113 lines
2.6 KiB
C
113 lines
2.6 KiB
C
#include "linear.h"
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#include <stdlib.h>
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int point_v[1024] = {0};
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int point_l[1024] = {0};
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int point_cnt = 0;
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float k = 0;
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float b = 0;
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float theory_point[300] = {0};
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float linearity = 0;
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int test_cnt = 1;
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uint8_t save_data[101];
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uint8_t vol_loc_data[2000];
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int point_v_max,max_point,point_v_min,min_point;
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float bias_local = 0;
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extern double fabs(double __x);
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/// <LinearFit>
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/// 利用两点法进行线性拟合 y = kx + b,
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/// <x,y—存放长度与电压的数组>
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void linear_fit()
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{
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// Ax+By+C=0
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float A = 0;
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float B = 0;
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float C = 0;
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point_v_max = -9999;
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point_v_min = 9999;
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for (int i = 0; i < point_cnt; i++)
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{
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if(point_v[i] > point_v_max)
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{
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point_v_max = point_v[i];
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max_point = i;
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}
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if(point_v[i] < point_v_min)
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{
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point_v_min = point_v[i];
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min_point = i;
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}
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}
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A = point_v[max_point] - point_v[min_point];
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B = point_l[min_point] - point_l[max_point];
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C = point_l[max_point] * point_v[min_point] - point_l[min_point] * point_v[max_point];
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k = -(A / B);
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b = -(C / B);
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}
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/// <summary>
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/// 更新数组y，替换为电压理论值
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void linear_val()
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{
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for (int i = 0; i < point_cnt; i++)
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{
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theory_point[i] = k * point_l[i] + b;
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}
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}
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int write_start_addr = 0;
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void get_linearity()
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{
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float max_bias = 0;
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linear_fit();
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linear_val();
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for (int i = 0; i < point_cnt; i++)
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{
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if(fabs(max_bias) < fabs(point_v[i] - theory_point[i]))
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{
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max_bias = point_v[i] - theory_point[i];
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bias_local = point_l[i];
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}
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//
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vol_loc_data[0 + 2*i] = ((uint16_t)point_v[i] >> 8) & 0xFF;
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vol_loc_data[1 + 2*i] = (uint16_t)point_v[i] & 0xFF;
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vol_loc_data[1000 + 2*i] = ((uint16_t)point_l[i] >> 8) & 0xFF;
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vol_loc_data[1001 + 2*i] = (uint16_t)point_l[i] & 0xFF;
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//
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}
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linearity = fabs(max_bias / (point_v_max - point_v_min));
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//
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test_cnt++;
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if(test_cnt > 10)
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test_cnt = 1;
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save_data[0 + (test_cnt-1)*10] = ((uint16_t)(linearity * 10000) >> 8) & 0xFF;
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save_data[1 + (test_cnt-1)*10] = (uint16_t)(linearity * 10000) & 0xFF;
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save_data[2 + (test_cnt-1)*10] = ((uint16_t)(bias_local) >> 8) & 0xFF;
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save_data[3 + (test_cnt-1)*10] = (uint16_t)(bias_local) & 0xFF;
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save_data[4 + (test_cnt-1)*10] = ((uint16_t)(point_cnt) >> 8) & 0xFF;
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save_data[5 + (test_cnt-1)*10] = (uint16_t)(point_cnt) & 0xFF;
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save_data[6 + (test_cnt-1)*10] = ((uint16_t)(point_v_min) >> 8) & 0xFF;
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save_data[7 + (test_cnt-1)*10] = (uint16_t)(point_v_min) & 0xFF;
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save_data[8 + (test_cnt-1)*10] = ((uint16_t)(point_v_max) >> 8) & 0xFF;
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save_data[9 + (test_cnt-1)*10] = (uint16_t)(point_v_max) & 0xFF;
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save_data[100] = test_cnt;
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at24cxx_write(write_start_addr,save_data,101);
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at24cxx_write(1000 * (2 * test_cnt - 1),vol_loc_data,2000);
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//
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}
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