\(\newcommand{\W}[1]{ \; #1 \; }\) \(\newcommand{\R}[1]{ {\rm #1} }\) \(\newcommand{\B}[1]{ {\bf #1} }\) \(\newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} }\) \(\newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} }\) \(\newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} }\) \(\newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }\)

exp_2_for1.cpp

View page source

exp_2: Verify First Order Forward Sweep

# include <cmath>                   // prototype for fabs
extern bool exp_2_for0(double *v0); // computes zero order forward sweep
bool exp_2_for1(double *v1)         // double v1[6]
{  bool ok = true;
   double v0[6];

   // set the value of v0[j] for j = 1 , ... , 5
   ok &= exp_2_for0(v0);

   v1[1] = 1.;                                     // v1 = x
   ok    &= std::fabs( v1[1] - 1. ) <= 1e-10;

   v1[2] = v1[1];                                  // v2 = 1 + v1
   ok    &= std::fabs( v1[2] - 1. ) <= 1e-10;

   v1[3] = v1[1] * v0[1] + v0[1] * v1[1];          // v3 = v1 * v1
   ok    &= std::fabs( v1[3] - 1. ) <= 1e-10;

   v1[4] = v1[3] / 2.;                             // v4 = v3 / 2
   ok    &= std::fabs( v1[4] - 0.5) <= 1e-10;

   v1[5] = v1[2] + v1[4];                          // v5 = v2 + v4
   ok    &= std::fabs( v1[5] - 1.5) <= 1e-10;

   return ok;
}
bool exp_2_for1(void)
{  double v1[6];
   return exp_2_for1(v1);
}