repo2/atari_chips/pokeyv2/SID/investigation/sig_sigmoid.m
| 1186 | markw | function res = sig_sigmoid(x)
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%Another option - SID-sigmoid...
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%Ref:Efficient digital implementation of the sigmoid
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%function for reprogrammable logic
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%M.T. Tommiska
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%337p
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x = min(x,8);
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x = max(x,-8);
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sgn = sign(x);
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x = x.*sgn;
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| 1324 | markw | x = floor(x*8)/8;
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| 1186 | markw | ||
sigmoidreal = @(x) 1./(1.+e.^-x);
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y = sigmoidreal(x);
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| 1324 | markw | y = floor(y*128)/128;
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| 1186 | markw | ||
res = y;
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res(sgn<0) = 1-res(sgn<0);
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end
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