CODEWITHSUNDEEP
rmatrixheatmapigraph
Antonio Alaia
Antonio Alaia

Reputation: 23

How to convert a matrix (rectangular) with dummy variables into a square matrix with numeric?

I have this situation, in which I have about 200.000 observations ("source") that follow 8 different "target".
If they follow that target is 1 otherwise is 0 like in the simplified example below:

source target1 target2 target3
source1 1 0 1
source2 0 1 1
source3 1 1 1

Now, I want to know who follow more target and, consequently, how many times a same source follows more than one target, in other words, in each cell I want to know how many times both conditions are verified.
This would be the idea:

(blank) target1 target2 target3
target1 2 1 2
target2 1 2 2
target3 2 2 3

Upvotes: 0

Views: 43

Answers (1)

DaveArmstrong
DaveArmstrong

Reputation: 21937

library(dplyr)
dat <- tibble::tribble(
  ~source,  ~target1,   ~target2,   ~target3,
"source1",  1,  0,  1,
"source2",  0,  1,  1,
"source3",  1,  1,  1)

mat <- dat %>% select(-source) %>% as.matrix()
crossprod(mat)
#>         target1 target2 target3
#> target1       2       1       2
#> target2       1       2       2
#> target3       2       2       3

Created on 2022-11-27 by the reprex package (v2.0.1)

Upvotes: 0

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