Hi Arijit,

Have you considered using parfor and left indexing? Here's an example from the docs that generates a large matrix out of smaller chunks:`ms = matrix(0, rows=2, cols=3*10)parfor (v in 1:10, check=0) { mv = matrix(v, rows=2, cols=3) ms[,(v-1)*3+1:v*3] = mv}`

SystemML has a special data structure to represent a matrix block that is all zeros, so creating a very large matrix of zeros (first line in the above listing) is an inexpensive operation.

Fred

arijit chakraborty ---05/02/2017 09:48:13 AM---Hi, Our process is generating multiple matrix, of same size, but number of matrix is random. Finally

From: arijit chakraborty <akc14@hotmail.com>

To: "dev@systemml.incubator.apache.org" <dev@systemml.incubator.apache.org>

Date: 05/02/2017 09:48 AM

Subject: Combining Multiple Matrix

Our process is generating multiple matrix, of same size, but number of matrix is random. Finally, we combine all the smaller matrix to get a final large matrix.

The way we are creating the large matrix is, we are creating a blank matrix and then update the matrix once each smaller matrix is created. This is inefficient because we are initially creating a large matrix, which sometimes take more than required space.

So is there any method where we can combined all the final smaller matrix together into a larger matrix? For rbind and cbind, we have to use loops to merge the matrix.

Thank you!

Arijit