CODEWITHSUNDEEP
r
bountiful
bountiful

Reputation: 814

Extract data from row names and insert into table

I have a data frame that looks like

                ML1    ML1 SD       ML2    ML2 SD ...
aPhysics0 0.8730469 0.3329205 0.5950521 0.4908820
aPhysics1 0.8471074 0.3598839 0.6473829 0.4777848
aPhysics2 0.8593750 0.3476343 0.7031250 0.4568810
aPhysics3 0.8875000 0.3159806 0.7000000 0.4582576
aPhysics4 0.7962963 0.4027512 0.7654321 0.4237285
...

And I want to use the row names to create a data frame that looks like

     Institution Subject Class       ML1    ML1 SD       ML2    ML2 SD ...
[1,]           A Physics     0 0.8730469 0.3329205 0.5950521 0.4908820
[2,]           A Physics     1 0.8471074 0.3598839 0.6473829 0.4777848
[3,]           A Physics     2 0.8593750 0.3476343 0.7031250 0.4568810
[4,]           A Physics     3 0.8875000 0.3159806 0.7000000 0.4582576
[5,]           A Physics     4 0.7962963 0.4027512 0.7654321 0.4237285
...

What would be the best way to do this?

Upvotes: 1

Views: 98

Answers (2)

Arun
Arun

Reputation: 118879

Assuming your data.frame is df,

header <- as.data.frame(do.call(rbind, strsplit(gsub("Physics", " Physics ", 
                rownames(df)), " ")))
names(header) <- c("Institution", "Subject", "Class")
cbind(header, df)
df.out <- cbind(header, df)
df.out$Institution <- toupper(df.out$Institution)

If you've more subjects (generalised solution):

header <- as.data.frame(do.call(rbind, strsplit(gsub("^([a-z])(.*)([0-9])$", 
                 "\\1 \\2 \\3", rownames(df)), " ")))
names(header) <- c("Institution", "Subject", "Class")
df.out <- cbind(header, df)
df.out$Institution <- toupper(df.out$Institution)

Upvotes: 3

James
James

Reputation: 66864

Assuming the row names are of the form (1 lowercase char-character string-1 digit number), you can use some regex with gsub:

#test data
x <- data.frame(ML1=runif(5),ML2=runif(5),row.names=paste0("aPhysics",1:5))

#logic
transform(x, Institution=toupper(gsub("^([a-z])([a-zA-Z]+)([0-9])$","\\1",rownames(x))), Subject=gsub("^([a-z])([a-zA-Z]+)([0-9])$","\\2",rownames(x)), Class=gsub("^([a-z])([a-zA-Z]+)([0-9])$","\\3",rownames(x)))
                 ML1       ML2 Institution Subject Class
aPhysics1 0.51680701 0.4102757           A Physics     1
aPhysics2 0.60388358 0.7438400           A Physics     2
aPhysics3 0.26504243 0.7598557           A Physics     3
aPhysics4 0.55900273 0.5263205           A Physics     4
aPhysics5 0.05589591 0.7903568           A Physics     5

Upvotes: 3

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