Philip Ueno Philip Ueno - 1 year ago 62
R Question

Loop in R: how to save the outputs?

I am trying to save the data from a loop of logical tests.

So I have the following data:

T1 <- matrix(seq(from=100000, to=6600000,length.out=676),26,26) # a matrix of 26X26 - here with illustrive values

minmax <- seq(from=1,to=49,by=1) # creates a sequence
Fstep <- 6569141.82/minmax # define a vector from 0 to 6569141.82 with 49 divisions
F <- rev(round(Fstep,0)) # round the vector values and re order them

I have runned the following loop

for (i in 1:49) {
print(T1 > F[i]) # I used print to see the results in the screen

This loop returns me 49 matrices filled in with logical values (True or false). Each matrix is the comparison of T1 against each of the 49 positions F[i] (F[1], ...., F[49])

I need to have the values in those matrices for further using as adjacency matrices for network plots. However when I can't neither assign those logical values to an matrix, neither save them in csv values using "write.matrix".

So, I need to have 49 - matrices "W" filled in with logical values (T or F). I already got those values by the loop above but I can't get it as an object or as collection of csv. files.

I tried

W<-matrix(0,26,26) #create an empty matrix to assign the logical arguments
for (i in 1:49){
W[i] <- T1>F[i] # I used print to see the results in the screen

which returns the following warning

Warning messages:
1: In W[i] <- (T1 > F[i]) :
number of items to replace is not a multiple of replacement length

I also tried a different setting in which all the matrices I compare have the same dimensions.

create.M <- function(F){ # a function to transform each position F[i] into a 26X26 matrix
for (i in 1:49) {

Loop.T1 <- function(T1){ # a function to replicate T1(49 times)
for ( i in 1:49) {

and compared the two outputs


which returns


Answer Source

Store each boolean matrix as an item in a list:

result <- vector("list",49)
for (i in 1:49)
   result[[i]] <- T1>F[i] # I used print to see the results in the screen

#Print the first matrix on screen
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