topic Re: making fishnet in Python Questions

making fishnet

nedamohammadi1 — Mon, 29 Apr 2013 16:45:45 GMT

Hello Every body !

I want to make a fishnet for around 80 images (.tif), I want to call data from a path and make a fishnet for raws and columns 2*2.
who has idea?
Regards
Nedaaaa

Re: making fishnet

JakeSkinner — Mon, 29 Apr 2013 16:48:38 GMT

You can use the Create Fishnet function to do this. If all your rasters are in one directory, you can iterate through each raster using the List Rasters function.

Re: making fishnet

nedamohammadi1 — Tue, 30 Apr 2013 10:07:58 GMT

Thank you so much Jake!
It seems it was helpful, I had problem in the reading of data!I wrote this script:

#import arcpy and arcgisscripting
import arcgisscripting

gp = arcgisscripting.create(9.3)
gp.overwriteOutput = 1

import arcpy

# Set the current workspace
gp.env.workspace = r"X:\mohammadi\finalmunichGIS\clip0ffishnet9000\clip"
# Get and print a list of GRIDs from the workspace
rasters = arcpy.ListRasters("*", "TIF")
for raster in rasters:
    print(raster)
# input hard-coded but you can make it a script tool parameter to make it an interactive input.
#in_fc = r"X:\mohammadi\finalmunichGIS\clip0ffishnet9000\clip" # this polygon feature class has several polygons.

rows = gp.SearchCursor(rasters)
row = rows.Next()

while row:
    feat = row.raster
    ext = feat.extent
    orig = str(ext.xmin) + " " + str(ext.ymin)
    yaxis = str(ext.xmin) + " " + str(ext.ymin + 100.00)
    opp_corner = str(ext.xmax) + " " + str(ext.ymax)
    print orig, yaxis, opp_corner

outPath = r"X:\mohammadi\finalmunichGIS\fishnet4500\4500.shp"+ str(row.OBJECTID)

result = gp.CreateFishnet_management(outPath, orig, yaxis, "0", "0", "2", "2", opp_corner,"NO_LABELS","#","POLYGON")
print(gp.GetMessages())

    row = rows.Next()

del row, rows

now error is in line 33: print(gp.GetMessages())
it is the first time I got such a problem?????

Re: making fishnet

JakeSkinner — Sat, 11 Dec 2021 22:45:25 GMT

Try the following:

import arcpy
from arcpy import env
env.workspace = r"X:\mohammadi\finalmunichGIS\clip0ffishnet9000\clip"

lstRasters = arcpy.ListRasters("*", "TIF")
for raster in lstRasters:
    xmin = arcpy.Describe(raster).extent.XMin
    ymin = arcpy.Describe(raster).extent.YMin
    xmax = arcpy.Describe(raster).extent.XMax
    ymax = arcpy.Describe(raster).extent.YMax
    ymin2 = arcpy.Describe(raster).extent.YMin + 10
    arcpy.CreateFishnet_management("fishnet_" + raster[:-4] + ".shp", str(xmin) + " " + str(ymin), str(xmin) + " " + str(ymin2), "0","0","2","2", str(xmax) + " " + str(ymax), "NO_LABELS", "#","POLYGON")

print "Finished"

Re: making fishnet

nedamohammadi1 — Tue, 30 Apr 2013 14:00:17 GMT

Thank you so much, it worked!!:D

Re: making fishnet

nedamohammadi1 — Thu, 02 May 2013 15:00:47 GMT

Dear Jake Skinner !!
thank you so much for your help!!now I want to divide this fishnets by clip_management, I wrote this script:

# only import arcpy - don't use arcgisscripting/gp at 10.x
import arcpy
from arcpy import env

arcpy.env.overwriteOutput = True ## 1

env.workspace = r"X:\mohammadi\finalmunichGIS\munich.gdb"

# in_fc is your polygon feature class
in_fc = r"X:\mohammadi\finalmunichGIS\fishnet4500"

fcList = arcpy.ListFeatureClasses("","Polygon","")
for fc in fcList:
    lyrFC = "lyrFC"

    # in_fc is your polygon feature class
    in_fc = fc

    # in_tif is your input
    in_raster = r"X:\mohammadi\finalmunichGIS\Testdatenoriginaldata\munich_subset.tif"

    # output location
    outPath = r"X:\mohammadi\finalmunichGIS\lastclip"

    arcpy.MakeFeatureLayer_management(in_fc,lyrFC)

