86 lines
3.5 KiB
C
86 lines
3.5 KiB
C
// pdmath.h
|
|
// Elementary math on probability distributions
|
|
//
|
|
// (c) 2016 - Nico Palermo, IV3NWV - Microtelecom Srl, Italy
|
|
// ------------------------------------------------------------------------------
|
|
// This file is part of the qracodes project, a Forward Error Control
|
|
// encoding/decoding package based on Q-ary RA (repeat and accumulate) LDPC codes.
|
|
//
|
|
// qracodes is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
// qracodes is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with qracodes source distribution.
|
|
// If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
|
|
#ifndef _pdmath_h_
|
|
#define _pdmath_h_
|
|
|
|
#include <memory.h>
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#define PD_NDIM(nlogdim) ((1<<(nlogdim))
|
|
#define PD_SIZE(ndim) ((ndim)*sizeof(float))
|
|
#define PD_ROWADDR(fp,ndim,idx) (fp+((ndim)*(idx)))
|
|
|
|
const float *pd_uniform(int nlogdim);
|
|
// Returns a pointer to a (constant) uniform distribution of the given log2 size
|
|
|
|
#define pd_init(dst,src,ndim) memcpy(dst,src,PD_SIZE(ndim))
|
|
// Distribution copy
|
|
|
|
void pd_memset(float *dst, const float *src, int ndim, int nitems);
|
|
// Copy the distribution pointed by src to the array of distributions dst
|
|
// src is a pointer to the input distribution (a vector of size ndim)
|
|
// dst is a pointer to a linear array of distributions (a vector of size ndim*nitems)
|
|
|
|
void pd_imul(float *dst, const float *src, int nlogdim);
|
|
// In place multiplication
|
|
// Compute dst = dst*src for any element of the distrib give their log2 size
|
|
// src and dst arguments must be pointers to array of floats of the given size
|
|
|
|
float pd_norm(float *pd, int nlogdim);
|
|
// In place normalizazion
|
|
// Normalizes the input vector so that the sum of its components are one
|
|
// pd must be a pointer to an array of floats of the given size.
|
|
// If the norm of the input vector is non-positive the vector components
|
|
// are replaced with a uniform distribution
|
|
// Returns the norm of the distribution prior to the normalization
|
|
|
|
void pd_fwdperm(float *dst, float *src, const int *perm, int ndim);
|
|
// Forward permutation of a distribution
|
|
// Computes dst[k] = src[perm[k]] for every element in the distribution
|
|
// perm must be a pointer to an array of integers of length ndim
|
|
|
|
void pd_bwdperm(float *dst, float *src, const int *perm, int ndim);
|
|
// Backward permutation of a distribution
|
|
// Computes dst[perm[k]] = src[k] for every element in the distribution
|
|
// perm must be a pointer to an array of integers of length ndim
|
|
|
|
float pd_max(float *src, int ndim);
|
|
// Return the maximum of the elements of the given distribution
|
|
// Assumes that the input vector is a probability distribution and that each element in the
|
|
// distribution is non negative
|
|
|
|
int pd_argmax(float *pmax, float *src, int ndim);
|
|
// Return the index of the maximum element of the given distribution
|
|
// The maximum is stored in the variable pointed by pmax if pmax is not null
|
|
// Same note of pd_max applies.
|
|
// Return -1 if all the elements in the distribution are negative
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif // _pdmath_h_
|