[R] R vector

[arun]

HI,
Not sure if this is what you wanted.
mat1<- matrix(c(1, 1, -1, -1, 1, -1, -1, -2, 1, 1, 1, 1), byrow=TRUE, nc=4)


fun1<- function(mat){
         matP<- mat
    matN<- mat
    matP[matP<0]<- NA
    matN[matN>0]<- NA
    resP<-rowSums(matP,na.rm=TRUE)/ncol(matP)
    resN<- rowSums(matN,na.rm=TRUE)/ncol(matN)
    res<- rbind(resP,resN)
    row.names(res)<- c("Mean_Pos","Mean_Neg")
    res
    }
fun1(mat1)
#         [,1]  [,2] [,3]
#Mean_Pos  0.5  0.25    1
#Mean_Neg -0.5 -1.00    0
A.K.


hello, 

when i use the function rowMeans, which is sum/n, can i divide 
it in 2 parts, -> Sum(just positive values)/n and Sum(just negative 
values)/n. i need both for my regression but dont know how to do it. 

for example we have the matrix 

1  1  -1  -1   -> rowMeans([1:3 , 2])  just positive -> 1 
1 -1 -1  -2                                                          
                    1/2  here not 0 because we dont use the -1 
1 1   1   1                                                                                1 


thanks for helping