| | |
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| | | if (focal_loss) { |
|---|
| | | // Focal Loss |
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| | | float alpha = 0.5; // 0.25 or 0.5 |
|---|
| | | //float gamma = 2; // hardcoded in many places of the grad-formula |
|---|
| | | //float gamma = 2; // hardcoded in many places of the grad-formula |
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| | | |
|---|
| | | int ti = index + stride*class_id; |
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| | | float pt = output[ti] + 0.000000000000001F; |
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| | | //float grad = -(1 - pt) * (2 * pt*logf(pt) + pt - 1); // http://blog.csdn.net/linmingan/article/details/77885832 |
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| | | float grad = (1 - pt) * (2 * pt*logf(pt) + pt - 1); // https://github.com/unsky/focal-loss |
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| | | // http://fooplot.com/#W3sidHlwZSI6MCwiZXEiOiItKDEteCkqKDIqeCpsb2coeCkreC0xKSIsImNvbG9yIjoiIzAwMDAwMCJ9LHsidHlwZSI6MTAwMH1d |
|---|
| | | float grad = -(1 - pt) * (2 * pt*logf(pt) + pt - 1); // http://blog.csdn.net/linmingan/article/details/77885832 |
|---|
| | | //float grad = (1 - pt) * (2 * pt*logf(pt) + pt - 1); // https://github.com/unsky/focal-loss |
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| | | |
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| | | for (n = 0; n < classes; ++n) { |
|---|
| | | delta[index + stride*n] = (((n == class_id) ? 1 : 0) - output[index + stride*n]); |
|---|
