/** * Copyright (C) 2013 - present by OpenGamma Inc. and the OpenGamma group of companies * * Please see distribution for license. */ package com.opengamma.analytics.math.function; import java.io.Serializable; import com.opengamma.analytics.math.interpolation.PiecewisePolynomialResult2D; import com.opengamma.analytics.math.matrix.DoubleMatrix1D; import com.opengamma.analytics.math.matrix.DoubleMatrix2D; import com.opengamma.util.ArgumentChecker; /** * */ public class PiecewisePolynomialFunction2D implements Serializable { /** * Default constructor */ public PiecewisePolynomialFunction2D() { } /** * * @param pp PiecewisePolynomialResult2D * @param x0Key * @param x1Key * @return Value of piecewise polynomial function in 2D at (x0Key, x1Key) */ public double evaluate(final PiecewisePolynomialResult2D pp, final double x0Key, final double x1Key) { ArgumentChecker.notNull(pp, "pp"); ArgumentChecker.isFalse(Double.isNaN(x0Key), "x0Key containing NaN"); ArgumentChecker.isFalse(Double.isInfinite(x0Key), "x0Key containing Infinity"); ArgumentChecker.isFalse(Double.isNaN(x1Key), "x1Key containing NaN"); ArgumentChecker.isFalse(Double.isInfinite(x1Key), "x1Key containing Infinity"); final double[] knots0 = pp.getKnots0().getData(); final double[] knots1 = pp.getKnots1().getData(); final int nKnots0 = knots0.length; final int nKnots1 = knots1.length; int ind0 = 0; int ind1 = 0; for (int k = 1; k < nKnots0 - 1; ++k) { if (x0Key >= knots0[k]) { ind0 = k; } } for (int i = 1; i < nKnots1 - 1; ++i) { if (x1Key >= knots1[i]) { ind1 = i; } } final double res = getValue(pp.getCoefs()[ind0][ind1], x0Key, x1Key, knots0[ind0], knots1[ind1]); ArgumentChecker.isFalse(Double.isInfinite(res), "Too large input"); ArgumentChecker.isFalse(Double.isNaN(res), "Too large input"); return res; } /** * @param pp PiecewisePolynomialResult2D * @param x0Keys * @param x1Keys * @return Values of piecewise polynomial function in 2D at (x0Keys_i, x1Keys_j) */ public DoubleMatrix2D evaluate(final PiecewisePolynomialResult2D pp, final double[] x0Keys, final double[] x1Keys) { ArgumentChecker.notNull(pp, "pp"); ArgumentChecker.notNull(x0Keys, "x0Keys"); ArgumentChecker.notNull(x1Keys, "x1Keys"); final int n0Keys = x0Keys.length; final int n1Keys = x1Keys.length; for (int i = 0; i < n0Keys; ++i) { ArgumentChecker.isFalse(Double.isNaN(x0Keys[i]), "x0Keys containing NaN"); ArgumentChecker.isFalse(Double.isInfinite(x0Keys[i]), "x0Keys containing Infinity"); } for (int i = 0; i < n1Keys; ++i) { ArgumentChecker.isFalse(Double.isNaN(x1Keys[i]), "x1Keys containing NaN"); ArgumentChecker.isFalse(Double.isInfinite(x1Keys[i]), "x1Keys containing Infinity"); } final double[] knots0 = pp.getKnots0().getData(); final double[] knots1 = pp.getKnots1().getData(); final int nKnots0 = knots0.length; final int nKnots1 = knots1.length; double[][] res = new double[n0Keys][n1Keys]; for (int i = 0; i < n0Keys; ++i) { for (int j = 0; j < n1Keys; ++j) { int ind0 = 0; int ind1 = 0; for (int k = 1; k < nKnots0 - 1; ++k) { if (x0Keys[i] >= knots0[k]) { ind0 = k; } } for (int k = 1; k < nKnots1 - 1; ++k) { if (x1Keys[j] >= knots1[k]) { ind1 = k; } } res[i][j] = getValue(pp.getCoefs()[ind0][ind1], x0Keys[i], x1Keys[j], knots0[ind0], knots1[ind1]); ArgumentChecker.isFalse(Double.isInfinite(res[i][j]), "Too large input"); ArgumentChecker.isFalse(Double.isNaN(res[i][j]), "Too large input"); } } return new DoubleMatrix2D(res); } /** * @param pp