411 REFERENCE · Wikibooks
Linear Algebra and the C Language/a07n
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/* Save as : dpoly.h */
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void i_A_b_with_XY_mR(
double **XY,
double **A,
double **b
)
{
int r = R1;
int c = C1;
int power = 0;
for(r=R1; r<XY[R_SIZE][C0]; r++)
{
power=rsize_R(XY)-R1;
for(c=C1; c<A[C_SIZE][C0]; c++)
A[r][c]=pow(XY[r][C1],power--);
b[r][C1]=XY[r][C2];
}
}
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void p_eq_poly_mR(
double **Ab
)
{
int r = R1;
int power = rsize_R(Ab)-R1;
int cL = csize_R(Ab);
printf(" y = ");
for(r=R1;r<Ab[R_SIZE][C0];r++)
if(Ab[r][cL])
{
if(!power) printf(" %+.3f", Ab[r][cL]);
else if(power==1){printf(" %+.3fx", Ab[r][cL]);power--;}
else printf(" %+.3fx**%d",Ab[r][cL], power--);
}
else power--;
printf("\n\n\n");
}
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void verify_X_mR(
double **Ab,
double x
)
{
int r = R1;
int power = rsize_R(Ab)-R1;
int cL = csize_R(Ab);
double y = 0.;
for(;r<Ab[R_SIZE][C0];r++)
y+= Ab[r][cL]*pow(x,power--);
printf(" With x = %+.3f, y = %+.3f \n",x,y);
}
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