFile.mxd")

for lyr in arcpy.mapping.ListLayers(mxd):

    if lyr.isFeatureLayer:

         # read
         print lyr.getExtent

         # write
         lyr.getExtent = ({XMin}, {YMin}, {XMax}, {YMax})


mxd.saveACopy(r"D:\Work\myOutFile.mxd")
del mxd

The getExtent method is described here But I'm not sure whether this is in any way the correct method.

Best Answer

from your code there is no problem listing layers and getting the extent of layers but i dont think writing method is correct. try the following code with Extent method:

import arcpy

arcpy.env.extent = arcpy.Extent(XMin,YMin,XMax,YMax)

i hope it helps you...

Related Solutions

[GIS] Understanding use of extents in ArcPy

Found my answer, was just a confusion on my part. Obviously a lot of brain work and ArcGIS help was involved, so if someone cares to explain further what exactly I did, it may help to clarify things for others with the same confusions I had.

For those interested, here is the solution I came up with:

#Define Geodatabase and workspace
    #gdb = r"F:\...\####.gdb"
    env.workspace = gdb
    env.scratchworkspace = gdb
    # Set extent
    extent = arcpy.Extent(XMIN,YMIN,XMAX,YMAX)
#List available Feature Classes in a List
    def FCs_in_GDB(gdb):
        try:
            fcs = []
            for fds in arcpy.ListDatasets('','feature') + ['']:
                for fc in arcpy.ListFeatureClasses('','',fds):
                    fcs.append(os.path.join(fds, fc))
            return fcs
        except:
            print ("An Error has occured in FCs_in_GDB().")
    fc_list = FCs_in_GDB(gdb)
#Process Describe() filter on Count function
    for fc in fc_list:
        try:
            name = arcpy.Describe(fc).name
            x = arcpy.Describe(fc).extent
            overlaps = x.overlaps(extent)
            contains = x.contains(extent)
            within = x.within(extent)
            if overlaps==True or contains==True or within==True:
                count = arcpy.GetCount_management(fc)
        except:
            print ("An Error has occurred in fc_list().")

QGIS – Define the Extent of QgsRasterCalculator Using Python

Since you are not actually performing any raster calculations, I would recommend using a more appropriate tool such as gdal_translate for this. You can call the command line utility as a library function in Python (Geo tips & tricks- GDAL and OGR utilities as library functions).

Here is an example of how to use it on your raster directory to clip your rasters to your study area and adjust the resolution to 5m with a bilinear re-sampling method (You can use a different method or if you don't want to resample, simply omit that argument). *just double check that the upper-left and lower-right corner coordinates are correct.

from osgeo import gdal
import os

in_folder = 'C:\\Documents\\Raster_files'
out_folder = 'C:\\Documents\\Processed'

ulx = 319660
uly = 4742843
lrx = 396425
lry = 4624088

testdir = os.scandir(in_folder)

for file in testdir:
    if file.name.endswith('.tif'):
        name = f'{os.path.splitext(file.name)[0]}_5m.tif'
        input = file.path
        output = os.path.join(out_folder, name)
        ds = gdal.Open(input)
        ds = gdal.Translate(output, ds, projWin = [ulx, uly, lrx, lry], xRes = 5, yRes = -5, resampleAlg = 'bilinear')
        ds = None

You can see more about translateOptions here.

Best Answer

Related Solutions

[GIS] Understanding use of extents in ArcPy

QGIS – Define the Extent of QgsRasterCalculator Using Python

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