    # get list of object ids
    objIDs = []
    objIDField = arcpy.Describe(lyrFC).OIDFieldName
    rows = arcpy.SearchCursor(lyrFC)
    row = rows.next()

    while row:
        objIDs.append(row.getValue(objIDField))
        row = rows.next()

    del row, rows

    # temp polygons
    copyFC = r"X:\mohammadi\finalmunichGIS\test.gdb\fc_parent1_1c"

    # one by one clip raster to polygons
    arcpy.env.workspace= outPath
    for objID in objIDs:
        where = "{0} = {1}".format(objIDField,objID)
        arcpy.SelectLayerByAttribute_management(lyrFC,"NEW_SELECTION",where)
        arcpy.CopyFeatures_management(lyrFC,copyFC)
        ext = arcpy.Describe(copyFC).Extent
        extString = "{0} {1} {2} {3}".format(ext.xmin, ext.ymin, ext.xmax, ext.ymax)
        out_raster = "{0}_clip{1}.tif".format(in_fc, objID)
        arcpy.Clip_management(in_raster, extString, out_raster, copyFC)
        print arcpy.GetMessages(0)

    arcpy.Delete_management(copyFC)

it works but it makes clip likes as before for me it means whole of fishnet not four clips of every fishnet!!!
what is your sugestion?
thanks
neda

Re: making fishnet

nedamohammadi1 — Tue, 07 May 2013 10:49:22 GMT

Dear Jake!

I need to make clip from that fishnet it almost work , the only problem is error 000732:

# only import arcpy - don't use arcgisscripting/gp at 10.x
import arcpy
from arcpy import env

arcpy.env.overwriteOutput = True ## 1

env.workspace = r"X:\mohammadi\finalmunichGIS\fishnet4500\fishnet4500.gdb"

# in_fc is your polygon feature class
#in_fc = r"X:\mohammadi\finalmunichGIS\fishnet4500"

fcList = arcpy.ListFeatureClasses("","Polygon","")
for fc in fcList:
    lyrFC = "lyrFC"

    # in_fc is your polygon feature class
    in_fc = fc

    # in_tif is your input
    in_raster = r"X:\mohammadi\finalmunichGIS\Testdatenoriginaldata\munich_subset.tif"

    # output location
    outPath = r"X:\mohammadi\finalmunichGIS\lastclip"

    arcpy.MakeFeatureLayer_management(in_fc,lyrFC)

    # get list of object ids
    objIDs = []
    objIDField = arcpy.Describe(lyrFC).OIDFieldName
    rows = arcpy.SearchCursor(lyrFC)
    row = rows.next()

    while row:
        objIDs.append(row.getValue(objIDField))
        row = rows.next()

    del row, rows

    # temp polygons
    copyFC = r"X:\mohammadi\finalmunichGIS\test.gdb\test"

    # one by one clip raster to polygons
    arcpy.env.workspace= outPath
    for objID in objIDs:
        where = "{1} = {0}".format(objIDField,objID)
        arcpy.SelectLayerByAttribute_management(lyrFC,"NEW_SELECTION",where)
        arcpy.CopyFeatures_management(lyrFC,copyFC)
        ext = arcpy.Describe(copyFC).Extent
        extString = "{0} {1} {2} {3}".format(ext.xmin, ext.ymin, ext.xmax, ext.ymax)
        out_raster = "{0}_clip{1}.tif".format(in_fc, objID)
        arcpy.Clip_management(in_raster, extString, out_raster, copyFC)
        print arcpy.GetMessages(0)

    arcpy.Delete_management(copyFC)

because of the name of clips , sometimes they are same so it makes problem , so I must change last part of script I mean loop !!
what do you sugest ?I mean the name of clips must not be 1,2,3,4 sth like as a, b, c , but I don,t know how to manage that .I am so new in python:)

Re: making fishnet

JakeSkinner — Tue, 07 May 2013 10:54:33 GMT

Are you trying to clip the fishnet polygon feature class by a directory of rasters?

Re: making fishnet

nedamohammadi1 — Tue, 07 May 2013 11:16:13 GMT

Yes I am going to do that, because my clips must be rasters or TIF , I want to use them in fragstats

Re: making fishnet

nedamohammadi1 — Tue, 07 May 2013 11:26:37 GMT

I must solve the problem in last part , Imean for the loop of :

for objID in objIDs:
        where = "{1} = {0}".format(objIDField,objID)
        arcpy.SelectLayerByAttribute_management(lyrFC,"NEW_SELECTION",where)
        arcpy.CopyFeatures_management(lyrFC,copyFC)
        ext = arcpy.Describe(copyFC).Extent
        extString = "{0} {1} {2} {3}".format(ext.xmin, ext.ymin, ext.xmax, ext.ymax)
        out_raster = "{0}_clip{1}.tif".format(in_fc, objID)
        arcpy.Clip_management(in_raster, extString, out_raster, copyFC)
        print arcpy.GetMessages(0)

because the name of clips are like as this for example:fishnet_fc_parent1_10_clip1_clip1
so 1, 2 , 3, 4 makes problem , because some of them are same.error 000732 and error 000725
😞

