# include # include # include # include # include using namespace std; # include "hermite_cubic.hpp" //****************************************************************************80 double hermite_cubic_integral ( double x1, double f1, double d1, double x2, double f2, double d2 ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_INTEGRAL returns the integral of a Hermite cubic polynomial. // // Discussion: // // The integral is taken over the definition interval [X1,X2]. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 12 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, double X1, F1, D1, the left endpoint, function value // and derivative. // // Input, double X2, F2, D2, the right endpoint, function value // and derivative. // // Output, double HERMITE_CUBIC_INTEGRAL, the integral of the Hermite // cubic polynomial over the interval X1 <= X <= X2. // { double h; double q; h = x2 - x1; q = 0.5 * h * ( f1 + f2 + h * ( d1 - d2 ) / 6.0 ); return q; } //****************************************************************************80 double hermite_cubic_integrate ( double x1, double f1, double d1, double x2, double f2, double d2, double a, double b ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_INTEGRATE integrates a Hermite cubic polynomial from A to B. // // Discussion: // // A and B may be scalars, or one may be a vector, or both // may be vectors of the same size. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 12 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, double X1, F1, D1, the left endpoint, function value // and derivative. // // Input, double X2, F2, D2, the right endpoint, function value // and derivative. // // Input, double A, B, the left and right endpoints of the interval // of integration. // // Output, double HERMITE_CUBIC_INTEGRATE, the integral of the // Hermite cubic polynomial over the interval A <= X <= B. // { double dterm; double fterm; double h; double phia1; double phia2; double phib1; double phib2; double psia1; double psia2; double psib1; double psib2; double q; double ta1; double ta2; double tb1; double tb2; double ua1; double ua2; double ub1; double ub2; h = x2 - x1; ta1 = ( a - x1 ) / h; ta2 = ( x2 - a ) / h; tb1 = ( b - x1 ) / h; tb2 = ( x2 - b ) / h; ua1 = ta1 * ta1 * ta1; phia1 = ua1 * ( 2.0 - ta1 ); psia1 = ua1 * ( 3.0 * ta1 - 4.0 ); ua2 = ta2 * ta2 * ta2; phia2 = ua2 * ( 2.0 - ta2 ); psia2 = -ua2 * ( 3.0 * ta2 - 4.0 ); ub1 = tb1 * tb1 * tb1; phib1 = ub1 * ( 2.0 - tb1 ); psib1 = ub1 * ( 3.0 * tb1 - 4.0 ); ub2 = tb2 * tb2 * tb2; phib2 = ub2 * ( 2.0 - tb2 ); psib2 = -ub2 * ( 3.0 * tb2 - 4.0 ); fterm = f1 * ( phia2 - phib2 ) + f2 * ( phib1 - phia1 ); dterm = ( d1 * ( psia2 - psib2 ) + d2 * ( psib1 - psia1 ) ) * ( h / 6.0 ); q = 0.5 * h * ( fterm + dterm ); return q; } //****************************************************************************80 double *hermite_cubic_lagrange_integral ( double x1, double x2 ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_LAGRANGE_INTEGRAL: Hermite cubic Lagrange integrals. // // Discussion: // // The Hermite cubic polynomial P(X) for interval (X1,X2) and data // (F1,D1,F2,D2) satisfies: // // P(X1) = F1, // P'(X1) = D1, // P(X2) = F2, // P'(X2) = D2. // // We can determine four Lagrange polynomials L1(X) through L4(X) so that // // P(X) = F1 * L1(X) + D1 * L2(X) + F2 * L3(X) + D2 * L4(X). // // This function returns the integrals of these four polynomials over // the domain of definition [X1,X2]. