public static DoubleMatrix polyval(
final DoubleMatrix x, final DoubleMatrix y, final DoubleMatrix coeff, int degree) {
if (!x.isColumnVector()) {
logger.warn("polyValGrid: require (x) standing data vectors!");
throw new IllegalArgumentException("polyval functions require (x) standing data vectors!");
}
if (!y.isColumnVector()) {
logger.warn("polyValGrid: require (y) standing data vectors!");
throw new IllegalArgumentException("polyval functions require (y) standing data vectors!");
}
if (!coeff.isColumnVector()) {
logger.warn("polyValGrid: require (coeff) standing data vectors!");
throw new IllegalArgumentException(
"polyval functions require (coeff) standing data vectors!");
}
if (degree < -1) {
logger.warn("polyValGrid: degree < -1 ????");
}
if (x.length > y.length) {
logger.warn("polValGrid: x larger than y, while optimized for y larger x");
}
if (degree == -1) {
degree = degreeFromCoefficients(coeff.length);
}
// evaluate polynomial //
DoubleMatrix result = new DoubleMatrix(x.length, y.length);
int i;
int j;
double c00,
c10,
c01,
c20,
c11,
c02,
c30,
c21,
c12,
c03,
c40,
c31,
c22,
c13,
c04,
c50,
c41,
c32,
c23,
c14,
c05;
switch (degree) {
case 0:
result.put(0, 0, coeff.get(0, 0));
break;
case 1:
c00 = coeff.get(0, 0);
c10 = coeff.get(1, 0);
c01 = coeff.get(2, 0);
for (j = 0; j < result.columns; j++) {
double c00pc01y1 = c00 + c01 * y.get(j, 0);
for (i = 0; i < result.rows; i++) {
result.put(i, j, c00pc01y1 + c10 * x.get(i, 0));
}
}
break;
case 2:
c00 = coeff.get(0, 0);
c10 = coeff.get(1, 0);
c01 = coeff.get(2, 0);
c20 = coeff.get(3, 0);
c11 = coeff.get(4, 0);
c02 = coeff.get(5, 0);
for (j = 0; j < result.columns; j++) {
double y1 = y.get(j, 0);
double c00pc01y1 = c00 + c01 * y1;
double c02y2 = c02 * Math.pow(y1, 2);
double c11y1 = c11 * y1;
for (i = 0; i < result.rows; i++) {
double x1 = x.get(i, 0);
result.put(i, j, c00pc01y1 + c10 * x1 + c20 * Math.pow(x1, 2) + c11y1 * x1 + c02y2);
}
}
break;
case 3:
c00 = coeff.get(0, 0);
c10 = coeff.get(1, 0);
c01 = coeff.get(2, 0);
c20 = coeff.get(3, 0);
c11 = coeff.get(4, 0);
c02 = coeff.get(5, 0);
c30 = coeff.get(6, 0);
c21 = coeff.get(7, 0);
c12 = coeff.get(8, 0);
c03 = coeff.get(9, 0);
for (j = 0; j < result.columns; j++) {
double y1 = y.get(j, 0);
double y2 = Math.pow(y1, 2);
double c00pc01y1 = c00 + c01 * y1;
double c02y2 = c02 * y2;
double c11y1 = c11 * y1;
double c21y1 = c21 * y1;
double c12y2 = c12 * y2;
double c03y3 = c03 * y1 * y2;
for (i = 0; i < result.rows; i++) {
double x1 = x.get(i, 0);
double x2 = Math.pow(x1, 2);
result.put(
i,
j,
c00pc01y1
+ c10 * x1
+ c20 * x2
+ c11y1 * x1
+ c02y2
+ c30 * x1 * x2
+ c21y1 * x2
+ c12y2 * x1
+ c03y3);
}
}
break;
case 4:
c00 = coeff.get(0, 0);
