help spmat dta
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Title

    spmat dta -- Create an spmat object from a rectangular Stata dataset


Syntax

        spmat dta objname varlist [if] [in] [, options]


    options               Description
    -------------------------------------------------------------------------
      id(varname)         variable containing unique IDs
      idistance           convert distance data to inverse distances
      normalize(norm)     normalization method
      replace             replace objname
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Description

    spmat dta creates the spmat object objname from a Stata dataset
    containing the entries of an n x n spatial-weighting matrix.  The number
    of variables in varlist should be equal to the number of observations in
    the dataset.


Options

    id(varname) specifies a variable containing unique place identifiers.  If
        this option is omitted, spmat dta will create the IDs 1, ..., n.

    idistance tells spmat that the data are to 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
        . spmat use cobj using pollute.spmat
        . spmat export cobj using cobj.txt
        . spmat drop cobj
        . insheet using cobj.txt, delimiter(" ") clear
        . rename v1 id

    Create the spmat object cobj containing a contiguity matrix stored in the
    variables v2-v542
        . spmat dta cobj v*, id(id) replace


Also see

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