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 15 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, double X1, X2, the endpoints. // // Output, double HERMITE_CUBIC_LAGRANGE_INTEGRAL[4], the integrals of the // Hermite cubic Lagrange polynomials from X1 to X2. // { double h; double *q; q = new double[4]; h = x2 - x1; q[0] = h / 2.0; q[1] = h * h / 12.0; q[2] = h / 2.0; q[3] = - h * h / 12.0; return q; } //****************************************************************************80 double *hermite_cubic_lagrange_integrate ( double x1, double x2, double a, double b ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_LAGRANGE_INTEGRATE integrates Hermite cubic Lagrange polynomials. // // Discussion: // // A and B may be scalars, or one may be a vector, or both // may be vectors of the same size. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 15 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, double X1, X2, the endpoints of the interval of definition. // // Input, double A, B, the left and right endpoints of the interval // of integration. // // Output, double HERMITE_CUBIC_LAGRANGE_INTEGRATE[4], the integrals of the // Hermite cubic Lagrange polynomials over the interval A <= X <= B. // { double h; double phia1; double phia2; double phib1; double phib2; double psia1; double psia2; double psib1; double psib2; double *q; double ta1; double ta2; double tb1; double tb2; double ua1; double ua2; double ub1; double ub2; h = x2 - x1; ta1 = ( a - x1 ) / h; ta2 = ( x2 - a ) / h; tb1 = ( b - x1 ) / h; tb2 = ( x2 - b ) / h; ua1 = ta1 * ta1 * ta1; phia1 = ua1 * ( 2.0 - ta1 ); psia1 = ua1 * ( 3.0 * ta1 - 4.0 ); ua2 = ta2 * ta2 * ta2; phia2 = ua2 * ( 2.0 - ta2 ); psia2 = -ua2 * ( 3.0 * ta2 - 4.0 ); ub1 = tb1 * tb1 * tb1; phib1 = ub1 * ( 2.0 - tb1 ); psib1 = ub1 * ( 3.0 * tb1 - 4.0 ); ub2 = tb2 * tb2 * tb2; phib2 = ub2 * ( 2.0 - tb2 ); psib2 = -ub2 * ( 3.0 * tb2 - 4.0 ); q = new double[4]; q[0] = 0.5 * h * ( phia2 - phib2 ); q[1] = 0.5 * h * ( psia2 - psib2 ) * ( h / 6.0 ); q[2] = 0.5 * h * ( phib1 - phia1 ); q[3] = 0.5 * h * ( psib1 - psia1 ) * ( h / 6.0 ); return q; } //****************************************************************************80 void hermite_cubic_lagrange_value ( double x1, double x2, int n, double x[], double f[], double d[], double s[], double t[] ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_LAGRANGE_VALUE evaluates the Hermite cubic Lagrange polynomials. // // Discussion: // // The Hermite cubic polynomial P(X) for interval (X1,X2) and data // (F1,D1,F2,D2) satisfies: // // P(X1) = F1, // P'(X1) = D1, // P(X2) = F2, // P'(X2) = D2. // // We can determine four Lagrange polynomials L1(X) through L4(X) so that // // P(X) = F1 * L1(X) + D1 * L2(X) + F2 * L3(X) + D2 * L4(X). // // This function returns the values and derivatives of these four // polynomials. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 17 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, double X1, X2, the endpoints. // // Input, int N, the number of sample points. // // Input, double X[N], the sample points. // // Output, double F[4*N], D[4*N], S[4*N], T[4*N], the value // and first three derivatives of the Hermite cubic Lagrange polynomials // at X. // { double dx; double h; int j; h = x2 - x1; for ( j = 0; j < n; j++ ) { dx = x[j] - x1; // // F1. // f[0+j*4] = 1.0 + ( ( dx * dx ) / ( h * h ) ) * ( - 3.0 + ( dx / h ) * 2.0 ); d[0+j*4] = ( dx / ( h * h ) ) * ( - 6.0 + ( dx / h ) * 6.0 ); s[0+j*4] = ( 1.0 / ( h * h ) ) * ( - 6.0 + ( dx / h ) * 12.0 ); t[0+j*4] = ( 1.0 / ( h * h * h ) ) * 12.0; // // D1 // f[1+j*4] = dx + ( ( dx * dx ) / h ) * ( - 2.0 + ( dx / h ) ); d[1+j*4] = 1.0 + ( dx / h ) * ( - 4.0 + ( dx / h ) * 3.0 ); s[1+j*4] = ( 1.0 / h ) * ( - 4.0 + ( dx / h ) * 6.0 ); t[1+j*4] = ( 1.0 / ( h * h ) ) * 6.0; // // F2 // f[2+j*4] = ( ( dx * dx ) / ( h * h ) ) * ( 3.0 - 2.0 * ( dx / h ) ); d[2+j*4] = ( dx / ( h * h ) ) * ( 6.0 - 6.0 * ( dx / h ) ); s[2+j*4] = ( 1.0 / ( h * h ) ) * ( 6.0 - 12.0 * ( dx / h ) ); t[2+j*4] = ( 1.0 / ( h * h * h ) ) * ( - 12.0 ); // // D2 // f[3+j*4] = ( ( dx * dx ) / h ) * ( - 1.0 + ( dx / h ) ); d[3+j*4] = ( dx / h ) * ( - 2.0 + ( dx / h ) * 3.0 ); s[3+j*4] = ( 1.0 / h ) * ( - 2.0 + ( dx / h ) * 6.0 ); t[3+j*4] = ( 1.0 / h ) * 6.0; } return; } //****************************************************************************80 double hermite_cubic_spline_integral ( int nn, double xn[], double fn[], double dn[] ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_SPLINE_INTEGRAL: Hermite cubic spline integral. // // Discussion: // // The integral is taken over the definition interval ( X[0], X[NN-1] ). // // Note that if the intervals are equal in size, then the derivative // information in DN has no effect on the integral value, // except for the first and last entries. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 13 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, int NN, the number of data points. // // Input, double XN[NN], the coordinates of the data points. // The entries in XN must be in strictly ascending order. // // Input, double FN[NN], the function values. // // Input, double DN[NN], the derivative values. // // Output, double HERMITE_CUBIC_SPLINE_INTEGRAL, the integral of the // Hermite cubic spline over the interval X[0] <= X <= X[NN-1]. // { int i; double q; q = 0.0; for ( i = 0; i < nn - 1; i++ ) { q = q + 0.5 * ( xn[i+1] - xn[i] ) * ( fn[i] + fn[i+1] + ( xn[i+1] - xn[i] ) * ( dn[i] - dn[i+1] ) / 6.0 ); } return q; } //****************************************************************************80 double *hermite_cubic_spline_integrate ( int nn, double xn[], double fn[], double dn[], int n, double a[], double b[] ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_SPLINE_INTEGRATE integrate Hermite cubic spline over [A,B]. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 13 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, int NN, the number of data points. // // Input, double XN[NN], the coordinates of the data points. // The entries in XN must be in strictly ascending order. // // Input, double FN[NN], the function values. // // Input, double DN[NN], the derivative values. // // Input, int N, the number of integration intervals. // // Input, double A[N], B[N], the integration endpoints. // // Output, double HERMITE_CUBIC_SPLINE_INTEGRATE[N], the integral // over the interval [A,B]. // { double aa; double bb; int i; int ii; int j; int k; double *q; double s; q = new double[n]; i = n / 2; j = n / 2; for ( ii = 0; ii < n; ii++ ) { q[ii] = 0.0; if ( a[ii] <= b[ii] ) { aa = a[ii]; bb = b[ii]; s = + 1.0; } else { aa = b[ii]; bb = a[ii]; s = - 1.0; } r8vec_bracket3 ( nn, xn, aa, &i ); r8vec_bracket3 ( nn, xn, bb, &j ); // // Evaluate the polynomial with the appropriate data. // if ( i == j ) { q[ii] = hermite_cubic_integrate ( xn[i], fn[i], dn[i], xn[i+1], fn[i+1], dn[i+1], aa, bb ); } else { q[ii] = hermite_cubic_integrate ( xn[i], fn[i], dn[i], xn[i+1], fn[i+1], dn[i+1], aa, xn[i+1] ); for ( k = i + 1; k < j; k++ ) { q[ii] = q[ii] + hermite_cubic_integral ( xn[k], fn[k], dn[k], xn[k+1], fn[k+1], dn[k+1] ); } q[ii] = q[ii] + hermite_cubic_integrate ( xn[j], fn[j], dn[j], xn[j+1], fn[j+1], dn[j+1], xn[j], bb ); } q[ii] = s * q[ii]; } return q; } //****************************************************************************80 double *hermite_cubic_spline_quad_rule ( int nn, double xn[] ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_SPLINE_QUAD_RULE: Hermite cubic spline quadrature rule. // // Discussion: // // The integral is taken over the definition interval ( X[0], X[NN-1] ). // // Note that if the intervals are equal in size, then the derivative // information in DN has no effect on the integral value, // except for the first and last entries. // // The quadrature rule is // // Integral ( XN[0] <= X <= XN[NN-1] ) F(X) dX is approximately // // Sum ( 0 <= I <= NN-1 ) W[0,I] * F(X[I]) + W[1,I] * F'(X[I]) // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 