How to reduce the time of calculation for a matrix with size of 24 million by 8 ?

Hi,

I have a matrix of size 24,000,000 x 8 with integer numbers, for example consider this;

a=[...
34600  34602   33576   33574  297769  297771  296745  296743
34601  34603   33577   33575  297770  297772  296746  296744
34602  34604   33578   33576  297771  297773  296747  296745
34603  34605   33579   33577  297772  297774  296748  296746
34604  34606   33580   33578  297773  297775  296749  296747
34605  34607   33581   33579  297774  297776  296750  296748
34606  34608   33582   33580  297775  297777  296751  296749
34607  34609   33583   33581  297776  297778  296752  296750
34608  34610   33584   33582  297777  297779  296753  296751]

I wanna renumber its member such that the member with minimum amount become 1 and it continues renumbering till reach to maximum member:

 member=reshape(a,(size(a,1)*size(a,2)),1);
 member=unique(member);
 member=sortrows(member);
 Newmember=(1:size(member,1))';
 renFun=@(x) Newmember(member==x);
 Renumbered_a=arrayfun(renFun,a);

It takes too much time to finish the procedure for 24 million rows. Any suggestion to reduce the time of calculation?

Many thanks in advance,

Arash

[Jan]

After calling unique, you overwrite the answer in the next line already. Therefore this wastes time only.

[Arash]

Jan, Thanks for your time.

Answer 1

[Matt J]

 [~,~,Renumbered_a]=unique(a(:));
 Renumbered_a=reshape(Renumbered_a,size(a));

[Arash]

Thank you Matt, it was awesome.