Pecade - 6 months ago 36

R Question

I have three lists with Inf as a numeric and "NaN" as a character variable.

`v1<-list(1,Inf,3,4,5,6,"NaN")`

v2<-list(1,"NaN",3,4,5,6,5)

v3<-list(1,2,3,4,5,6,"NaN")

for the moment I can make a matrix with cbind, but the desired result is the code B).

A) What I got:

`matrix<-cbind(v1,v2,v3)`

v1 v2 v3

[1,] 1 1 1

[2,] Inf "NaN" 2

[3,] 3 3 3

[4,] 4 4 4

[5,] 5 Inf 5

[6,] 6 6 6

[7,]"NaN" 7 "NaN"

B) I want to get:

`v1 v2 v3`

[1,] 1 1 1

[2,] 3 3 3

[3,] 4 4 4

[4,] 6 6 6

Context:

I wanted to export into a .txt file some results located in 3 lists, the easy for me was to use cbind to get a matrix and use

`write.table(matrix, file="mymatrix.txt", row.names=FALSE, col.names=FALSE)`

Answer

Couple of suggestions regarding the problem.

1) It is better not to name a `matrix`

object as `matrix`

.

2) `NaN`

or `NA`

have a special meaning and are not character strings. By using quotes `"NaN"`

, it becomes difficult to apply the custom functions `is.nan/is.na`

to do any manipulations. So, we have to resort to `==/!=`

3) It is not clear why the individual `list`

are `cbind`

ed to a `matrix`

.

Based on the input data, we can loop through the columns of 'matrix' with `apply`

, then loop through each of the `list`

elements, check whether we have a finite element and is not a "NaN", get the `rowSums`

, negate (`!`

- converts the 0 elements to TRUE i.e. all the elements in the row are finite and all other values to FALSE). Use the logical index to subset the rows.

```
matrix[!rowSums(apply(matrix, 2, FUN = function(x)
sapply(x, function(y) !(is.finite(y) & y !="NaN")))),]
# v1 v2 v3
#[1,] 1 1 1
#[2,] 3 3 3
#[3,] 4 4 4
#[4,] 6 6 6
```