From edd9a0345626f3a141f40b59fc84b3853b495403 Mon Sep 17 00:00:00 2001 From: Joshua Moerman Date: Sat, 4 Jan 2014 22:46:02 +0100 Subject: [PATCH] Splits wavelet_mul into two parts. And fixes a lot of warnings. --- wavelet/wavelet2.hpp | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) diff --git a/wavelet/wavelet2.hpp b/wavelet/wavelet2.hpp index 2b176aa..5d97935 100644 --- a/wavelet/wavelet2.hpp +++ b/wavelet/wavelet2.hpp @@ -22,19 +22,28 @@ namespace wvlt{ return x[0] * coef[0] + x[stride] * coef[1] + x[2*stride] * coef[2] + x[3*stride] * coef[3]; } - // will overwrite x, x1 and x2 are next elements, or wrap around + // will calculate part of wavelete transform (in place!) // size is size of vector x (so x[size-1] is valid) - inline void wavelet_mul(double* x, double x1, double x2, unsigned int size, unsigned int stride){ - assert(is_pow_of_two(size) && is_pow_of_two(stride) && 4*stride <= size); + // does not calculate "last two" elements (it does not assume periodicity) + // calculates size/stride - 2 elements of the output + inline void wavelet_mul_base(double* x, unsigned int size, unsigned int stride){ + assert(x && is_even(size) && is_pow_of_two(stride) && 4*stride <= size); - for(int i = 0; i < size - 2*stride; i += 2*stride){ + for(unsigned int i = 0; i < size - 2*stride; i += 2*stride){ double y1 = inner_product(x + i, evn_coef, stride); double y2 = inner_product(x + i, odd_coef, stride); x[i] = y1; x[i+stride] = y2; } + } + + // x1 and x2 are next elements, or wrap around + // calculates size/stride elements of the output + inline void wavelet_mul(double* x, double x1, double x2, unsigned int size, unsigned int stride){ + assert(x && is_even(size) && is_pow_of_two(stride) && 4*stride <= size); + wavelet_mul_base(x, size, stride); - int i = size - 2*stride; + unsigned int i = size - 2*stride; double y1 = x[i] * evn_coef[0] + x[i+stride] * evn_coef[1] + x1 * evn_coef[2] + x2 * evn_coef[3]; double y2 = x[i] * odd_coef[0] + x[i+stride] * odd_coef[1] + x1 * odd_coef[2] + x2 * odd_coef[3]; x[i] = y1; @@ -44,16 +53,16 @@ namespace wvlt{ // will overwrite x, x2 and x1 are previous elements, or wrap around // size is size of vector x (so x[size-1] is valid) inline void wavelet_inv(double* x, double x1, double x2, unsigned int size, unsigned int stride){ - assert(is_pow_of_two(size) && is_pow_of_two(stride) && 4*stride <= size); + assert(x && is_even(size) && is_pow_of_two(stride) && 4*stride <= size); - for(int i = size - 2*stride; i >= 2*stride; i -= 2*stride){ + for(unsigned int i = size - 2*stride; i >= 2*stride; i -= 2*stride){ double y1 = inner_product(x + i - 2*stride, evn_coef_inv, stride); double y2 = inner_product(x + i - 2*stride, odd_coef_inv, stride); x[i] = y1; x[i+stride] = y2; } - int i = 0; + unsigned int i = 0; double y1 = x2 * evn_coef_inv[0] + x1 * evn_coef_inv[1] + x[i] * evn_coef_inv[2] + x[i+stride] * evn_coef_inv[3]; double y2 = x2 * odd_coef_inv[0] + x1 * odd_coef_inv[1] + x[i] * odd_coef_inv[2] + x[i+stride] * odd_coef_inv[3]; x[i] = y1; @@ -61,15 +70,15 @@ namespace wvlt{ } inline void wavelet(double* x, unsigned int size){ - assert(is_pow_of_two(size) && size >= 4); - for(int i = 1; i <= size / 4; i <<= 1){ + assert(x && is_pow_of_two(size) && size >= 4); + for(unsigned int i = 1; i <= size / 4; i <<= 1){ wavelet_mul(x, x[0], x[i], size, i); } } inline void unwavelet(double* x, unsigned int size){ - assert(is_pow_of_two(size) && size >= 4); - for(int i = size / 4; i >= 1; i >>= 1){ + assert(x && is_pow_of_two(size) && size >= 4); + for(unsigned int i = size / 4; i >= 1; i >>= 1){ wavelet_inv(x, x[size-i], x[size-2*i], size, i); } }