The READ_SPR function reads a row-indexed sparse array. Row-indexed sparse arrays are created using the SPRSIN function and written to a file using the WRITE_SPR function.
            This routine is written in the IDL language. Its source code can be found in the file read_spr.pro in the lib subdirectory of the IDL distribution.
            Examples
            Suppose we have already saved a row-indexed sparse array to a file named sprs.as, as described in the documentation for the WRITE_SPR routine. To read the sparse array from the file and store it in a variable sprs, use the following command:
            sprs = READ_SPR('sprs.as')
            Syntax
            Result = READ_SPR(Filename)
            Return Value
            Returns the row-indexed sparse array from the specified file.
            Arguments
            Filename
            A scalar string specifying the name of the file containing a row-indexed sparse array.
            Version History
            
            See Also
            FULSTR, LINBCG, SPRSAB, SPRSAX, SPRSIN, WRITE_SPR