2017-01-25 22:43:29 +01:00

144 lines
3.5 KiB
C++

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/*
Polygon linear fit
Author: Siddharth Bharat Purohit
*/
#include "polyfit.h"
#include "matrix_alg.h"
int polyfitter::init(uint8_t order)
{
_forder = order + 1;
VTV = new double[_forder * _forder];
if (VTV == NULL) {
return -1;
}
VTY = new double[_forder];
if (VTY == NULL) {
return -1;
}
memset(VTV, 0, sizeof(double)*_forder * _forder);
memset(VTY, 0, sizeof(double)*_forder);
return 0;
}
void polyfitter::update(double x, double y)
{
update_VTV(x);
update_VTY(x, y);
}
void polyfitter::update_VTY(double x, double y)
{
double temp = 1.0f;
printf("O %.6f\n", (double)x);
for (int8_t i = _forder - 1; i >= 0; i--) {
VTY[i] += y * temp;
temp *= x;
printf("%.6f ", (double)VTY[i]);
}
printf("\n");
}
void polyfitter::update_VTV(double x)
{
double temp = 1.0f;
int8_t z;
for (uint8_t i = 0; i < _forder; i++) {
for (int j = 0; j < _forder; j++) {
printf("%.10f ", (double)VTV[i * _forder + j]);
}
printf("\n");
}
for (int8_t i = 2 * _forder - 2; i >= 0; i--) {
if (i < _forder) {
z = 0.0f;
} else {
z = i - _forder + 1;
}
for (int8_t j = i - z; j >= z; j--) {
uint8_t row = j;
uint8_t col = i - j;
VTV[row * _forder + col] += (double)temp;
}
temp *= x;
}
}
bool polyfitter::fit(double res[])
{
//Do inverse of VTV
double *IVTV = new double[_forder * _forder];
if (VTV == NULL) {
return false;
}
if (inverse4x4(VTV, IVTV)) {
for (uint8_t i = 0; i < _forder; i++) {
for (int j = 0; j < _forder; j++) {
printf("%.10f ", (double)IVTV[i * _forder + j]);
}
printf("\n");
}
for (uint8_t i = 0; i < _forder; i++) {
res[i] = 0.0f;
for (int j = 0; j < _forder; j++) {
res[i] += IVTV[i * _forder + j] * (double)VTY[j];
}
printf("%.10f ", res[i]);
}
return true;
}
return false;
}