Here is an approach...probably there are more elegant ways
mydata=data.frame(ID=c("A","B","C","D","E"),val=c(.3,1.2,3.4,2.2,2.0))
index=expand.grid(1:nrow(mydata),1:nrow(mydata))
dif=data.frame(difference=mydata$val[index$Var2]-mydata$val[index$Var1])
rownames(dif)=paste(mydata$ID[index$Var2],"-",mydata$ID[index$Var1])
alessandro carletti wrote:
Hi,
I have a problem.
I have a data frame looking like:
ID val
A .3
B 1.2
C 3.4
D 2.2
E 2.0
I need to CREATE the following TABLE:
CASE DIFF
A-A 0
A-B -0.9
A-C -3.1
A-D -1.9
A-E -1.7
B-A ...
B-B ...
B-C
B-D
B-E
C-A
C-B
C-C
C-D
C-E
D-A
D-B
D-C
D-D
D-E
E-A
E-B
E-C
E-D
E-E
WHERE CASE IS THE COUPLE OF ELEMENTS CONSIDEREDM AND DIFF IS THE computed
DIFFERENCE between their values.
Could you give me suggestions?
Alessandro Carletti
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and provide commented, minimal, self-contained, reproducible code.