c10 = coeff.get(1, 0);
c01 = coeff.get(2, 0);
c20 = coeff.get(3, 0);
c11 = coeff.get(4, 0);
c02 = coeff.get(5, 0);
c30 = coeff.get(6, 0);
c21 = coeff.get(7, 0);
c12 = coeff.get(8, 0);
c03 = coeff.get(9, 0);
c40 = coeff.get(10, 0);
c31 = coeff.get(11, 0);
c22 = coeff.get(12, 0);
c13 = coeff.get(13, 0);
c04 = coeff.get(14, 0);
for (j = 0; j < result.columns; j++) {
double y1 = y.get(j, 0);
double y2 = Math.pow(y1, 2);
double c00pc01y1 = c00 + c01 * y1;
double c02y2 = c02 * y2;
double c11y1 = c11 * y1;
double c21y1 = c21 * y1;
double c12y2 = c12 * y2;
double c03y3 = c03 * y1 * y2;
double c31y1 = c31 * y1;
double c22y2 = c22 * y2;
double c13y3 = c13 * y2 * y1;
double c04y4 = c04 * y2 * y2;
for (i = 0; i < result.rows; i++) {
double x1 = x.get(i, 0);
double x2 = Math.pow(x1, 2);
result.put(
i,
j,
c00pc01y1
+ c10 * x1
+ c20 * x2
+ c11y1 * x1
+ c02y2
+ c30 * x1 * x2
+ c21y1 * x2
+ c12y2 * x1
+ c03y3
+ c40 * x2 * x2
+ c31y1 * x2 * x1
+ c22y2 * x2
+ c13y3 * x1
+ c04y4);
}
}
break;
case 5:
c00 = coeff.get(0, 0);
c10 = coeff.get(1, 0);
c01 = coeff.get(2, 0);
c20 = coeff.get(3, 0);
c11 = coeff.get(4, 0);
c02 = coeff.get(5, 0);
c30 = coeff.get(6, 0);
c21 = coeff.get(7, 0);
c12 = coeff.get(8, 0);
c03 = coeff.get(9, 0);
c40 = coeff.get(10, 0);
c31 = coeff.get(11, 0);
c22 = coeff.get(12, 0);
c13 = coeff.get(13, 0);
c04 = coeff.get(14, 0);
c50 = coeff.get(15, 0);
c41 = coeff.get(16, 0);
c32 = coeff.get(17, 0);
c23 = coeff.get(18, 0);
c14 = coeff.get(19, 0);
c05 = coeff.get(20, 0);
for (j = 0; j < result.columns; j++) {
double y1 = y.get(j, 0);
double y2 = Math.pow(y1, 2);
double y3 = y2 * y1;
double c00pc01y1 = c00 + c01 * y1;
double c02y2 = c02 * y2;
double c11y1 = c11 * y1;
double c21y1 = c21 * y1;
double c12y2 = c12 * y2;
double c03y3 = c03 * y3;
double c31y1 = c31 * y1;
double c22y2 = c22 * y2;
double c13y3 = c13 * y3;
double c04y4 = c04 * y2 * y2;
double c41y1 = c41 * y1;
double c32y2 = c32 * y2;
double c23y3 = c23 * y3;
double c14y4 = c14 * y2 * y2;
double c05y5 = c05 * y3 * y2;
for (i = 0; i < result.rows; i++) {
double x1 = x.get(i, 0);
double x2 = Math.pow(x1, 2);
double x3 = x1 * x2;
result.put(
i,
j,
c00pc01y1
+ c10 * x1
+ c20 * x2
+ c11y1 * x1
+ c02y2
+ c30 * x3
+ c21y1 * x2
+ c12y2 * x1
+ c03y3
+ c40 * x2 * x2
+ c31y1 * x3
+ c22y2 * x2
+ c13y3 * x1
+ c04y4
+ c50 * x3 * x2
+ c41y1 * x2 * x2
+ c32y2 * x3
+ c23y3 * x2
+ c14y4 * x1
+ c05y5);
}
}
break;
// TODO: solve up to 5 efficiently, do rest in loop
default:
for (j = 0; j < result.columns; j++) {
double yy = y.get(j, 0);
for (i = 0; i < result.rows; i++) {
double xx = x.get(i, 0);
result.put(i, j, polyval(xx, yy, coeff, degree));
}
}
} // switch degree
return result;
}
