int main() {
int n = 9;
double x[] = {-4, -3, -2, -1.5, -0.5, 1, 2, 3.5, 4};
double y[] = {-3, -1, -2, -0.5, 1, 0, 1.5, 1.0, 2.5};
double b1;
double b0;
lsqe(x, y, n, &b1, &b0);
printf("b1 = %f\nb0 = %f\n", b1, b0);
return 0;
}
int main(int argc, char **argv) {
double x[SIZE],
fx[SIZE],
z[SIZE],
pz[SIZE],
y[SIZE],
b1,
b0;
int retval,
i,
n;
/*****************************************************************************
* *
* Interpolate a function. *
* *
*****************************************************************************/
fprintf(stdout, "Perform polynomial interpolation\n");
x[0] = -3.0; fx[0] = -5.0;
x[1] = -2.0; fx[1] = -1.1;
x[2] = 2.0; fx[2] = 1.9;
x[3] = 3.0; fx[3] = 4.8;
z[0] = -2.5;
z[1] = -1.0;
z[2] = 0.0;
z[3] = 1.0;
z[4] = 1.5;
z[5] = 2.5;
if (interpol(x, fx, 4, z, pz, 6) != 0)
return 1;
fprintf(stdout, "Interpolating f(z) with p(z)\n");
for (i = 0; i < 4; i++)
fprintf(stdout, "x[%d]=%+1.6e, f(x[%d])=%+1.6e\n", i, x[i], i, fx[i]);
for (i = 0; i < 6; i++)
fprintf(stdout, "z[%d]=%+1.6e, p(z[%d])=%+1.6e\n", i, z[i], i, pz[i]);
x[0] = -4.0; fx[0] = -3.0;
x[1] = -3.5; fx[1] = 1.5;
x[2] = -2.5; fx[2] = 2.5;
x[3] = -1.5; fx[3] = 1.5;
x[4] = 0.0; fx[4] = 0.5;
x[5] = 1.5; fx[5] = 1.5;
x[6] = 2.5; fx[6] = 2.5;
x[7] = 3.5; fx[7] = 1.5;
x[8] = 4.0; fx[8] = -3.0;
z[0] = -0.50;
z[1] = -1.00;
z[2] = -2.00;
z[3] = -3.00;
z[4] = -3.25;
z[5] = -3.50;
z[6] = -3.75;
if (interpol(x, fx, 9, z, pz, 7) != 0)
return 1;
fprintf(stdout, "Interpolating f(z) with p(z)\n");
for (i = 0; i < 9; i++)
fprintf(stdout, "x[%d]=%+1.6e, f(x[%d])=%+1.6e\n", i, x[i], i, fx[i]);
for (i = 0; i < 7; i++)
fprintf(stdout, "z[%d]=%+1.6e, p(z[%d])=%+1.6e\n", i, z[i], i, pz[i]);
/*****************************************************************************
* *
* Compute least-squares estimators. *
* *
*****************************************************************************/
fprintf(stdout, "Perform least-squares estimation\n");
x[0] = 4.0; y[0] = 197.0;
x[1] = 6.0; y[1] = 272.0;
x[2] = 2.0; y[2] = 100.0;
x[3] = 5.0; y[3] = 228.0;
x[4] = 7.0; y[4] = 327.0;
x[5] = 6.0; y[5] = 279.0;
x[6] = 3.0; y[6] = 148.0;
x[7] = 8.0; y[7] = 377.0;
x[8] = 5.0; y[8] = 238.0;
x[9] = 3.0; y[9] = 142.0;
x[10] = 1.0; y[10] = 66.0;
x[11] = 5.0; y[11] = 239.0;
for (i = 0; i < 12; i++)
fprintf(stdout, "x[%02d]=%+1.6e, y[%02d]=%+1.6e\n", i, x[i], i, y[i]);
lsqe(x, y, 12, &b1, &b0);
fprintf(stdout, "b1=%+1.6e, b0=%+1.6e\n", b1, b0);
/*****************************************************************************
* *
* Find the roots of an equation. *
* *
*****************************************************************************/
fprintf(stdout, "Finding the roots of an equation\n");
n = 10;
x[0] = -2.0;
retval = root(f, g, x, &n, 0.0001);
for (i = 0; i < n; i++)
fprintf(stdout, "x[%d]=%+1.6e\n", i, x[i]);
if (retval != 0)
fprintf(stdout, "Did not find a root\n");
else
fprintf(stdout, "Found a root at %+1.6e\n", x[n - 1]);
n = 10;
x[0] = 0.5;
retval = root(f, g, x, &n, 0.0001);
for (i = 0; i < n; i++)
fprintf(stdout, "x[%d]=%+1.6e\n", i, x[i]);
if (retval != 0)
fprintf(stdout, "Did not find a root\n");
else
fprintf(stdout, "Found a root at %+1.6e\n", x[n - 1]);
n = 10;
x[0] = 2.0;
retval = root(f, g, x, &n, 0.0001);
for (i = 0; i < n; i++)
fprintf(stdout, "x[%d]=%+1.6e\n", i, x[i]);
if (retval != 0)
fprintf(stdout, "Did not find a root\n");
else
fprintf(stdout, "Found a root at %+1.6e\n", x[n - 1]);
return 0;
}