18 lines
1.1 KiB
Mathematica
18 lines
1.1 KiB
Mathematica
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function ret = findAllZeroCrossings(x,y)
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% Finds all Zero-crossing of the function y = f(x)
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zci = @(v) find(v(:).*circshift(v(:), [-1 0]) <= 0); % Returns Approximate Zero-Crossing Indices Of Argument Vector
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zxidx = zci(y);
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if ~isempty(zxidx)
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for k1 = 1:numel(zxidx)
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idxrng = max([1 zxidx(k1)-1]):min([zxidx(k1)+1 numel(y)]);
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xrng = x(idxrng);
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yrng = y(idxrng);
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[yrng2, ~, jyrng] = unique(yrng); %yrng is a new array containing the unique values of yrng. jyrng contains the indices in yrng that correspond to the original vector. yrng = yrng2(jyrng)
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xrng2 = accumarray(jyrng, xrng, [], @mean); %This function creates a new array "xrng2" by applying the function "@mean" to all elements in "xrng" that have identical indices in "jyrng". Any elements with identical X values will have identical indices in jyrng. Thus, this function creates a new array by averaging values with identical X values in the original array.
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ret(k1) = interp1( yrng2(:), xrng2(:), 0, 'linear', 'extrap' );
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end
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else
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warning('No zero crossings found!')
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ret = nan;
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end
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end
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