Linear Algebra and the C Language/a09w

__NOTOC__ Install and compile this file in your working directory. /* ------------------------------------ */ /* Save as: c00a.c */ /* ------------------------------------ */ #include "v_a.h" /* ------------------------------------ */ /* ------------------------------------ */ double **X_invgj_mR( double **A, double **invA ) { double **ID = i_RC_mR(A[R_SIZE][C0],A[C_SIZE][C0]); double **AID; int r = A[R_SIZE][C0]; r--; AID = i_Abr_Ac_bc_mR(r,r,r); eye_mR(ID); /* ID: Identity matrix */ c_A_b_Ab_mR(A,ID,AID); /* Copy A and ID into AID */ invgj_pivot_mR(AID); /* Work on the pivot */ sort_c_mR(AID); /* Sort the columns */ sort_r_mR(AID); /* Sort the rows */ c_Inv_A_mR(AID,invA); /* Copy the inverse into invA */ f_mR(AID); f_mR(ID); return(invA); } /* ------------------------------------ */ /* ------------------------------------ */ void fun(int r) { double **A = rE_mR( i_mR(r,r), 999.,1E-3); double **InvA = i_mR(r,r); clrscrn(); printf(" Copy/Paste into the octave window.\n\n"); printf("format short e\n"); p_Octave_mR(A,"A",P4); printf(" inv(A)\n\n"); printf(" See above for the function code: invgj_mR();\n\n InvA:"); X_invgj_mR(A,InvA); pE_mR(InvA, S12,P4,C6); f_mR(InvA); f_mR(A); } /* ------------------------------------ */ int main(void) { time_t t; srand(time(&t)); do { fun(C4); } while(stop_w()); return 0; } /* ------------------------------------ */ /* ------------------------------------ */ Screen output example: Copy/Paste into the octave window. format short e A=[ +0.8370,-0.0700,+0.5320,-0.7220; +0.6970,+0.4480,+0.8980,-0.3510; -0.2480,-0.1110,+0.6340,-0.2010; -0.1730,+0.2510,+0.3120,+0.6670] inv(A) See above for the function code: invgj_mR(); InvA: +1.6524e+00 -6.3813e-01 -1.0430e+00 +1.1386e+00 -2.7307e+00 +2.6376e+00 -5.8612e-01 -1.7444e+00 +5.4859e-01 -1.3496e-01 +9.1512e-01 +7.9858e-01 +1.1996e+00 -1.0949e+00 -4.7803e-01 +2.0775e+00 Press return to continue Press X return to stop