Splits wavelet_mul into two parts. And fixes a lot of warnings.

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){
+		// does not calculate "last two" elements (it does not assume periodicity)
-			assert(is_pow_of_two(size) && is_pow_of_two(stride) && 4*stride <= size);
+		// 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);
+			assert(x && is_pow_of_two(size) && size >= 4);
-			for(int i = 1; i <= size / 4; i <<= 1){
+			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);
+			assert(x && is_pow_of_two(size) && size >= 4);
-			for(int i = size / 4; i >= 1; i >>= 1){
+			for(unsigned int i = size / 4; i >= 1; i >>= 1){
 				wavelet_inv(x, x[size-i], x[size-2*i], size, i);
 			}
 		}