show cell values in heat map of a correlation matrix

GreggB — Mon, 25 Oct 2021 17:30:09 GMT

this code came from Chris Hemedinger's blog:

https://blogs.sas.com/content/sasdummy/2013/06/12/correlations-matrix-heatmap-with-sas/

I want to include the correlation coefficient in each cell of the heat map. If I hover over the output I see the value of r but I cannot output it.

/* Prepare the correlations coeff matrix: Pearson's r method */
%macro prepCorrData(in=,out=);
  /* Run corr matrix for input data, all numeric vars */
  proc corr data=&in. noprint
    pearson
    outp=work._tmpCorr
    vardef=df
  ;
  run;
 
  /* prep data for heat map */
data &out.;
  keep x y r;
  set work._tmpCorr(where=(_TYPE_="CORR"));
  array v{*} _numeric_;
  x = _NAME_;
  do i = dim(v) to 1 by -1;
    y = vname(v(i));
    r = v(i);
    /* creates a lower triangular matrix */
    if (i<_n_) then
      r=.;
    output;
  end;
run;
 
proc datasets lib=work nolist nowarn;
  delete _tmpcorr;
quit;
%mend;

  /* Create a heat map implementation of a correlation matrix */
ods path work.mystore(update) sashelp.tmplmst(read);
 
proc template;
  define statgraph corrHeatmap;
   dynamic _Title;
    begingraph;
      entrytitle _Title;
      rangeattrmap name='map';
      /* select a series of colors that represent a "diverging"  */
      /* range of values: stronger on the ends, weaker in middle */
      /* Get ideas from http://colorbrewer.org                   */
      range -1 - 1 / rangecolormodel=(cxD8B365 cxF5F5F5 cx5AB4AC);
      endrangeattrmap;
      rangeattrvar var=r attrvar=r attrmap='map';
      layout overlay / 
        xaxisopts=(display=(line ticks tickvalues)) 
        yaxisopts=(display=(line ticks tickvalues));
        heatmapparm x = x y = y colorresponse = r / 
          xbinaxis=false ybinaxis=false
          name = "heatmap" display=all;
        continuouslegend "heatmap" / 
          orient = vertical location = outside title="Pearson Correlation";
      endlayout;
    endgraph;
  end;
run;

/* Build the graphs */
ods graphics /height=600 width=800 imagemap;
 
%prepCorrData(in=sashelp.cars,out=cars_r);
proc sgrender data=cars_r template=corrHeatmap;
   dynamic _title="Corr matrix for SASHELP.cars";
run;
 
%prepCorrData(in=sashelp.iris,out=iris_r);
proc sgrender data=iris_r template=corrHeatmap;
   dynamic _title= "Corr matrix for SASHELP.iris";
run;
 
/* example of dropping categorical numerics */
%prepCorrData(
  in=sashelp.pricedata(drop=region date product line),
  out=pricedata_r);
proc sgrender data=pricedata_r template=corrHeatmap;
  dynamic _title="Corr matrix for SASHELP.pricedata";
run;

Re: show cell values in heat map of a correlation matrix

Reeza — Mon, 25 Oct 2021 17:44:26 GMT

Here's a different way, but it controls the colour shading levels a bit more but overall and the code is simpler using SGPLOT instead.

https://gist.github.com/statgeek/566dda98173a5a28a6e4147317547959

Re: show cell values in heat map of a correlation matrix

GreggB — Mon, 25 Oct 2021 18:26:31 GMT

Do you know how to control the overall size of the matrix? This is my output.

Re: show cell values in heat map of a correlation matrix

Reeza — Mon, 25 Oct 2021 18:59:01 GMT

Since it's SGPLOT you can use the standard ODS GRAPHICS options to control the size of the graph.

https://documentation.sas.com/doc/en/vdmmlcdc/8.1/grstatproc/n0yadqm4wsfapgn1hzekfvu1ex0g.htm

ods graphics on / width=4.5in height=3.5in;

topic Re: show cell values in heat map of a correlation matrix in SAS Programming

show cell values in heat map of a correlation matrix

Re: show cell values in heat map of a correlation matrix

Re: show cell values in heat map of a correlation matrix

Re: show cell values in heat map of a correlation matrix