PiecewisePolynomialResult2D * @param x0Key * @param x1Key * @return Value of first derivative of two-dimensional piecewise polynomial function with respect to x0 at (x0Keys_i, x1Keys_j) */ public double differentiateX0(final PiecewisePolynomialResult2D pp, final double x0Key, final double x1Key) { ArgumentChecker.notNull(pp, "pp"); final int order0 = pp.getOrder()[0]; final int order1 = pp.getOrder()[1]; ArgumentChecker.isFalse(order0 < 2, "polynomial degree of x0 < 1"); final DoubleMatrix1D knots0 = pp.getKnots0(); final DoubleMatrix1D knots1 = pp.getKnots1(); final int nKnots0 = knots0.getNumberOfElements(); final int nKnots1 = knots1.getNumberOfElements(); DoubleMatrix2D[][] coefs = pp.getCoefs(); DoubleMatrix2D[][] res = new DoubleMatrix2D[nKnots0][nKnots1]; for (int i = 0; i < nKnots0 - 1; ++i) { for (int j = 0; j < nKnots1 - 1; ++j) { double[][] matTmp = new double[order0 - 1][order1]; for (int k = 0; k < order0 - 1; ++k) { for (int l = 0; l < order1; ++l) { matTmp[k][l] = coefs[i][j].getData()[k][l] * (order0 - k - 1); } } res[i][j] = new DoubleMatrix2D(matTmp); } } PiecewisePolynomialResult2D ppDiff = new PiecewisePolynomialResult2D(knots0, knots1, res, new int[] {order0 - 1, order1 }); return evaluate(ppDiff, x0Key, x1Key); } /** * @param pp PiecewisePolynomialResult2D * @param x0Key * @param x1Key * @return Value of first derivative of two-dimensional piecewise polynomial function with respect to x1 at (x0Keys_i, x1Keys_j) */ public double differentiateX1(final PiecewisePolynomialResult2D pp, final double x0Key, final double x1Key) { ArgumentChecker.notNull(pp, "pp"); final int order0 = pp.getOrder()[0]; final int order1 = pp.getOrder()[1]; ArgumentChecker.isFalse(order1 < 2, "polynomial degree of x1 < 1"); final DoubleMatrix1D knots0 = pp.getKnots0(); final DoubleMatrix1D knots1 = pp.getKnots1(); final int nKnots0 = knots0.getNumberOfElements(); final int nKnots1 = knots1.getNumberOfElements(); DoubleMatrix2D[][] coefs = pp.getCoefs(); DoubleMatrix2D[][] res = new DoubleMatrix2D[nKnots0][nKnots1]; for (int i = 0; i < nKnots0 - 1; ++i) { for (int j = 0; j < nKnots1 - 1; ++j) { double[][] matTmp = new double[order0][order1 - 1]; for (int k = 0; k < order0; ++k) { for (int l = 0; l < order1 - 1; ++l) { matTmp[k][l] = coefs[i][j].getData()[k][l] * (order1 - l - 1); } } res[i][j] = new DoubleMatrix2D(matTmp); } } PiecewisePolynomialResult2D ppDiff = new PiecewisePolynomialResult2D(knots0, knots1, res, new int[] {order0, order1 - 1 }); return evaluate(ppDiff, x0Key, x1Key); } /** * @param pp PiecewisePolynomialResult2D * @param x0Keys * @param x1Keys * @return Values of first derivative of two-dimensional piecewise polynomial function with respect to x0 at (x0Keys_i, x1Keys_j) */ public DoubleMatrix2D differentiateX0(final PiecewisePolynomialResult2D pp, final double[] x0Keys, final double[] x1Keys) { ArgumentChecker.notNull(pp, "pp"); final int order0 = pp.getOrder()[0]; final int order1 = pp.getOrder()[1]; ArgumentChecker.isFalse(order0 < 2, "polynomial degree of x0 < 1"); final DoubleMatrix1D knots0 = pp.getKnots0(); final DoubleMatrix1D knots1 = pp.getKnots1(); final int nKnots0 = knots0.getNumberOfElements(); final int nKnots1 = knots1.getNumberOfElements(); DoubleMatrix2D[][] coefs = pp.getCoefs(); DoubleMatrix2D[][] res = new DoubleMatrix2D[nKnots0][nKnots1]; for (int i = 0; i < nKnots0 - 1; ++i) { for (int j = 0; j < nKnots1 - 1; ++j) { double[][] matTmp = new double[order0 - 