Linear Algebra and the C Language/a09x

__NOTOC__ Install and compile this file in your working directory. /* ------------------------------------ */ /* Save as : c00a.c */ /* ------------------------------------ */ #include "v_a.h" /* ------------------------------------ */ #define Cb C1 /* ------------------------------------ */ void fun(int r) { double **A = r_mR( i_mR(r,r ),999); double **B = r_mR( i_mR(r,Cb),999); double **InvA = invgj_mR(A, i_mR(r,r)); double **X = mul_mR(InvA,B, i_mR(r,Cb)) ; double **T = mul_mR(A,X, i_mR(r,Cb)) ; clrscrn(); printf(" We want to find X such as, \n\n"); printf(" AX = B \n\n"); printf(" If A is a square matrix and, \n\n"); printf(" If A has an inverse matrix, \n\n"); printf(" you can find X by this method\n\n"); printf(" X = inv(A) B \n\n\n"); printf(" To verify the result you can \n\n"); printf(" multiply the matrix A by X. \n\n"); printf(" You must refind B. \n\n"); stop(); clrscrn(); printf(" A:"); p_mR(A,S5,P0,C7); printf(" B:"); p_mR(B,S5,P0,C7); stop(); clrscrn(); printf(" InvA:"); pE_mR(InvA,S1,P3,C7); printf(" X = InvA B:"); p_mR(X,S13,P4,C7); stop(); clrscrn(); printf(" B:"); p_mR(B,S5,P0,C7); printf(" AX:"); p_mR(T,S5,P0,C7); f_mR(T); f_mR(X); f_mR(B); f_mR(InvA); f_mR(A); } /* ------------------------------------ */ int main(void) { time_t t; srand(time(&t)); do { fun(rp_I(C2)+C4); } while(stop_w()); return 0; } /* ------------------------------------ */ /* ------------------------------------ */ Screen output example: We want to find X such as, AX = B If A is a square matrix and, If A has an inverse matrix, you can find X by this method X = inv(A) B To verify the result you can multiply the matrix A by X. You must refind B. A : +311 +927 +224 -208 -261 +906 -624 -417 +261 +91 +83 +955 +721 +767 -585 +840 +628 -226 +379 -2 +998 +169 -373 +968 -845 B : -534 +773 -19 -165 -157 inv(A) : +8.492e-04 +1.361e-03 +2.837e-04 -2.492e-04 -3.116e-04 +9.374e-06 -9.298e-04 -2.145e-04 +9.692e-04 +4.318e-05 +6.680e-04 +1.687e-03 +1.329e-03 -1.078e-03 -9.425e-04 -1.505e-03 -4.684e-04 +5.209e-04 +9.497e-04 +5.147e-05 -1.014e-03 +1.398e-04 +3.021e-04 +1.463e-03 -1.068e-03 X = inv(A) * B : +0.6829 -0.8864 +1.2477 +0.2667 +0.5699 B : -534 +773 -19 -165 -157 AX : -534 +773 -19 -165 -157 Press return to continue Press X return to stop