28 March 2011 // // Author: // // John Burkardt. // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, int NN, the number of data points. // // Input, double XN[NN], the coordinates of the data points. // The entries in XN must be in strictly ascending order. // // Output, double W[2*NN], the quadrature weights for F(1:NN) // and DN(1:NN). // { int j; double *w; w = new double[2*nn]; w[0+0*2] = 0.5 * ( xn[1] - xn[0] ); for ( j = 1; j < nn - 1; j++ ) { w[0+j*2] = 0.5 * ( xn[j+1] - xn[j-1] ); } w[0+(nn-1)*2] = 0.5 * ( xn[nn-1] - xn[nn-2] ); w[1+0*2] = pow ( xn[1] - xn[0], 2 ) / 12.0; for ( j = 1; j < nn - 1; j++ ) { w[1+j*2] = ( xn[j+1] - xn[j-1] ) * ( xn[j+1] - 2.0 * xn[j] + xn[j-1] ) / 12.0; } w[1+(nn-1)*2] = - pow ( xn[nn-2] - xn[nn-1], 2 ) / 12.0; return w; } //****************************************************************************80 void hermite_cubic_spline_value ( int nn, double xn[], double fn[], double dn[], int n, double x[], double f[], double d[], double s[], double t[] ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_SPLINE_VALUE evaluates a Hermite cubic spline. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 13 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, int NN, the number of data points. // // Input, double XN[NN], the coordinates of the data points. // The entries in XN must be in strictly ascending order. // // Input, double FN[NN], the function values. // // Input, double DN[NN], the derivative values. // // Input, int N, the number of sample points. // // Input, double X[N], the coordinates of the sample points. // // Output, double F[N], the function value at the sample points. // // Output, double D[N], the derivative value at the sample points. // // Output, double S[N], the second derivative value at the // sample points. // // Output, double T[N], the third derivative value at the // sample points. // { int i; int left; left = n / 2; for ( i = 0; i < n; i++ ) { r8vec_bracket3 ( nn, xn, x[i], &left ); hermite_cubic_value ( xn[left], fn[left], dn[left], xn[left+1], fn[left+1], dn[left+1], 1, x+i, f+i, d+i, s+i, t+i ); } return; } //****************************************************************************80 void hermite_cubic_to_power_cubic ( double x1, double f1, double d1, double x2, double f2, double d2, double *c0, double *c1, double *c2, double *c3 ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_TO_POWER_CUBIC converts a Hermite cubic to power form. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 13 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, double X1, F1, D1, the left endpoint, function value // and derivative. // // Input, double X2, F2, D2, the right endpoint, function value // and derivative. // // Output, double *C0, *C1, *C2, *C3, the power form of the polynomial. // { double df; double h; h = x2 - x1; df = ( f2 - f1 ) / h; // // Polynomial in terms of X - X1: // *c0 = f1; *c1 = d1; *c2 = - ( 2.0 * d1 - 3.0 * df + d2 ) / h; *c3 = ( d1 - 2.0 * df + d2 ) / h / h; // // Shift polynomial to X. // *c2 = *c2 - x1 * *c3; *c1 = *c1 - x1 * *c2; *c0 = *c0 - x1 * *c1; *c2 = *c2 - x1 * *c3; *c1 = *c1 - x1 * *c2; *c2 = *c2 - x1 * *c3; return; } //****************************************************************************80 void hermite_cubic_value ( double x1, double f1, double d1, double x2, double f2, double d2, int n, double x[], double f[], double d[], double s[], double t[] ) //****************************************************************************80 // // Purpose: // // HERMITE_CUBIC_VALUE evaluates a Hermite cubic polynomial. // // Discussion: // // The input arguments can be vectors. