topic Box and Whisker Plots with p-value included in Graphics Programming

Box and Whisker Plots with p-value included

Bailey — Thu, 14 Aug 2014 01:59:35 GMT

I am looking for a nice way to represent information on a given study for my classroom. I have two separate groups A and B and want to compare them (hoping that B is statistically significantly better than A). How can I program this? I am very new to this and not sure what to do! I think a box an whisker plot would look nice, but also want the p-value shown on the top comparing the two.

A 2.7

A 0.0

A 3.1

A 4.6

B 6.2

B 5.2

B 3.5

B 3.6

B 5.9

Any help is appreciated! Thank you

Re: Box and Whisker Plots with p-value included

ballardw — Thu, 14 Aug 2014 15:14:25 GMT

You will need to run a test that creates p-values. Depending on the version of SAS you are using then you can add that value to a graph using an annotate dataset with your graph procedure.

Also, is that your actual data or do you have more records? Tests for a small sample is displayed are going to much different than for a larger sample. Also when compare (test) are you looking at means or distribution or something else?

Re: Box and Whisker Plots with p-value included

RandyCollica — Thu, 14 Aug 2014 17:15:47 GMT

The SAS code below takes your data set and reads the A and B into a variable called GROUP and the measures into a variable called VALUE. I then ran the TTEST procedure with plots=box. The output shows the p-values in a table and the boxplot below if that is okay. This is one of the easiest ways I could think of. The SAS output is contained in the attached pdf file. All the best - Randy

data work.compare;

length group $1;
input group value;
cards;

A 2.7

A 0.0

A 3.1

A 4.6

B 6.2

B 5.2

B 3.5

B 3.6

B 5.9

;
run;
ods graphics on;

proc ttest data=work.compare plots=box;
class group;

var value;
ods graphics off;

Re: Box and Whisker Plots with p-value included

stat_sas — Thu, 14 Aug 2014 17:32:50 GMT

Hi,

This can provide the boxplot with p value added on it.

ods graphics on;

ods select boxplot;

proc anova data=have;

class group;

model value=group;

quit;

ods graphics off;

Re: Box and Whisker Plots with p-value included

Bailey — Thu, 14 Aug 2014 20:00:36 GMT

Is there anyway on the box-plot that I could include all the data points?

Both your answer (RandyCollica) and (stat@sas) answers are exactly what I needed!! Thank you

Re: Box and Whisker Plots with p-value included

stat_sas — Thu, 14 Aug 2014 21:31:14 GMT

Check proc boxplot that allows to put stats on the box plot. I don't think it will allow to put all data points.