将.m转换为.mex以提高倍频

Question

I have a .m script that runs rather slowly in Octave (about 2 minutes typically), and not quite so slowly in MATLAB (about 7 seconds), and I presume the performance would be enhanced by compiling the program to a .mex file (especially for Octave). Unfortunately, the MATLAB compiler function mcc no longer supports the -x option to generate a .mex file.

Is there a workaround for this?

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Edit: In response to the comments

Below code's purpose is to smooth a spectrum while leaving high power regions mostly intact. It does this by taking local averages with a window size that depends on the magnitude of the spectrum at a point.

I do this with just a simple for loop, which is why it's so slow (vectorizing won't work easily because it would require a matrix with so many elements as to exhaust the available memory.

I am working with sound vectors that have ~600,000 elements, so the matrix would need ~3*10^11 elements, which is even too big for a sparse matrix on my 32 bit computer.

function smoothsig=smoothnoise(sig,wins,method)
% Smooths a signal "sig", leaving hi power regions intact (mostly).
% "wins" is a window size for smoothing
% "method" determines the relative smoothing of various parts of the spectrum
% "method" can be a handle to any function <=1 on [0,1] 

mx=max(abs(sig)); mn=min(abs(sig)); range=mx-mn;
len=(size(sig)); len=len(1);

if ~(exist('method','var'))
    method=1;
end

winsize=round(wins* winfunction((abs(sig)-mn)/range,method) );
smoothsig=zeros(size(sig));

for k=1:wins
    winsz=min(k-1,winsize(k));
    smoothsig(k)=mean(sig(k-winsz:k+winsz));
end

for k=wins+1:len-wins
    winsz=winsize(k);
    smoothsig(k)=mean(sig(k-winsz:k+winsz));
end

for k=len+1-wins:len
    winsz=min(len-k,winsize(k));
    smoothsig(k)=mean(sig(k-winsz:k+winsz));
end

end

%-------------------------------------------------------------
function y=winfunction(x, method)
    % Determines the window function
    if isa(method, 'function_handle')
        y=method(x);
    elseif isscalar(method) & method==1         % Uniform window size
        y=ones(size(x));
    elseif isvector(method) & method(1)==2      % Sharp cutoff for window size
        y=x<method(2);
    elseif isvector(method) & method(1)==3      % Polynomial change
        y=(1-x).^method(2);
    end
end

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• I'm not very familiar with C++, so I would prefer to do this in a more automated way than re-coding by hand in another language, if possible.

• I had not hear about .oct files, so I'll investigate that, but also see the above remark (I'm not fluent with C++).

Answer 1

如果您试图从MATLAB代码自动生成C代码，然后将其编译为.mex文件以提高速度，则此功能现在存在于MATLAB Coder产品中，而不是MATLAB Compiler中。