topic Re: Plotting Confidence Bands by Group in Graphics Programming

Plotting Confidence Bands by Group

dhrumil_patel — Thu, 03 Nov 2016 23:16:30 GMT

On SAS 9.3, I'm trying to plot the width of a custom confidence interval by year. For each year, I have three groups. Using the graph, I would like to visually inspect the width of the intervals by each group across year.

I am trying to do this by creating a stacked bar chart that uses an associated attribute map. The space from 0 to the lowerRange, I want to fill with white and the space from the lowerRange to the upperRange, I'd like to fill with a non-white color (here, orange). For each year, I'll have three stacked bars, one for each group.

I'm getting an error when specifying the same value for the group= option in the VBARPARM statement in PROC SGPLOT.

Here is the data:

data conditionData;

length model_year 8. price_type $ 15. grade_2 grade_3 grade_4 8.;

input model_year price_type $ grade_2 grade_3 grade_4;

datalines;

2002 lowerRange 2300 3600 .

2002 upperRange 3000 4400 .

2003 lowerRange . 4100 .

2003 upperRange . 4900 .

2004 lowerRange . 5200 6200

2004 upperRange . 6200 7100

;

run;

The attribute map I created is here:

data attrmap;
length id $ 15. value $ 20. fillcolor $ 9;
/*retain linecolor "black";*/
input id $ value fillcolor $;
datalines;
grade_2  avg_lowerRange  white
grade_2  avg_upperRange  orange
grade_3  avg_lowerRange  white
grade_3  avg_upperRange  orange
grade_4  avg_lowerRange  white
grade_4  avg_upperRange  orange
;
run;

Finally, here is the PROC SGPLOT code where I get the error:

proc sgplot data=test_trp dattrmap=attrmap noautolegend;
yaxis label='Auction Price';
vbarparm category=yearproduction response=grade_2 / 
	group=price_type attrid=grade_2
	barwidth=0.2 groupdisplay=stack
	discreteoffset=-0.4;
vbarparm category=yearproduction response=grade_3 / 
	group=price_type attrid=grade_3 
	barwidth=0.2 groupdisplay=stack
	discreteoffset=0;
vbarparm category=yearproduction response=grade_4 / 
	group=price_type attrid=grade_4
	barwidth=0.2 groupdisplay=stack
	discreteoffset=0.4;
run;

SAS issues a warning that "only one attribute id can be assigned to the price_type variable." Because of that, the bars for the last two groups are filled with default colors.

Is there a way I can correct this? Or another approach altogether?

I would appreciate any suggestions. Thank you!

Dhrumil

Re: Plotting Confidence Bands by Group

BrunoMueller — Fri, 04 Nov 2016 07:50:51 GMT

You could create new variables for each VBARPARM statement having the same content. Based on the code you provided, I put together this sample program.

data test_trp;
  length model_year 8. price_type $ 15. grade_2 grade_3 grade_4 8.;
  input model_year price_type $ grade_2 grade_3 grade_4;
  price_type2 = price_type;
  price_type3 = price_type;
  datalines;
2002  lowerRange  2300  3600  .
2002  upperRange 3000  4400  .
2003  lowerRange   .        4100  .
2003  upperRange  .        4900  .
2004  lowerRange   .        5200  6200
2004  upperRange  .        6200  7100
;

data attrmap;
length id $ 15. value $ 20. fillcolor $ 9;

retain linecolor "black";
input id $ value fillcolor $;
datalines;
grade_2  lowerRange  white
grade_2  upperRange  orange
grade_3  lowerRange  white
grade_3  upperRange  orange
grade_4  lowerRange  white
grade_4  upperRange  orange
;

proc sgplot data=test_trp dattrmap=attrmap noautolegend;
  yaxis label='Auction Price';
  vbarparm category=model_year response=grade_2 / 
    group=price_type attrid=grade_2
    barwidth=0.2 groupdisplay=stack
    discreteoffset=-0.4;
  vbarparm category=model_year response=grade_3 / 
    group=price_type2 attrid=grade_3 
    barwidth=0.2 groupdisplay=stack
    discreteoffset=0;
  vbarparm category=model_year response=grade_4 / 
    group=price_type3 attrid=grade_4
    barwidth=0.2 groupdisplay=stack
    discreteoffset=0.4;
run;

Bruno

Re: Plotting Confidence Bands by Group

dhrumil_patel — Fri, 04 Nov 2016 16:44:23 GMT

Thanks, Bruno. This works nicely.

Dhrumil