1][order1]; for (int k = 0; k < order0 - 1; ++k) { for (int l = 0; l < order1; ++l) { matTmp[k][l] = coefs[i][j].getData()[k][l] * (order0 - k - 1); } } res[i][j] = new DoubleMatrix2D(matTmp); } } PiecewisePolynomialResult2D ppDiff = new PiecewisePolynomialResult2D(knots0, knots1, res, new int[] {order0 - 1, order1 }); return evaluate(ppDiff, x0Keys, x1Keys); } /** * @param pp PiecewisePolynomialResult2D * @param x0Keys * @param x1Keys * @return Values of first derivative of two-dimensional piecewise polynomial function with respect to x1 at (x0Keys_i, x1Keys_j) */ public DoubleMatrix2D differentiateX1(final PiecewisePolynomialResult2D pp, final double[] x0Keys, final double[] x1Keys) { ArgumentChecker.notNull(pp, "pp"); final int order0 = pp.getOrder()[0]; final int order1 = pp.getOrder()[1]; ArgumentChecker.isFalse(order1 < 2, "polynomial degree of x1 < 1"); final DoubleMatrix1D knots0 = pp.getKnots0(); final DoubleMatrix1D knots1 = pp.getKnots1(); final int nKnots0 = knots0.getNumberOfElements(); final int nKnots1 = knots1.getNumberOfElements(); DoubleMatrix2D[][] coefs = pp.getCoefs(); DoubleMatrix2D[][] res = new DoubleMatrix2D[nKnots0][nKnots1]; for (int i = 0; i < nKnots0 - 1; ++i) { for (int j = 0; j < nKnots1 - 1; ++j) { double[][] matTmp = new double[order0][order1 - 1]; for (int k = 0; k < order0; ++k) { for (int l = 0; l < order1 - 1; ++l) { matTmp[k][l] = coefs[i][j].getData()[k][l] * (order1 - l - 1); } } res[i][j] = new DoubleMatrix2D(matTmp); } } PiecewisePolynomialResult2D ppDiff = new PiecewisePolynomialResult2D(knots0, knots1, res, new int[] {order0, order1 - 1 }); return evaluate(ppDiff, x0Keys, x1Keys); } /** * @param pp PiecewisePolynomialResult2D * @param x0Key * @param x1Key * @return Value of cross derivative of two-dimensional piecewise polynomial function at (x0Keys_i, x1Keys_j) */ public double differentiateCross(final PiecewisePolynomialResult2D pp, final double x0Key, final double x1Key) { ArgumentChecker.notNull(pp, "pp"); final int order0 = pp.getOrder()[0]; final int order1 = pp.getOrder()[1]; ArgumentChecker.isFalse(order0 < 2, "polynomial degree of x0 < 1"); ArgumentChecker.isFalse(order1 < 2, "polynomial degree of x1 < 1"); final DoubleMatrix1D knots0 = pp.getKnots0(); final DoubleMatrix1D knots1 = pp.getKnots1(); final int nKnots0 = knots0.getNumberOfElements(); final int nKnots1 = knots1.getNumberOfElements(); DoubleMatrix2D[][] coefs = pp.getCoefs(); DoubleMatrix2D[][] res = new DoubleMatrix2D[nKnots0][nKnots1]; for (int i = 0; i < nKnots0 - 1; ++i) { for (int j = 0; j < nKnots1 - 1; ++j) { double[][] matTmp = new double[order0 - 1][order1 - 1]; for (int k = 0; k < order0 - 1; ++k) { for (int l = 0; l < order1 - 1; ++l) { matTmp[k][l] = coefs[i][j].getData()[k][l] * (order1 - l - 1) * (order0 - k - 1); } } res[i][j] = new DoubleMatrix2D(matTmp); } } PiecewisePolynomialResult2D ppDiff = new PiecewisePolynomialResult2D(knots0, knots1, res, new int[] {order0 - 1, order1 - 1 }); return evaluate(ppDiff, x0Key, x1Key); } /** * @param pp PiecewisePolynomialResult2D * @param x0Key * @param x1Key * @return Value of second derivative of two-dimensional piecewise polynomial function with respect to x0 at (x0Keys_i, x1Keys_j) */ public double differentiateTwiceX0(final PiecewisePolynomialResult2D pp, final double x0Key, final double x1Key) { ArgumentChecker.notNull(pp, "pp"); final int order0 = pp.getOrder()[0]; final int order1 = pp.getOrder()[1]; ArgumentChecker.isFalse(order0 < 3, "polynomial degree of x0 < 2"); final DoubleMatrix1D knots0 = pp.getKnots0(); final DoubleMatrix1D knots1 = pp.getKnots1(); final int nKnots0 = knots0.getNumberOfElements(); final int nKnots1 = knots1.getNumberOfElements(); DoubleMatrix2D[][] coefs = pp.getCoefs(); DoubleMatrix2D[][] res = new DoubleMatrix2D[nKnots0][nKnots1]; for (int i = 0; i < nKnots0 - 1; ++i) { for (int j = 0; j < nKnots1 - 1; ++j) { double[][] matTmp = new double[order0 - 2][order1]; for (int k = 0; k < order0 - 2; ++k) { for (int l = 0; l < order1; ++l) { matTmp[k][l] = coefs[i][j].getData()[k][l] * (order0 - k - 1) * (order0 - k - 2); } } res[i][j] = new DoubleMatrix2D(matTmp); } } PiecewisePolynomialResult2D ppDiff = new PiecewisePolynomialResult2D(knots0, knots1, res, new int[] {order0 - 2, order1 }); return evaluate(ppDiff, x0Key, x1Key); } /** * @param pp PiecewisePolynomialResult2D * @param x0Key * @param x1Key * @return Value of second derivative of two-dimensional piecewise polynomial function with respect to x1 at (x0Keys_i, x1Keys_j) */ public double differentiateTwiceX1(final PiecewisePolynomialResult2D pp, final double x0Key, final double x1Key) { ArgumentChecker.notNull(pp, "pp"); final int order0 = pp.getOrder()[0]; final int order1 = pp.getOrder()[1]; ArgumentChecker.isFalse(order1 < 3, "polynomial degree of x1 < 2"); final DoubleMatrix1D knots0 = pp.getKnots0(); final DoubleMatrix1D knots1 = pp.getKnots1(); final int nKnots0 = knots0.getNumberOfElements(); final int nKnots1 = knots1.getNumberOfElements(); DoubleMatrix2D[][] coefs = pp.getCoefs(); DoubleMatrix2D[][] res = new DoubleMatrix2D[nKnots0][nKnots1]; for (int i = 0; i < nKnots0 - 1; ++i) { for (int j = 0; j < nKnots1 - 1; ++j) { double[][] matTmp = new double[order0][order1 - 2]; for (int k = 0; k < order0; ++k) { for (int l = 0; l < order1 - 2; ++l) { matTmp[k][l] = coefs[i][j].getData()[k][l] * (order1 - l - 1) * (order1 - l - 2); } } res[i][j] = new DoubleMatrix2D(matTmp); } } PiecewisePolynomialResult2D ppDiff = new PiecewisePolynomialResult2D(knots0, knots1, res, new int[] {order0, order1 - 2 }); return evaluate(ppDiff, x0Key, x1Key); } /** * @param pp PiecewisePolynomialResult2D * @param x0Keys * @param x1Keys * @return Values of cross derivative of two-dimensional piecewise polynomial function at (x0Keys_i, x1Keys_j) */ public DoubleMatrix2D differentiateCross(final PiecewisePolynomialResult2D pp, final double[] x0Keys, final double[] x1Keys) { ArgumentChecker.notNull(pp, "pp"); final int order0 = pp.getOrder()[0]; final int order1 = pp.getOrder()[1]; ArgumentChecker.isFalse(order0 < 2, "polynomial degree of x0 < 1"); ArgumentChecker.isFalse(order1 < 2, "polynomial degree of x1 < 1"); final DoubleMatrix1D knots0 = pp.getKnots0(); final DoubleMatrix1D knots1 = pp.getKnots1(); final int nKnots0 = knots0.getNumberOfElements(); final int nKnots1 = knots1.getNumberOfElements(); DoubleMatrix2D[][] coefs = pp.getCoefs(); DoubleMatrix2D[][] res = new DoubleMatrix2D[nKnots0][nKnots1]; for (int i = 0; i < nKnots0 - 1; ++i) { for (int j = 0; j < nKnots1 - 1; ++j) { double[][] matTmp = new double[order0 - 1][order1 - 1]; for (int k = 0; k < order0 - 1; ++k) { for (int l = 0; l < order1 - 1; ++l) { matTmp[k][l] = coefs[i][j].getData()[k][l] * (order1 - l - 1) * (order0 - k - 1); } } res[i][j] = new DoubleMatrix2D(matTmp); } } PiecewisePolynomialResult2D ppDiff = new PiecewisePolynomialResult2D(knots0, knots1, res, new