CODEWITHSUNDEEP
rlogical-operators
user2510207
user2510207

Reputation: 27

Create dataframe from logical test

I've got what I know is a really easy question, but I'm stumped and seem to lack the vocabulary to seek out the answer effectively with the search bar.

I have a data frame full of numbers similar to this (though not of the same class)

 Dat <- structure(c(9L, 9L, 3L, 3L, 2L, 9L, 10L, 5L, 6L, 2L, 4L, 6L, 
 10L, 2L, 9L, 0L, 1L, 8L, 9L, 7L, 7L, 4L, 4L, 3L, 4L, 7L, 7L, 
 1L, 0L, 3L, 6L, 10L, 8L, 3L, 0L, 7L, 7L, 1L, 2L, 8L, 5L, 7L, 
 7L, 8L, 2L, 1L, 10L, 3L, 0L, 2L, 7L, 0L, 0L, 7L, 9L, 8L, 9L, 
 0L, 4L, 4L, 5L, 6L, 6L, 2L, 4L, 1L, 6L, 2L, 4L, 7L, 5L, 2L, 7L, 
 4L, 8L, 3L, 3L, 2L, 5L, 1L, 1L, 3L, 8L, 0L, 1L, 8L, 8L, 1L, 1L, 
 0L, 4L, 4L, 4L, 5L, 6L, 9L, 5L, 2L, 6L, 3L), .Dim = c(10L, 10L
 ))

All I want to do is replace all values > 5 with a 1, and all values less than 5 with a 0. I've gotten as far as getting a frame with TRUE and FALSE, but can't seem to figure out how to replace things.

 Datlog <- Dat > 5

Any help would be greatly appreciated. Thank you.

Upvotes: 0

Views: 61

Answers (1)

A5C1D2H2I1M1N2O1R2T1
A5C1D2H2I1M1N2O1R2T1

Reputation: 193527

If I read your question correctly, you'll kick yourself for the answer:

(Dat > 5) * 1

TRUE and FALSE in R equate to 1 and 0 respectively. As such, the more semantically correct way to do this would be something like:

out <- as.numeric(Dat > 5)
dim(out) <- dim(Dat)

The two step approach is required in this second approach because when you use as.numeric, the dims of the original data are lost.

One way to replace with different values would be to use factor:

out <- factor((Dat > 5), c(TRUE, FALSE), c("YES", "NO"))
dim(out) <- dim(Dat)

Another way would be basic subsetting and substitution:

out <- Dat
out[out > 5] <- 999
out[out <= 5] <- 0
out

Upvotes: 2

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