Scatter plot with gradient for 3rd dimension...

[nobyrnes]

Hey,
I am looking to make a 2d scatter plot but to use a gradient for the third dimension. Ive seen some gradients used for a proc gmap but I dont know if I can use this for a scatter???

My dataset looks like

a b c
x y N

N is from 0 to 50, so I need 50 colors but I need it displayed as a gradient.

All help appreciated.
Thanks,
Niall

 

[ChrisW75]

If you can set a "color=" option for the point which allows you to set a variable for the colour then all you need to do is calculate the colour for each point in a prior dataset. I've done something similar to this for a 3D scatter-plot turning it into a 4D chart.

creating the colours though is a bit tricky.
Here's a chunk of code I wrote some time back which does exactly that. i haven't looked at this in ages, but I thik this does pretty much what you want.

data dat1;
  infile cards dlm=',' dsd;

  input rank_frequency
        rank_recency
		rank_value
		count;

		vip = .;

cards;
;

data dat2;
  infile cards dlm=',' dsd;

  input rank_frequency
        rank_recency
		rank_value
		count;

		vip = 1;

cards;
1,0,0,470
1,0,1,66
1,1,1,4616
1,1,2,18
1,2,1,50
1,2,2,5784
2,0,0,1468
2,0,1,274
2,1,1,26773
2,1,2,100
2,2,1,352
2,2,2,88290
;
run;

data alldat;
  set dat1 dat2;
run;

proc summary data=alldat nway;
 class rank_frequency rank_recency rank_value;
 var count;
 output out=allsum(drop=_type_ _freq_) sum=;
run;

proc sql;
  select max(count)  as max
        ,min(count)  as min
  from allsum
  ;
quit;

******
HLS numbers
Hue        = 201       = 0C9 Hex
Light      = variable
Saturation = 86        = 56 HEX

Need to scale the range of Light over the range of our counts
Max count = 110781
Max Light = 256  (actually 255, but it's 0-255)
110781/256 = 432.
****;

data allsum2;
  set allsum;
  
  * value of light variable... *;
  decval = floor(count/433);
  hexval = put(decval,hex2.);

  colour = 'H0CF' !! hexval !! '56';


  *colRGB = "%HLSTORGB(colour)";

run;

proc format;
  value $colfmt
    '' = ''
	;

  value rnkfmt
    0 = 'Low'
	1 = 'Medium'
	2 = 'High'
	;

  value vipfmt
    . = 'Regular'
	1 = 'VIP'
	;
run;

ods html file='C:\coltest.htm';
proc report data=allsum2 nowd;
  columns count colour;

  define count /order;
  define colour /display style=[background=$colfmt.];
run;
ods html close;



goptions reset=all;
proc goptions;
run;


ods html path='c:\'
         file='test.htm';
proc g3d data=allsum2;
  scatter rank_recency*rank_frequency=rank_value /color=colour shape='balloon'
                                                  size=5 noneedle;
run;
quit;
ods html close;

I hope that this helps.
Chris.

Chris
Business Analyst, Code Monkey, Data Wrangler.
SAS Guru.