use std::hypot

Base/Math/FourierTransform.cpp

@@ -306,9 +306,7 @@ void FourierTransform::fft2amp(complex2d_t& source, double2d_t& result)
     for (int i = 0; i < ws.h; i++) {
         int k = (i == 0) ? 0 : ws.h - i;
         for (int j = 0; j < ws.w_fftw; j++) {
-            double re = source[i][j].real();
-            double im = source[i][j].imag();
-            result[i][j] = sqrt(re * re + im * im);
+            result[i][j] = std::hypot(source[i][j].real(), source[i][j].imag());
             if (j != 0)
                 result[k][ws.w_real - j] = result[i][j];
         }