my_math.c 1.9 KB

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  1. #include "my_math.h"
  2. #include "stdint.h"
  3. #include "stdarg.h"
  4. void Least_Squares(uint8_t n, float x[], uint32_t y[], float* slope, float* intercept)
  5. {
  6. float sumX = 0.0, sumY = 0.0, sumXY = 0.0, sumX2 = 0.0;
  7. // 计算各个累加和
  8. for (int i = 0; i < n; i++) {
  9. sumX += x[i];
  10. sumY += y[i];
  11. sumXY += x[i] * y[i];
  12. sumX2 += x[i] * x[i];
  13. }
  14. // 计算斜率和截距
  15. float denominator = n * sumX2 - sumX * sumX;
  16. *slope = (n * sumXY - sumX * sumY) / denominator;
  17. *intercept = (sumY - *slope * sumX) / n;
  18. }
  19. void buf2int(int *tint, unsigned char *buf)
  20. {
  21. int i;
  22. unsigned char * p1 = (unsigned char *)tint;
  23. unsigned char * p3 = buf;
  24. for (i = 0; i < 4; i++)
  25. {
  26. *p1 = *p3;
  27. p1++;
  28. p3++;
  29. }
  30. }
  31. float average(int n_values, ...)
  32. {
  33. va_list var_arg;
  34. int count;
  35. float sum = 0;
  36. /*** 准备访问可变参数 ***/
  37. va_start(var_arg, n_values);
  38. /*** 添加取自可变参数列表的值 ***/
  39. for (count = 0; count < n_values; count++)
  40. {
  41. sum += va_arg(var_arg, int);
  42. }
  43. /*** 完成处理可变参数 ***/
  44. va_end(var_arg);
  45. return sum / n_values;
  46. }
  47. #if 0
  48. /*位倒序*/
  49. uint8_t Bit_Reversed(uint8_t data)
  50. {
  51. uint8_t result = 0;
  52. for(uint8_t i = 0; i < 8; i++)
  53. {
  54. result = ((data >> i) & 0x01) | result;
  55. if(i < 7)
  56. {
  57. result = result << 1;
  58. }
  59. }
  60. return result;
  61. }
  62. void least_squares(uint8_t n, float x[], float y[], float* slope, float* intercept)
  63. {
  64. float sumX = 0.0, sumY = 0.0, sumXY = 0.0, sumX2 = 0.0;
  65. // 计算各个累加和
  66. for (int i = 0; i < n; i++) {
  67. sumX += x[i];
  68. sumY += y[i];
  69. sumXY += x[i] * y[i];
  70. sumX2 += x[i] * x[i];
  71. }
  72. // 计算斜率和截距
  73. float denominator = n * sumX2 - sumX * sumX;
  74. *slope = (n * sumXY - sumX * sumY) / denominator;
  75. *intercept = (sumY - *slope * sumX) / n;
  76. }
  77. #endif