91 lines
2.9 KiB
C
91 lines
2.9 KiB
C
/**
|
|
* Marlin 3D Printer Firmware
|
|
* Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
|
|
*
|
|
* Based on Sprinter and grbl.
|
|
* Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
|
|
*
|
|
* This program 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.
|
|
*
|
|
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* Incremental Least Squares Best Fit By Roxy and Ed Williams
|
|
*
|
|
* This algorithm is high speed and has a very small code footprint.
|
|
* Its results are identical to both the Iterative Least-Squares published
|
|
* earlier by Roxy and the QR_SOLVE solution. If used in place of QR_SOLVE
|
|
* it saves roughly 10K of program memory. And even better... the data
|
|
* fed into the algorithm does not need to all be present at the same time.
|
|
* A point can be probed and its values fed into the algorithm and then discarded.
|
|
*
|
|
*/
|
|
|
|
#include "MarlinConfig.h"
|
|
|
|
#if ENABLED(AUTO_BED_LEVELING_UBL) || ENABLED(AUTO_BED_LEVELING_LINEAR)
|
|
|
|
#include "Marlin.h"
|
|
#include "macros.h"
|
|
#include <math.h>
|
|
|
|
struct linear_fit_data {
|
|
float xbar, ybar, zbar,
|
|
x2bar, y2bar, z2bar,
|
|
xybar, xzbar, yzbar,
|
|
max_absx, max_absy,
|
|
A, B, D, N;
|
|
};
|
|
|
|
void inline incremental_LSF_reset(struct linear_fit_data *lsf) {
|
|
memset(lsf, 0, sizeof(linear_fit_data));
|
|
}
|
|
|
|
void inline incremental_WLSF(struct linear_fit_data *lsf, const float &x, const float &y, const float &z, const float &w) {
|
|
// weight each accumulator by factor w, including the "number" of samples
|
|
// (analagous to calling inc_LSF twice with same values to weight it by 2X)
|
|
lsf->xbar += w * x;
|
|
lsf->ybar += w * y;
|
|
lsf->zbar += w * z;
|
|
lsf->x2bar += w * x * x; // don't use sq(x) -- let compiler re-use w*x four times
|
|
lsf->y2bar += w * y * y;
|
|
lsf->z2bar += w * z * z;
|
|
lsf->xybar += w * x * y;
|
|
lsf->xzbar += w * x * z;
|
|
lsf->yzbar += w * y * z;
|
|
lsf->N += w;
|
|
lsf->max_absx = max(FABS(w * x), lsf->max_absx);
|
|
lsf->max_absy = max(FABS(w * y), lsf->max_absy);
|
|
}
|
|
|
|
void inline incremental_LSF(struct linear_fit_data *lsf, const float &x, const float &y, const float &z) {
|
|
lsf->xbar += x;
|
|
lsf->ybar += y;
|
|
lsf->zbar += z;
|
|
lsf->x2bar += sq(x);
|
|
lsf->y2bar += sq(y);
|
|
lsf->z2bar += sq(z);
|
|
lsf->xybar += x * y;
|
|
lsf->xzbar += x * z;
|
|
lsf->yzbar += y * z;
|
|
lsf->max_absx = max(FABS(x), lsf->max_absx);
|
|
lsf->max_absy = max(FABS(y), lsf->max_absy);
|
|
lsf->N += 1.0;
|
|
}
|
|
|
|
int finish_incremental_LSF(struct linear_fit_data *);
|
|
|
|
#endif
|
|
|