411 REFERENCE · Wikibooks
Linear Algebra and the C Language/a02d
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
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/* ------------------------------------ */
/* Save as : vgjinv.h */
/* ------------------------------------ */
double **invgj_pivot_mR(
double **Ab
)
{
double pivot = 1.;
int r= R1;
while( pivot &&
(r<Ab[R_SIZE ][C0])
)
{
pivot = pivotbestAId_mR(Ab,r);
if(pivot>ERROR_E)
zero_under_pivot_gj1Ab_mR(Ab,r);
r++;
}
while( (r>R1) )
{
r--;
zero_above_pivot_gj1Ab_mR(Ab,r);
}
return(Ab);
}
/* ------------------------------------ */
double **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);
c_A_b_Ab_mR(A,ID,AID);
invgj_pivot_mR(AID);
sort_c_mR(AID);
sort_r_mR(AID);
c_Inv_A_mR(AID,invA);
f_mR(AID);
f_mR(ID);
return(invA);
}
/* ------------------------------------ */
/* ------------------------------------ */