int[] {order0 - 1, order1 - 1 }); return evaluate(ppDiff, x0Keys, x1Keys); } /** * @param pp PiecewisePolynomialResult2D * @param x0Keys * @param x1Keys * @return Values of second derivative of two-dimensional piecewise polynomial function with respect to x0 at (x0Keys_i, x1Keys_j) */ public DoubleMatrix2D differentiateTwiceX0(final PiecewisePolynomialResult2D pp, final double[] x0Keys, final double[] x1Keys) { ArgumentChecker.notNull(pp, "pp"); final int order0 = pp.getOrder()[0]; final int order1 = pp.getOrder()[1]; ArgumentChecker.isFalse(order0 < 3, "polynomial degree of x0 < 2"); final DoubleMatrix1D knots0 = pp.getKnots0(); final DoubleMatrix1D knots1 = pp.getKnots1(); final int nKnots0 = knots0.getNumberOfElements(); final int nKnots1 = knots1.getNumberOfElements(); DoubleMatrix2D[][] coefs = pp.getCoefs(); DoubleMatrix2D[][] res = new DoubleMatrix2D[nKnots0][nKnots1]; for (int i = 0; i < nKnots0 - 1; ++i) { for (int j = 0; j < nKnots1 - 1; ++j) { double[][] matTmp = new double[order0 - 2][order1]; for (int k = 0; k < order0 - 2; ++k) { for (int l = 0; l < order1; ++l) { matTmp[k][l] = coefs[i][j].getData()[k][l] * (order0 - k - 1) * (order0 - k - 2); } } res[i][j] = new DoubleMatrix2D(matTmp); } } PiecewisePolynomialResult2D ppDiff = new PiecewisePolynomialResult2D(knots0, knots1, res, new int[] {order0 - 2, order1 }); return evaluate(ppDiff, x0Keys, x1Keys); } /** * @param pp PiecewisePolynomialResult2D * @param x0Keys * @param x1Keys * @return Values of second derivative of two-dimensional piecewise polynomial function with respect to x1 at (x0Keys_i, x1Keys_j) */ public DoubleMatrix2D differentiateTwiceX1(final PiecewisePolynomialResult2D pp, final double[] x0Keys, final double[] x1Keys) { ArgumentChecker.notNull(pp, "pp"); final int order0 = pp.getOrder()[0]; final int order1 = pp.getOrder()[1]; ArgumentChecker.isFalse(order1 < 3, "polynomial degree of x1 < 2"); final DoubleMatrix1D knots0 = pp.getKnots0(); final DoubleMatrix1D knots1 = pp.getKnots1(); final int nKnots0 = knots0.getNumberOfElements(); final int nKnots1 = knots1.getNumberOfElements(); DoubleMatrix2D[][] coefs = pp.getCoefs(); DoubleMatrix2D[][] res = new DoubleMatrix2D[nKnots0][nKnots1]; for (int i = 0; i < nKnots0 - 1; ++i) { for (int j = 0; j < nKnots1 - 1; ++j) { double[][] matTmp = new double[order0][order1 - 2]; for (int k = 0; k < order0; ++k) { for (int l = 0; l < order1 - 2; ++l) { matTmp[k][l] = coefs[i][j].getData()[k][l] * (order1 - l - 1) * (order1 - l - 2); } } res[i][j] = new DoubleMatrix2D(matTmp); } } PiecewisePolynomialResult2D ppDiff = new PiecewisePolynomialResult2D(knots0, knots1, res, new int[] {order0, order1 - 2 }); return evaluate(ppDiff, x0Keys, x1Keys); } /** * @param coefMat * @param x0 * @param x1 * @param leftKnot0 * @param leftKnot1 * @return sum_{i=0}^{order0-1} sum_{j=0}^{order1-1} coefMat_{ij} (x0-leftKnots0)^{order0-1-i} (x1-leftKnots1)^{order0-1-j} */ private double getValue(final DoubleMatrix2D coefMat, final double x0, final double x1, final double leftKnot0, final double leftKnot1) { final int order0 = coefMat.getNumberOfRows(); final int order1 = coefMat.getNumberOfColumns(); final double x0Mod = x0 - leftKnot0; final double x1Mod = x1 - leftKnot1; double res = 0.; for (int i = 0; i < order0; ++i) { for (int j = 0; j < order1; ++j) { res += coefMat.getData()[order0 - i - 1][order1 - j - 1] * Math.pow(x0Mod, i) * Math.pow(x1Mod, j); } } return res; } }