Error Using zeros; Size inputs must be scaler

function ampData = ampMeasure(filename, N, R)

% load a signal
[x, R] = audioread(filename);

% choose a subwindow size (in samples)
N = x * .125; 
% calculate how many subwindows there are in the signal
numWindows = floor(length(x)/N);

%make a multi-row column to store all the amp measurements
a = zeros(numWindows, 1);

% make a for loop that iterates once per subwindow
for i=1:numWindows
    % calculate the start/end sample range based on i
    startSamp = (i-1) * N + 1;
    endSamp = startSamp + (N-1);

    % get the RMS of this window
    a(i) = rmsAmp( x(startSamp:endSamp) );
    
    fprintf("the RMS amp of window %i is %f\n", i, a);
end
ampData = [a(i)];

end

% it says my error is on the line with a = zeros(numWindow, 1)
% I know the situation seems easy, but I don't get it??

[Prasad Reddy]

Please check weather numWindow is a scalar or nor ??

what does this command produce?? thatis important.

Answer 1

[Walter Roberson]

N = x * .125; should be

N = floor(length(x) * .125);