help spmat import
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Title

    spmat import -- Create an spmat object from a text file


Syntax

        spmat import objname using filename [, options]


    options               Description
    -------------------------------------------------------------------------
      noid                filename does not contain unique IDs
      nlist               filename contains a neighbor list
      geoda               filename was created by the GeoDa (TM) software
      idistance           convert distance data to inverse distances
      normalize(norm)     normalization method
      replace             replace objname
    -------------------------------------------------------------------------


Description

    spmat import creates the spmat object objname from the text file
    filename.

    By default, spmat import imports data from a space-delimited text file in
    which the first line contains the number of columns of the
    spatial-weighting matrix and, if applicable, the lower and upper band,
    followed by the matrix stored row-by-row with unique place identifiers
    recorded in the first column.


Options

    noid alerts spmat import that filename does not contain unique place
        identifiers.  If so, Stata will create IDs 1, ..., n.

    nlist specifies that the text file is in the neighbor-list format.  The
        first line of the file must contain the total number of places and,
        if the matrix is banded, the lower and upper band.  Each remaining
        line lists a place ID followed by its neighbors, if any.

    geoda specifes that filename is in the .gwt or .gal format created by the
        GeoDa (TM) software.

    idistance tells spmat that the data be converted to inverse distances.
        The value d will be converted to 1/d with the exception of the main
        diagonal, which will contain zero entries.

    normalize(norm) specifies the normalization method.  norm can be row,
        minmax, or spectral.

    replace allows objname to be overwritten if it already exists.


Example

    Setup
        . clear all
        . set memory 50m
        . use pollute
        . spmat contiguity cobj using pollutexy, id(id) normalize(minmax)
        . spmat export cobj using cobj.txt
        . spmat drop cobj

    Create the spmat object cobj from the file cobj.txt
        . spmat import cobj using cobj.txt


Also see

    Online:  spmat, spreg, spivreg, spmap, shp2dta, mif2dta (if installed)