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 13 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, double X1, F1, D1, the left endpoint, function value // and derivative. // // Input, double X2, F2, D2, the right endpoint, function value // and derivative. // // Input, int N, the number of evaluation points. // // Input, double X[N], the points at which the Hermite cubic // is to be evaluated. // // Output, double F[N], D[N], S[N], T[N], the value and first // three derivatives of the Hermite cubic at X. // { double c2; double c3; double df; double h; int i; h = x2 - x1; df = ( f2 - f1 ) / h; c2 = - ( 2.0 * d1 - 3.0 * df + d2 ) / h; c3 = ( d1 - 2.0 * df + d2 ) / h / h; for ( i = 0; i < n; i++ ) { f[i] = f1 + ( x[i] - x1 ) * ( d1 + ( x[i] - x1 ) * ( c2 + ( x[i] - x1 ) * c3 ) ); d[i] = d1 + ( x[i] - x1 ) * ( 2.0 * c2 + ( x[i] - x1 ) * 3.0 * c3 ); s[i] = 2.0 * c2 + ( x[i] - x1 ) * 6.0 * c3; t[i] = 6.0 * c3; } return; } //****************************************************************************80 void power_cubic_to_hermite_cubic ( double c0, double c1, double c2, double c3, double x1, double x2, double *f1, double *d1, double *f2, double *d2 ) //****************************************************************************80 // // Purpose: // // POWER_CUBIC_TO_HERMITE_CUBIC converts a power cubic to Hermite form. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 12 February 2011 // // Author: // // John Burkardt // // Reference: // // Fred Fritsch, Ralph Carlson, // Monotone Piecewise Cubic Interpolation, // SIAM Journal on Numerical Analysis, // Volume 17, Number 2, April 1980, pages 238-246. // // Parameters: // // Input, double C0, C1, C2, C3, the power form of the // polynomial. // // Input, double X1, X2, the left and right endpoints of // the Hermite form. // // Output, double *F1, *D1, the function and derivative values at X1. // // Output, double *F2, *D2, the function and derivative values at X2. // { *f1 = c0 + x1 * ( c1 + x1 * ( c2 + x1 * c3 ) ); *d1 = c1 + x1 * ( 2.0 * c2 + x1 * 3.0 * c3 ); *f2 = c0 + x2 * ( c1 + x2 * ( c2 + x2 * c3 ) ); *d2 = c1 + x2 * ( 2.0 * c2 + x2 * 3.0 * c3 ); return; } //****************************************************************************80 double r8_uniform_01 ( int *seed ) //****************************************************************************80 // // Purpose: // // R8_UNIFORM_01 returns a unit pseudorandom R8. // // Discussion: // // This routine implements the recursion // // seed = ( 16807 * seed ) mod ( 2^31 - 1 ) // u = seed / ( 2^31 - 1 ) // // The integer arithmetic never requires more than 32 bits, // including a sign bit. // // If the initial seed is 12345, then the first three computations are // // Input Output R8_UNIFORM_01 // SEED SEED // // 12345 207482415 0.096616 // 207482415 1790989824 0.833995 // 1790989824 2035175616 0.947702 // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 11 August 2004 // // Author: // // John Burkardt // // Reference: // // Paul Bratley, Bennett Fox, Linus Schrage, // A Guide to Simulation, // Second Edition, // Springer, 1987, // ISBN: 0387964673, // LC: QA76.9.C65.B73. // // Bennett Fox, // Algorithm 647: // Implementation and Relative Efficiency of Quasirandom // Sequence Generators, // ACM Transactions on Mathematical Software, // Volume 12, Number 4, December 1986, pages 362-376. // // Pierre L'Ecuyer, // Random Number Generation, // in Handbook of Simulation, // edited by Jerry Banks, // Wiley, 1998, // ISBN: 0471134031, // LC: T57.62.H37. // // Peter Lewis, Allen Goodman, James Miller, // A Pseudo-Random Number Generator for the System/360, // IBM Systems Journal, // Volume 8, Number 2, 1969, pages 136-143. // // Parameters: // // Input/output, int *SEED, the "seed" value. Normally, this // value should not be 0. On output, SEED has been updated. // // Output, double R8_UNIFORM_01, a new pseudorandom variate, // strictly between 0 and 1. // { int i4_huge = 2147483647; int k; double r; if ( *seed == 0 ) { std::cerr << "\n"; std::cerr << "R8_UNIFORM_01 - Fatal error!