replacing Nan with 0

I have an excel file that I need to replace nan with zeros

I am using this piece of code and am getting error : Array indices must be positive integers or logical values

Error in "isnan(auPoints(r,c)) = 0;

I am not sure how to fix it or what I am doing wrong

for r = 4:1:22
    for c = 2:1:29
        if isnan(auPoints(r,c))
            isnan(auPoints(r,c))
        end
    end
end

Answer 1

[Star Strider]

Try this:

auPoints - fillmissing(auPoints, 'constant',0);

It might be advisable to save the output to a different variable, in order to preserve the original ‘auPoints’ matrix.

See the documentation for fillmissing (R2016b and later versions) for details.

Answer 2

[madhan ravi]

 auPoints(isnan(auPoints(r, c))) = 0

[Caroline Prekker]

I'm not sure where I would put that. It is telling me that c exceeds array bounds

[madhan ravi]

Well it’s assumed that c was within the bounds.

Try this: (OBSCURE)

 auPoints =  subsasgn(auPoints, substruct('()', {isnan(auPoints)}), 0)

Answer 3

[jonas]

The line does not work because the left part just returns a logical.

isnan(auPoints(r,c)) = 0

It is similar to writing

isnan(NaN) = 0

...which makes no sense but returns the same error message

For this type of basic operation it is better to make use of logical indexing. For example, if you want to replace all your NaNs with zeros, you can write the following

mask = isnan(auPoints);
auPoints(mask) = 0;

The first line returns a logical array (1's and 0's) with the same size as the original array. This array is then used to index the original array. Faster and easier than loops.

More about logical indexing and indexing in general here.

[Caroline Prekker]

this gave me an error saying "unrecognized function or variable 'mask'"

[jonas]

I don't see how that is possible. The variable mask is literally defined in the first out of the two lines.

Still, you could try the following:

auPoints(isnan(auPoints)) = 0

Note that this is exactly the same, just reduced to one line

[Houss Leng]

I have this error Undefined function 'isnan' for input arguments of type 'table'.

[Walter Roberson]

https://www.mathworks.com/help/matlab/ref/fillmissing.html like Star Strider suggests