Python Script to read from shapefile and insert in matrix.

GeorgeBentley — Tue, 09 Nov 2010 13:47:55 GMT

Hi Everyone,

I am working on a Python script that I could use some assistance with. I am trying to take the values within the "P_Area" and "P_Area_1" fields that reside in the Srcfile (variable name for shapefile of interest and insert these values into the first two columns of a matrix. Using Numpy I have managed to set up a n x m matrix with 179 rows and 360 columns. I could use some assistance with the next step of reading the values from these two fields and writing them to the matrix. Any help would be greatly appreciated.

I have attached the script that is in progress.

Re: Python Script to read from shapefile and insert in matrix.

ChrisMathers — Fri, 10 Dec 2021 22:24:44 GMT

Well it looks like the you are making a cursor in your defined function and trying to use it ouside the function which will cause you problems. If you want a list that contains all of the values for a field I would do it this way.

cursor=gp.SearchCursor(Srcfile)
row=cursor.Next()
P_Area=[]
P_Area1=[]
while row:
    P_Area.append(row.GetValue(P_Area))
    P_Area1.append(row.GetValue(P_Area1))
del cursor

That gives you two lists. One for each field. How do drop them into a numpy matrix Im not sure since I havnt used it, but this is a better way to get the lists. It may be easier to put the numbers into the matrix as you are taking them from the cursor instead of using the lists. I dont see how you can load a list into a numpy matrix though, at least from the numpy docs.

topic Python Script to read from shapefile and insert in matrix. in Geoprocessing Questions

Python Script to read from shapefile and insert in matrix.

Re: Python Script to read from shapefile and insert in matrix.