Call fields from a struct

Hi

I'm using the tensor toolbox and within that the NMF section. I have everything working perfectly except one thing, the initialisation. It uses a struct:

% INIT : A struct containing initial values. INIT.W and INIT.H should contain

% initial values of W and H of size (m x k) and (k x n), respectively.

% When INIT is not given, W and H are randomly initialized.

I can create the 1x1 struct containing INIT.W and INIT.H of the appropriate sizes with no problem. But when I try and call it, I don't seem to be able to do.

The function looks like this within the toolbox looks like this:

params.addParamValue('init',struct([]),@(x) isstruct(x));

So, I thought it should look like this within the line undertaking the NMF:

[W,H,iter,REC]=nmf(data_nmf,k, 'MIN_ITER',500,'tol',1e-7,'method','anls_bpp','init',struct([init.W, init.H]));

I've been reading all the previous questions on structures, read the matlab pages on structures and nmf and tried lots of variations on the above....but I still don't seem to be able to run it.

I'm clearly making a really daft mistake but I just can't see it! If anyone has used this toolbox and this part of it successfully I'd be most grateful to know how you ran the initialisation.

Thanks

Answer 1

[Dave B]

I'm a little confused, but I'll venture some guesses....

Do you have a struct init in your workspace (where you're calling the function from) with W and H fields? if so, I think you want:

[W,H,iter,REC]=nmf(data_nmf,k, 'MIN_ITER',500,'tol',1e-7,'method','anls_bpp','init',init);

Or do you have some other variable init in your workspace? If so, what is it?

If you don't have some init in your workspace, and your initial w and h were say 100 and 200:

[W,H,iter,REC]=nmf(data_nmf,k, 'MIN_ITER',500,'tol',1e-7,'method','anls_bpp','init',struct('W',100,'H',200));

that's equivalent to:

s=struct;
s.W=100;
s.H=200;
[W,H,iter,REC]=nmf(data_nmf,k, 'MIN_ITER',500,'tol',1e-7,'method','anls_bpp','init',s);

[James Alix]

Hi

Thanks for replying.

I had a struct init in the workspace and so the first answer worked. Can't believe I didn't see that!

Thanks++