CODEWITHSUNDEEP
rdataframematrix
Galadriel
Galadriel

Reputation: 27

How to add names to rows and columns in existing R matrices

I'm working on R matrices and i am unable to add names to rows (titles) and columns(region) with this set of problem. My data set is as follows- 

terminator_1 <- c(66.1, 317.6, 657.2)
terminator_2 <- c(54.7, 261.9, 616.9)
terminator_3 <- c(45.6, 249.5, 547.1)

region <- c("UK", "US", "Other")
titles <- c("terminator_1", "terminator_2", "terminator_3")

I want to be able to add names to the matrix's rows (titles) and columns (region)

The am trying to get an o/p like the following- 

    terminator_1 terminator_2 terminator_3
  US 66.1 54.7 45.6

  UK 317.2 261.9 249.5

  Other 657.2 616.9 547.1

Upvotes: 0

Views: 547

Answers (2)

d.b
d.b

Reputation: 32538

sapply(mget(titles), setNames, region)
#      terminator_1 terminator_2 terminator_3
#UK            66.1         54.7         45.6
#US           317.6        261.9        249.5
#Other        657.2        616.9        547.1

Upvotes: 2

Maurits Evers
Maurits Evers

Reputation: 50668

Do you mean something like this?

mat <- cbind(sapply(ls()[grep("terminator", ls())], get))
rownames(mat) <- region
#      terminator_1 terminator_2 terminator_3
#UK            66.1         54.7         45.6
#US           317.6        261.9        249.5
#Other        657.2        616.9        547.1

Explanation: We use get to column-bind all numeric vectors that contain the string "terminator" from the current environment. Then use rownames to set the row names of the matrix.

Or much cleaner & more succinct using mget (thanks to @d.b)

mat <- do.call(cbind, mget(titles))    
rownames(mat) <- region

Upvotes: 2

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