Spaghetti Plots Where Subject Changes Groups

[thanksforhelp12]

Hello,

I am attempting to draw a spaghetti plot that has a single line per subject but some subjects change groups during the study period (crossover) - for this subject, I want the single line to be two colors (eg red when group 1 and blue when group 2). How can I go about doing this? My current code is below not achieving the desired results. Basically for patients who switch treatment groups mid-study their line color should change when they switch. Thanks so much.

proc sgplot data=data;
  title 'Study Results by Treatment Group';
  series x=Time y=Score / group=patient 
               grouplc=arm name='grouping';
  keylegend 'grouping' / type=linecolor;
run;

[Reeza]

I would probably create a combined variable that indicates group and patient and then use a discrete attribute table to control the colours manually.

[Rick_SAS]

For a discussion and some code that describes Reeza's idea, see "Series plot with varying attributes" 

[thanksforhelp12]

Thanks to both of you. I actually stumbled upon that post incidentally this weekend.

So it seems if I have 100s of subjects I have to manually code every one of their lines?

[Rick_SAS]

Not necessarily. Post your data. Maybe the DATA step can produce the recoding automatically. Do you have SAS/IML?

[Reeza]

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@thanksforhelp12 wrote:

Thanks to both of you. I actually stumbled upon that post incidentally this weekend.

So it seems if I have 100s of subjects I have to manually code every one of their lines?

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Depends on how you define manually coding, but you should be able to have a data driven solution - I would assume you could use some basic IF/THEN statements to create your data appropriately.