Re: making fishnet

nedamohammadi1 — Wed, 08 May 2013 17:15:20 GMT

I made some change in my code :

# only import arcpy - don't use arcgisscripting/gp at 10.x
import arcpy
from arcpy import env

arcpy.env.overwriteOutput = True ## 1
env.workspace = r"X:\mohammadi\finalmunichGIS\fishnet4500\fishnet4500plus.gdb"

def sendmsg (msg):
    print msg
    arcpy.AddMessage(msg)

fcList = arcpy.ListFeatureClasses("","Polygon","")

for fc in fcList:
    env.workspace = r"X:\mohammadi\finalmunichGIS\fishnet4500\fishnet4500plus.gdb"

    lyrFC = "lyrFC"
    sendmsg (fc)

    # in_fc is your polygon feature class
    in_fc = fc

    arcpy.MakeFeatureLayer_management(in_fc,lyrFC)

    # in_tif is your input
    in_raster = r"X:\mohammadi\finalmunichGIS\Testdatenoriginaldata\munich_subset.tif"

    # output location
    outPath = r"X:\mohammadi\finalmunichGIS\clip0ffishnet9000\lastclip"



    # get list of object ids
    objIDs = []
    objIDField = arcpy.Describe(lyrFC).OIDFieldName
    rows = arcpy.SearchCursor(lyrFC)
    row = rows.next()

    while row:
        objIDs.append(row.getValue(objIDField))
        row = rows.next()

    del row, rows

    # temp polygons
    copyFC = r"X:\mohammadi\finalmunichGIS\test.gdb\fc_parent1_1c"

    # one by one clip raster to polygons
    arcpy.env.workspace = outPath
    for objID in objIDs:
        where = "{0} = {1}".format(objIDField,objID)
        arcpy.SelectLayerByAttribute_management(lyrFC,"NEW_SELECTION",where)
        arcpy.CopyFeatures_management(lyrFC,copyFC)
        ext = arcpy.Describe(copyFC).Extent
        extString = "{0} {1} {2} {3}".format(ext.xmin, ext.ymin, ext.xmax, ext.ymax)
        out_raster = "{0}_clip{1}.tif".format(in_fc, objID)
        arcpy.Clip_management(in_raster, extString, out_raster, copyFC)
        print arcpy.GetMessages(0)

    arcpy.Delete_management(copyFC)
    arcpy.Delete_management(lyrFC)

but the error is this:error 999999:the table name is invalid
who can help me?
I run this code befor , but I don,t know why it has problem?
thanks alot

Re: making fishnet

JakeSkinner — Sat, 11 Dec 2021 22:45:28 GMT

Hi Neda,

From my understanding, you first created a 2x2 fishnet shapefile for each raster in a directory. You now want to clip each one of those rasters by each polygon in the fishnet. If that is correct, take a look at the following code:

import arcpy
from arcpy import env
env.workspace = r"C:\TIFFs"
env.overwriteOutput = 1

list = []

#append each raster to a list
lstFCs = arcpy.ListFeatureClasses("*")
for fc in lstFCs:
    list.append(fc)

#iterate through each raster
lstRasters = arcpy.ListRasters("*")
for raster in lstRasters:
    for n in list:
        #find the fishnet shapefile by checking if the raster name is in the shapefile name
        if raster.split(".")[0] in n:
            rows = arcpy.SearchCursor(n)
            for row in rows:
                FID = row.FID
                #create a feature layer for each polygon in the fishnet shapefile
                arcpy.MakeFeatureLayer_management(n, "FC_lyr", "FID = " + str(FID))
                #clip the raster by each polygon, and output a new TIFF to another directory
                arcpy.Clip_management(raster, "#", r"C:\TIFFs\Clip" + "\\" + raster + "_clip_" + str(FID) + ".tif", "FC_lyr", "256", "ClippingGeometry")

print "Finished"

Also, a quick note, when you are posting code, be sure to wrap it in CODE tags using the # symbol above. This will preserve the indentation. I believe you were previously wrapping the code with QUOTE tags.

Re: making fishnet

nedamohammadi1 — Fri, 10 May 2013 15:21:17 GMT

Sorry I didn,t have screen shot! I upload photo for you!