ne10_result_t ne10_detmat_2x2f_c (ne10_float32_t * dst, ne10_mat2x2f_t * src, ne10_uint32_t count)
{
NE10_CHECKPOINTER_DstSrc;
for ( unsigned int itr = 0; itr < count; itr++ )
{
dst[ itr ] = DET2x2 (&src[ itr ]);
}
return NE10_OK;
}
double interp1d (double x, double wl[], double f[], int n, int *starti) {
/* arguments:
double x i: the value at which the function is to be evaluated
double wl[] i: the array of independent variable values
double f[] i: the array of dependent variable values
int n i: size of wl and f arrays
int *starti io: begin here for finding nearest wl to x
*/
double p0, p1, p2, p3; /* differences between x and wl elements */
double f0, f1, f2, f3; /* nearest elements in f array */
double wl0, wl1, wl2, wl3; /* nearest elements in wl array */
double temp1, temp2, temp3;
double temp12, temp13;
double y; /* interpolated value */
int i; /* index for which wl[i] is closest to x */
if (n == 1 || x <= wl[0]) {
y = f[0];
} else if (x >= wl[n-1]) {
y = f[n-1];
} else if (n == 2) {
p0 = (wl[1] - x) / (wl[1] - wl[0]);
p1 = 1. - x;
y = f[0] * p0 + f[1] * p1;
} else if (n == 3) {
p0 = wl[0] - x;
p1 = wl[1] - x;
p2 = wl[2] - x;
y = ((f[0] * p1 - f[1] * p0) * p2 / (wl[1] - wl[0]) -
(f[0] * p2 - f[2] * p0) * p1 / (wl[2] - wl[0])) /
(wl[2] - wl[1]);
} else {
/* Find the index i such that x is between wl[i] and wl[i+1].
We want i and i+1 to be the middle elements of a set of four,
so we limit i to the range from one through n-3 inclusive.
*/
i = *starti;
if (i < 1 || i > n-3 || /* i is out of range? */
x < wl[i-1] || x > wl[i+2]) { /* i is not close? */
i = BinarySearch (x, wl, n);
} else {
/* starting value is close, so check nearby points */
if (wl[i-1] <= x && x < wl[i]) {
if (i > 1) {
i--;
}
} else if (wl[i+1] <= x && x <= wl[i+2]) {
if (i < n - 3) {
i++;
}
}
}
*starti = i; /* update the starting location */
wl0 = wl[i-1];
wl1 = wl[i];
wl2 = wl[i+1];
wl3 = wl[i+2];
f0 = f[i-1];
f1 = f[i];
f2 = f[i+1];
f3 = f[i+2];
p0 = wl0 - x;
p1 = wl1 - x;
p2 = wl2 - x;
p3 = wl3 - x;
temp1 = DET2x2 (f0, p0,
f1, p1) / (wl1 - wl0);
temp2 = DET2x2 (f0, p0,
f2, p2) / (wl2 - wl0);
temp3 = DET2x2 (f0, p0,
f3, p3) / (wl3 - wl0);
temp12 = DET2x2 (temp1, p1,
temp2, p2) / (wl2 - wl1);
temp13 = DET2x2 (temp1, p1,
temp3, p3) / (wl3 - wl1);
y = DET2x2 (temp12, p2,
temp13, p3) / (wl3 - wl2);
}
return (y);
}
