How do I convert the weird magnitudes in the results to zero ?

Hi,

When I run the below program, I got some "NaN" in the results. So, I want to convert those "NaN" to be "Zeros" and I think the way to do it is using the for-loop but I am not sure how to do it due to the meshgrid, any idea please?

"

[x,y] = meshgrid(-5: .125: 5, -5: .125: 5);

x1 = -1;

y1 = 0;

V_x1 = ((y-y1)./((x-x1).^2+(y-y1).^2));

V_x1 = V_x1 (:)

fid = fopen('outputData.txt','wt');

fprintf(fid,'%.8f\n',V_x1);

fclose(fid);

"

Answer 1

[Mischa Kim]

JMS, use something like

 data = [1 2 NaN; 3 NaN 4];
 data(isnan(data)) = 0;

[JMS]

Yours might work for very short data length but when you have a lot of them, how do you specify at which point you need to convert them?

I think I need to do something like

"

ones = find(V_x1==NaN)

V_x1(ones)=0

"

But it doesn't work! It doesn't recognize 'NaN'

[Mischa Kim]

Not quite sure I understand...

 data = randi(2,10^1)    % create 10-by-10 with 1s and 2s
 data(data==2) = NaN     % replace 2s by NaNs
 tic
 data(isnan(data)) = 0   % replace NaNs by 0s
 toc                     % ...computation time

This approach will also work for larger matrices.

Try increasing the number of elements to 10^2 or 10^3 and don't forget to add semi-colons for larger matrices.

[JMS]

Now it does work like

find_NaN = find(isnan(V_x1))

ones = (find_NaN)

V_x1(ones) = 0;

Thanks Mischa Kim!