Hi,
I was hoping someone could help figure out how to write code for R to do the below.
I have data that looks like below. Variables, sid and pid are strings, slope is numeric. I need R to get me the mean of slopes for all pid's nested within each sid if there are more than one pid's nested within sid.
If there is only pid for a sid, like for 2.1 below, I want R to write a 0.
In the data below, I want to get the mean of slopes for pid (1.1; 4.1; and 5.1) because they are nested within sid 1.1 and so on.
Thanks in advance for any suggestions.
Swaroop
sid pid slope
1.1 1.1 2
1.1 4.1 3
1.1 5.1 2
2.1 5.1 3
3.2 1.2 2
3.2 1.7 3
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