\n"; std::cerr << " Input value of SEED = 0.\n"; std::exit ( 1 ); } k = *seed / 127773; *seed = 16807 * ( *seed - k * 127773 ) - k * 2836; if ( *seed < 0 ) { *seed = *seed + i4_huge; } // // Although SEED can be represented exactly as a 32 bit integer, // it generally cannot be represented exactly as a 32 bit real number. // r = ( double ) ( *seed ) * 4.656612875E-10; return r; } //****************************************************************************80 void r8vec_bracket3 ( int n, double t[], double tval, int *left ) //****************************************************************************80 // // Purpose: // // R8VEC_BRACKET3 finds the interval containing or nearest a given value. // // Discussion: // // An R8VEC is a vector of R8's. // // The routine always returns the index LEFT of the sorted array // T with the property that either // * T is contained in the interval [ T[LEFT], T[LEFT+1] ], or // * T < T[LEFT] = T[0], or // * T > T[LEFT+1] = T[N-1]. // // The routine is useful for interpolation problems, where // the abscissa must be located within an interval of data // abscissas for interpolation, or the "nearest" interval // to the (extreme) abscissa must be found so that extrapolation // can be carried out. // // This version of the function has been revised so that the value of // LEFT that is returned uses the 0-based indexing natural to C++. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 30 April 2009 // // Author: // // John Burkardt // // Parameters: // // Input, int N, length of the input array. // // Input, double T[N], an array that has been sorted into ascending order. // // Input, double TVAL, a value to be bracketed by entries of T. // // Input/output, int *LEFT. // On input, if 0 <= LEFT <= N-2, LEFT is taken as a suggestion for the // interval [ T[LEFT-1] T[LEFT] ] in which TVAL lies. This interval // is searched first, followed by the appropriate interval to the left // or right. After that, a binary search is used. // On output, LEFT is set so that the interval [ T[LEFT], T[LEFT+1] ] // is the closest to TVAL; it either contains TVAL, or else TVAL // lies outside the interval [ T[0], T[N-1] ]. // { int high; int low; int mid; // // Check the input data. // if ( n < 2 ) { std::cerr << "\n"; std::cerr << "R8VEC_BRACKET3 - Fatal error!\n"; std::cerr << " N must be at least 2.\n"; std::exit ( 1 ); } // // If *LEFT is not between 0 and N-2, set it to the middle value. // if ( *left < 0 || n - 2 < *left ) { *left = ( n - 1 ) / 2; } // // CASE 1: TVAL < T[*LEFT]: // Search for TVAL in (T[I],T[I+1]), for I = 0 to *LEFT-1. // if ( tval < t[*left] ) { if ( *left == 0 ) { return; } else if ( *left == 1 ) { *left = 0; return; } else if ( t[*left-1] <= tval ) { *left = *left - 1; return; } else if ( tval <= t[1] ) { *left = 0; return; } // // ...Binary search for TVAL in (T[I],T[I+1]), for I = 1 to *LEFT-2. // low = 1; high = *left - 2; for ( ; ; ) { if ( low == high ) { *left = low; return; } mid = ( low + high + 1 ) / 2; if ( t[mid] <= tval ) { low = mid; } else { high = mid - 1; } } } // // CASE 2: T[*LEFT+1] < TVAL: // Search for TVAL in (T[I],T[I+1]) for intervals I = *LEFT+1 to N-2. // else if ( t[*left+1] < tval ) { if ( *left == n - 2 ) { return; } else if ( *left == n - 3 ) { *left = *left + 1; return; } else if ( tval <= t[*left+2] ) { *left = *left + 1; return; } else if ( t[n-2] <= tval ) { *left = n - 2; return; } // // ...Binary search for TVAL in (T[I],T[I+1]) for intervals I = *LEFT+2 to N-3. // low = *left + 2; high = n - 3; for ( ; ; ) { if ( low == high ) { *left = low; return; } mid = ( low + high + 1 ) / 2; if ( t[mid] <= tval ) { low = mid; } else { high = mid - 1; } } } // // CASE 3: T[*LEFT] <= TVAL <= T[*LEFT+1]: // T is just where the user said it might be. // else { } return; } //****************************************************************************80 double *r8vec_even_new ( int n, double alo, double ahi ) //****************************************************************************80 // // Purpose: // // R8VEC_EVEN_NEW returns an R8VEC evenly spaced between ALO and AHI. // // Discussion: // // An R8VEC is a vector of R8's. