CODEWITHSUNDEEP
r
Swati Suryavanshee
Swati Suryavanshee

Reputation: 13

Substract minimum value of row from each element of row in dataframe,

I have a data frame

   A  B  C  D
r1 10  7 19 11
r2  5  5  7  8
r3 12  9 13 11
r4  8 10 11  9

I want to create 2 data frames whose values are:

  1. Subtracting min value in row from each element of that row,
  2. Subtracting min value in column from each element of that column.

I got function for column

d1=transform(d,A=A-(min(A)),B=B-(min(B)),C=C-(min(C)),D=D-(min(D)))

Result I get is is as below,

> d1
  A B  C D

r1 5 2 12 3

r2 0 0  0 0

r3 7 4  6 3

r4 3 5  4 1

what function I should use to get result for rows, which I want is

> d2
  A B  C D

r1 0 2  9 1

r2 0 5  2 3

r3 1 3  2 0

r4 0 7  3 1

(min value of row is subtracted from each item of the row)

Upvotes: 1

Views: 502

Answers (3)

akrun
akrun

Reputation: 887951

We can use pmin

d - do.call(pmin, d)

Or by columns

library(matrixStats)
d - colMins(as.matrix(d))[col(d)]

Upvotes: 0

cbo
cbo

Reputation: 1763

You can also use the apply fonction with :

# 1 for the rows
apply(d, 1, function(x){x-min(x)}
# 2 for the columns 
apply(d, 2, function(x){x-min(x)}

Upvotes: 1

Captain Hat
Captain Hat

Reputation: 3257

If I've understood your question, you could just run your 'function for columns' on the transpose of your data frame. Transposed data frames turn into matrices, so you'll need to turn it back into a data frame:

transpose <- as.data.frame(
  t(yourDataFrame)
)

d2 <- transform(transpose ,A=A-(min(A)),B=B-(min(B)),C=C-(min(C)),D=D-(min(D)))

By the way this question could be clearer. I recommend you read How to create a minimal, reproducible Example: https://stackoverflow.com/help/minimal-reproducible-example

Upvotes: 1

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