Help with isnan with two matrices of unequal dimensions

Hi,

I have two matrices of unequal dimensions. pol1 = 1 x 22648 and pol2 has dimensions of 1 X 22706.

I wanted to plot one against the other and I want to check the cells for which both values exist.

I tried good_use=find(~isnan(pol1) & ~isnan(pol2))

but I get an error ' Matrix dimensions must agree '.

How do I solve this error ?

[Guillaume]

What does "plot one against the other" mean, when the two vector are different lengths?

What if element 22706 of the second vector is not nan? What does that mean for the other vector which only has 22648 elements?

[Sayantan Sahu]

Basically, I want to plot one against the other.

I want to find the indices for which both pol1 and pol2 have values. How would I achieve that ?

[Guillaume]

"I want to find the indices for which both pol1 and pol2 have values"

You still haven't explained what that means when the two vectors have different length. Using shorter vectors, if

pol1 = [1   nan 2 nan]
pol2 = [nan 3   4 nan  nan 5]

what result would you expect ?

[Sayantan Sahu]

yes use shorter vectors. In the example you provide, it should plot pol1(3) and pol2(3) and so on. To summarize wherever its numeric values not NaN.

Answer 1

[Guillaume]

"yes use shorter vectors"

So in effect, you're telling us to truncate the longer one so that it is the same length as the other? If you do that then your initial expression will work.

%truncate longer vector to the size of the shorter vector:
veclength = min(numel(po1), numel(pol2));
pol1 = pol1(1:veclength); 
pol2 = pol2(1:veclength);

%your original search, find not needed
good_use = ~isnan(pol1) & ~isnan(pol2)

%plot
plot(pol1(good_use), pol2(good_use))

Answer 2

[Greg Heath]

Separate the 2 searches.

Hope this helps

Thank you for formally accepting my answer

Greg

[Sayantan Sahu]

How would I do that ?