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 18 May 2009 // // Author: // // John Burkardt // // Parameters: // // Input, int N, the number of values. // // Input, double ALO, AHI, the low and high values. // // Output, double R8VEC_EVEN_NEW[N], N evenly spaced values. // Normally, A[0] = ALO and A[N-1] = AHI. // However, if N = 1, then A[0] = 0.5*(ALO+AHI). // { double *a; int i; a = new double[n]; if ( n == 1 ) { a[0] = 0.5 * ( alo + ahi ); } else { for ( i = 0; i < n; i++ ) { a[i] = ( ( double ) ( n - i - 1 ) * alo + ( double ) ( i ) * ahi ) / ( double ) ( n - 1 ); } } return a; } //****************************************************************************80 double *r8vec_uniform_01_new ( int n, int *seed ) //****************************************************************************80 // // Purpose: // // R8VEC_UNIFORM_01_NEW returns a new unit pseudorandom R8VEC. // // Discussion: // // This routine implements the recursion // // seed = ( 16807 * seed ) mod ( 2^31 - 1 ) // u = seed / ( 2^31 - 1 ) // // The integer arithmetic never requires more than 32 bits, // including a sign bit. // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 19 August 2004 // // Author: // // John Burkardt // // Reference: // // Paul Bratley, Bennett Fox, Linus Schrage, // A Guide to Simulation, // Second Edition, // Springer, 1987, // ISBN: 0387964673, // LC: QA76.9.C65.B73. // // Bennett Fox, // Algorithm 647: // Implementation and Relative Efficiency of Quasirandom // Sequence Generators, // ACM Transactions on Mathematical Software, // Volume 12, Number 4, December 1986, pages 362-376. // // Pierre L'Ecuyer, // Random Number Generation, // in Handbook of Simulation, // edited by Jerry Banks, // Wiley, 1998, // ISBN: 0471134031, // LC: T57.62.H37. // // Peter Lewis, Allen Goodman, James Miller, // A Pseudo-Random Number Generator for the System/360, // IBM Systems Journal, // Volume 8, Number 2, 1969, pages 136-143. // // Parameters: // // Input, int N, the number of entries in the vector. // // Input/output, int *SEED, a seed for the random number generator. // // Output, double R8VEC_UNIFORM_01_NEW[N], the vector of pseudorandom values. // { int i; int i4_huge = 2147483647; int k; double *r; if ( *seed == 0 ) { cerr << "\n"; cerr << "R8VEC_UNIFORM_01_NEW - Fatal error!\n"; cerr << " Input value of SEED = 0.\n"; exit ( 1 ); } r = new double[n]; for ( i = 0; i < n; i++ ) { k = *seed / 127773; *seed = 16807 * ( *seed - k * 127773 ) - k * 2836; if ( *seed < 0 ) { *seed = *seed + i4_huge; } r[i] = ( double ) ( *seed ) * 4.656612875E-10; } return r; } //****************************************************************************80 void timestamp ( ) //****************************************************************************80 // // Purpose: // // TIMESTAMP prints the current YMDHMS date as a time stamp. // // Example: // // 31 May 2001 09:45:54 AM // // Licensing: // // This code is distributed under the MIT license. // // Modified: // // 08 July 2009 // // Author: // // John Burkardt // // Parameters: // // None // { # define TIME_SIZE 40 static char time_buffer[TIME_SIZE]; const struct std::tm *tm_ptr; std::time_t now; now = std::time ( NULL ); tm_ptr = std::localtime ( &now ); std::strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm_ptr ); std::cout << time_buffer << "\n"; return; # undef TIME_SIZE }