combine unequal length matrices in loop with cbind()

I have a simple question but it cost me hours. I would like to cbind() a matrix and a dataframe. The point is, they don't have equal lengths.

matrix:

condition

        [,1]

ILMN_1666845 TRUE

ILMN_1716400 TRUE

Data.frame

a

t1 t2 t3 t4 1 0 1 1 1

If I use cbind() without a loop, everything is ok and this is the result:

b<-cbind(condition,a) b

        condition t1  t2  t3  t4

ILMN_1666845 TRUE 0 1 1 1

ILMN_1716400 TRUE 0 1 1 1

But in a for loop I get the following error: Error in data.frame(..., check.names = FALSE) : arguments imply differing number of rows: 0, 1

Can anyone help me? Thanks!

For loop code:

for (p in 1:nrow(outcomes)) {

id <- apply(regulationtable, 1, function(i)

sum(i[1:length(regulationtable)] != outcomes[p,])==0)

idd<-as.matrix(id)

condition = subset(idd, idd[,1开发者_Go百科]==TRUE)

a<-as.data.frame(t(outcomes[p,]))

b<-cbind(condition,a)

write.table(b, "file.txt", append=TRUE)}

---

As far as I could read from your code, you try to cbind a possible empty object, which never works. That's also what the error is telling you. Probably at some point a is just empty, as there are no matches. So just add a condition

if(sum(id) !=0) { ... }

You could benefit quite a lot from rewriting your code to take this into account. I tried to guess what you wanted to do, and this code does exactly the same :

xx <- apply(outcomes,1,function(p){
    id <- apply(regulationtable,1,function(i)
      sum(i != p ) == 0)
    if(sum(id) !=0)
     cbind(as.data.frame(id[id]),t(p))
})

write.table(do.call(rbind,xx),file="file")

It returns you a list xx with, for every possible outcome, the genes that have the same regulationpattern. This is tested with :

outcomes <- expand.grid(c(0,1),c(0,1),c(0,1),c(0,1))

regulationtable <- data.frame(
    t1=sample(0:1,10,replace=T),
    t2=sample(0:1,10,replace=T),
    t3=sample(0:1,10,replace=T),
    t4=sample(0:1,10,replace=T)
)
rownames(regulationtable) <- paste("Gene",1:10,sep="-")