How to create null vector Matlab

Dear members

I have matrix with size M*N and vector with size 1*K

I want to create a null vector with length of N - length of K

I tried this :

V=zeros(1,length(N)-length(K));

but it doesn't work. Any solution please ?

Thank you.

[Just Manuel]

this would be easier if you told us what is not working. Do you get an error message? Or just an unexpected result?

As it stands, your code is valid.

[Afluo Raoual]

I get an unexpected result which is:

1*0 empty double row vector

[Just Manuel]

Yep, then go with Bjorn Gustavsson's answer.

Cheers

Manuel

Answer 1

[Bjorn Gustavsson]

First off if you've done something like:

N = 12;
M = 14;
K = 7;
Mtr = randn(M,N);
V = rand(1,K);
V=zeros(1,length(N)-length(K));

Then you only check the length of the 1-by-1 arrays N and K - and the difference of that is zero. If your N and K are your arrays you might have run into a situation where N < K, because this also happens when N < K. Perhaps you've mixed up the dimensions of your matrix and you meant to make something like this:

V=zeros(1,M - K);

HTH

[Afluo Raoual]

No, in my case N > K

I have N=7774 and K=5832

When I put zeros(1,7774-5832) it works, but with zeros(1, length(N)-length(K)) it doesn't work

[Just Manuel]

Yes, then omit the length call. Just do

zeros(1, N-K);

Cheers

Manuel

[Afluo Raoual]

It's done. Thank you :)

[Just Manuel]

You're welcome.