Dear Sir/Madam, I'm getting a problem with a R-code which converts a data frame to a matrix.
It first generate a (m^(n-m) * m) matrix A and then regenerate another matrix B having less dimension than A which satisfy some condition. Now I wish to assign each row of B to a vector as individual. My problem is when I set any choice of (n,m) except m=1 it works fine but setting m=1 I got the error : Error in B[i, ] : incorrect number of dimensions. Moreover if (n,m) is large (say, (20,8)) I got the error : Error: cannot allocate vector of size 3.0 Gb. I know this is due to large dimension of matrix A. How to solve this problem. My code is given below: ********************************************************************** n=5 m=3 R=numeric(0) # Generate all possible m-tuple ( variables having range 0 to n ) in a ( m^(n-m) * m ) matrix r = expand.grid(rep(list(0:(n-m)), m)) write.table(r,file="test.txt",row.names=FALSE,col.names=FALSE) a= read.table(file="test.txt",sep="",header=FALSE) A= data.matrix(a) #......................................................................................... # Generate matrix whose rowsum = n-m meet.crit = apply(A, 1, function(.row) any((sum(.row)) == n-m)) # criteron for being rowsum = n cbind(A, meet.crit) # Checking rowsum = n for each row -m B=A[meet.crit,] # Generate matrix #......................................................................................... for(i in 1:choose(n-1,m-1)){ R=B[i,] } *************************************************************************** Can you please help me how to get rid of these errors. Thanking you in advance. Regards Ritwik Bhattacharya Senior Research Fellow SQC & OR UNIT, KOLKATA INDIAN STATISTICAL INSTITUTE Voice : +91 9051253944 This mail is scanned by Ironport ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.