help spmat graph
-------------------------------------------------------------------------------

Title

    spmat graph -- Draw an intensity plot of the spatial-weighting matrix W
                     contained in an spmat object


Syntax

        spmat graph objname [, options]


    options                            Description
    -------------------------------------------------------------------------
    Main
      blocks([(stat)] p)               plot matrix in p x p blocks

    Y axis, X axis, Titles, Legend, Overall
      twoway_options                   any options other than by() documented
                                         in [G] twoway_options
    -------------------------------------------------------------------------


Description

    spmat graph draws an intensity plot of the spatial-weighting matrix W
    contained in the spmat object objname.  Zero elements are plotted in
    white; the remaining elements are partitioned into 16 bins of equal
    length and assigned gray-scale colors gs0-gs15; see [G] colorstyle.


Options

        +------+
    ----+ Main +-------------------------------------------------------------

    blocks() divides the matrix into blocks of size p and plots block
        maximums.  To plot a statistic other than the default maximum,
        specify the optional stat argument. For example, to plot block
        medians, specify blocks((p50) p).  The supported statistics include
        those returned by summarize, detail; see summarize for a complete
        list.

        +-----------------------------------------+
    ----+ Y axis, X axis, Titles, Legend, Overall +--------------------------

    twoway_options are any of the options documented in [G] twoway_options,
        excluding by().  These include options for titling the graph (see [G]
        title_options) and for saving the graph to disk (see [G]
        saving_option).


Example

    Setup
        . spmat use cobj using pollute.spmat

    Plot the contiguity matrix contained in the spmat object cobj in 5 x 5
    blocks
        . spmat graph cobj, blocks(5)


Also see

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