【C言語】LAPACKを使った多変数の最小二乗法の計算方法【Cygwin】
Cygwinを用いて、多変数の最小二乗法を行ったので、備忘録として、下記に留める。
となるを求めるプログラム。(今回は5次まで)
の順でスペースで区切られた近似したいデータファイル(test.dat)を読み込んで計算します。
gcc sample.c -llapack -lblas -lm のコマンドでコンパイルします。
#include <stdio.h> #include <stdlib.h> #include <math.h> int dim,dim1,dim2,dim3; void matrix_transposition(int,int,double **A,double **t_A);//行列転置 void matrix_initialize(int,int,double **A); //行列要素すべて0 void matrix_inverse(int,double **A,double **B); void matrix_inverse2(int,double **A,double **B); void matrix_calculate(int,int,int, double **A,double **B,double **C); double g_calc(int,double T,double omega); void test_printf(int,int,double **A,char *);//テスト用表示 #define SIZE 21 #define NSIZE 30 int main(void){ int i,j; FILE *fp; int ret; int cnt = 0; char fname[100] = "test.dat"; //printf("filename="); //scanf("%s",&fname); fp = fopen( fname , "r" ); if( fp == NULL ){ printf( "%sファイルが開けません\n", fname ); return -1; } while((ret = getc(fp)) != EOF) { if(ret == '\n') cnt++; } //int NSIZE = cnt; printf("NSIZE = %d\n",NSIZE); static double S_total,S[NSIZE],SI[NSIZE],sigma,rS[SIZE]; double **G; G = malloc(sizeof(double *) * SIZE); for (i=0;i<SIZE;i++) { G[i] = malloc(sizeof(double) * NSIZE); } double **t_G; t_G = malloc(sizeof(double *) * NSIZE); for (i=0;i<NSIZE;i++) { t_G[i] = malloc(sizeof(double) * SIZE); } double **temp; temp = malloc(sizeof(double *) * SIZE); for (i=0;i<SIZE;i++) { temp[i] = malloc(sizeof(double) * SIZE); } double **i_temp; i_temp = malloc(sizeof(double *) * SIZE); for (i=0;i<SIZE;i++) { i_temp[i] = malloc(sizeof(double) * SIZE); } double **temp2; temp2 = malloc(sizeof(double *) * SIZE); for (i=0;i<SIZE;i++) { temp2[i] = malloc(sizeof(double) * 1); } double **I; I = malloc(sizeof(double *) * NSIZE); for (i=0;i<NSIZE;i++) { I[i] = malloc(sizeof(double) * 1); } double *T; T = malloc(sizeof(double ) * NSIZE); double *omega; omega = malloc(sizeof(double ) * NSIZE); double **a; a = malloc(sizeof(double *) * SIZE); for (i=0;i<SIZE;i++) { a[i] = malloc(sizeof(double) * 1); } double **unit; unit = malloc(sizeof(double *) * SIZE); for (i=0;i<SIZE;i++) { unit[i] = malloc(sizeof(double) * SIZE); } rewind( fp ); for(i=0;i<NSIZE;i++){ ret = fscanf( fp, "%lf %lf %lf", &I[i][0],&T[i],&omega[i]) ; //T[i] = T[i]; //omega[i] = omega[i]; //printf("%e %e %e\n",I[i][0],T[i],omega[i]); } fclose(fp); for(i=0;i<SIZE;i++){ for(j=0;j<NSIZE;j++){ G[i][j] = g_calc(i,T[j],omega[j]); //printf("G[%d][%d] =%e\n",i,j,G[i][j]); } } //test_printf(SIZE,NSIZE,G,"G"); matrix_transposition(SIZE,NSIZE,G,t_G); //test_printf(SIZE,NSIZE,t_G,"t_G"); matrix_calculate(SIZE,NSIZE,SIZE,G,t_G,temp); test_printf(SIZE,SIZE,temp,"temp"); matrix_inverse(SIZE,temp,i_temp); //matrix_calculate(SIZE,SIZE,SIZE,i_temp,temp,unit); //test_printf(SIZE,SIZE,unit,"unit"); //puts("pass3"); matrix_calculate(SIZE,NSIZE,1,G,I,temp2); //test_printf(SIZE,SIZE,i_temp,"i_temp"); //test_printf(SIZE,SIZE,i_temp,"i_temp"); matrix_calculate(SIZE,SIZE,1,i_temp,temp2,a); for(i=0;i<SIZE;i++){ printf("a[%d] = %e\n",i,a[i][0]); } for(j=0;j<NSIZE;j++){ SI[j]=0.; for(i=0;i<SIZE;i++){ SI[j] += a[i][0]* g_calc(i,T[j],omega[j]); } S[j] = (I[j][0] - SI[j])*(I[j][0] - SI[j])/((double) NSIZE); rS[j] = sqrt(S[j]*((double) NSIZE)); printf("%e\n",rS[j]); } S_total = 0.; for(j=0;j<NSIZE;j++){ S_total += S[j]; } sigma = sqrt(S_total); printf("standard deviation = %e",sigma); free( G ); free( t_G ); free( temp ); free( i_temp ); free( temp2 ); free( I ); free( T ); free( omega ); free( a ); } double g_calc(int i,double T,double omega){ double ans; switch (i) { case 0: ans =1.0; return ans; break; case 1: ans = T; return ans; break; case 2: ans = omega; return ans; break; case 3: ans =T*T; return ans; break; case 4: ans =T*omega; return ans; break; case 5: ans =omega*omega; return ans; break; case 6: ans = T*T*T; return ans; break; case 7: ans = T*T*omega; return ans; break; case 8: ans = T*omega*omega; return ans; break; case 9: ans =omega*omega*omega; return ans; break; case 10: ans =T*T*T*T; return ans; break; case 11: ans = T*T*T*omega; return ans; break; case 12: ans = T*T*omega*omega; return ans; break; case 13: ans = T*omega*omega*omega; return ans; break; case 14: ans =omega*omega*omega*omega; return ans; break; case 15: ans =T*T*T*T*T; return ans; break; case 16: ans = T*T*T*T*omega; return ans; break; case 17: ans = T*T*T*omega*omega; return ans; break; case 18: ans = T*T*omega*omega*omega; return ans; break; case 19: ans =T*omega*omega*omega*omega; return ans; break; case 20: ans =omega*omega*omega*omega*omega; return ans; break; default: break; } } void matrix_calculate(int dim1,int dim2,int dim3, double **A,double **B,double **C){ int i,j,k; matrix_initialize(dim1,dim3,C); for(i=0;i<dim1;i++){ for(j=0;j<dim3;j++){ for(k=0;k<dim2;k++){ C[i][j]=C[i][j]+A[i][k]*B[k][j]; } } } } void matrix_inverse2(int dim,double **A,double **B){ double buf; //一時的なデータを蓄える int i,j,k; //カウンタ int n=dim; //配列の次数 double inv_a[dim][dim]; double C[dim][dim]; for(i=0;i<n;i++){ for(j=0;j<n;j++){ C[i][j]= A[i][j]; } } //単位行列を作る for(i=0;i<n;i++){ for(j=0;j<n;j++){ if(i==j){ B[i][j]=1.0;} else{B[i][j] = 0.0;} } } //掃き出し法 for(i=0;i<n;i++){ buf=1/C[i][i]; for(j=0;j<n;j++){ C[i][j]*=buf; B[i][j]*=buf; } for(j=0;j<n;j++){ if(i!=j){ buf=C[j][i]; for(k=0;k<n;k++){ C[j][k]-=C[i][k]*buf; B[j][k]-=B[i][k]*buf; } } } } } void matrix_inverse(int dim,double **A,double **B){ int i,j; long m = dim ; // 行のサイズ long n = dim ; // 列のサイズ long lda = dim ; // mと同じ値 double *C; C = malloc(sizeof(double) * dim); for(i=0;i<dim;i++){ for(j=0;j<dim;j++){ C[dim*i+j] = A[i][j]; } } //test_printf(dim,dim,B,"B"); long info ; long ipiv[dim] ; long lwork = dim ; double work[dim] ; dgetrf_( &m, &n, C, &lda, ipiv, &info); if(info !=0){puts("error_LU");} dgetri_( &n, C, &lda, ipiv, work, &lwork, &info); if(info !=0){puts("error_inverse");} for(i=0;i<dim;i++){ for(j=0;j<dim;j++){ B[i][j] = C[dim*i+j]; } } } //行列要素すべて0 void matrix_initialize(int dim1,int dim2,double **A){ int i,j; for(i=0;i<dim1;i++){ for(j=0;j<dim2;j++){ A[i][j]=0.0; } } } //行列転置 void matrix_transposition(int dim1,int dim2,double **A,double **t_A){ int i,j; for(i=0;i<dim1;i++){ for(j=0;j<dim2;j++){ t_A[j][i]=A[i][j]; } } } //テスト用表示 void test_printf(int dim1,int dim2,double **A,char *name){ int i,j; for(i=0;i<dim1;i++){ for(j=0;j<dim2;j++){ printf("%s[%d,%d] = %e \n",name,i,j,A[i][j]); } } printf("\n"); }