topic Re: creating heat map of correlation matrix in Graphics Programming

creating heat map of correlation matrix

nstdt — Mon, 17 Apr 2017 14:07:52 GMT

Dear all,

I am using Chris Hemedinger's code posted here:

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

to get a heat map of my correlation matrix. The only problem is I have too many variables(>40) so the labels on the axis all overlap and aren't readable anymore.

I think there should be a fix - manipulating the X axis or Y axis display options --- but I'm a total novice with SAS graphics and am not sure what to do. The heat map itself is generated just fine, only the variable names are all lost. Maybe I should try truncating the varaible names?

Thanks for any advice!

Re: creating heat map of correlation matrix

ballardw — Mon, 17 Apr 2017 15:14:42 GMT

Easiest may be to change the height and width options on the the ODS GRAPHICS statement ODS Graphics/ height=10in width=10in may get you close, second would be to reduce the font size of the axis label text and third I would look closely at whether I needed all of the text currently displaying as an axis label. Shorter labels may help.

Re: creating heat map of correlation matrix

nstdt — Tue, 18 Apr 2017 12:47:22 GMT

Chris Hemedinger kindly gave a solution to my question posted on his blog:

If you want the labels and values to be readable, you might just need to increase the dimensions of the graph:

ods graphics /height=1500px width=1500px imagemap tipmax=4000;

Adding the TIPMAX option allows the higher number of hover-over tips to be included as well.

This gives better output, though I don't know how I would manage if I had more than 40 variables...

I tried other options (some suggested below) such as setting tickvalueattrs--- within the xaxisopt code:xaxisopts=(display=(line ticks tickvalues tickvalueattrs=(size=4pt weight=bold)))--- to reset the font but these did not work.

Re: creating heat map of correlation matrix

ballardw — Tue, 18 Apr 2017 15:51:26 GMT

@nstdt wrote:

Chris Hemedinger kindly gave a solution to my question posted on his blog:

If you want the labels and values to be readable, you might just need to increase the dimensions of the graph:

ods graphics /height=1500px width=1500px imagemap tipmax=4000;

Adding the TIPMAX option allows the higher number of hover-over tips to be included as well.

This gives better output, though I don't know how I would manage if I had more than 40 variables...

Shorter labels that key to a text table for reference perhaps. And sometimes the scope just needs to be reduced.