# ifndef H_NEURAL_NET_ODE_H
# define H_NEURAL_NET_ODE_H

struct Neural_Net_ODE 
{
  double (*ODE)( double x, double u, double u_x, double u_xx );
  double a; // left endpoint of the interval
  double b; // right endpoint of the interval
  int q; // number of units in the hidden layer
  int nu; // the number of training points
  double *training_points; // the array of training points
  double (*exact_sol)(double x); // NULL if no exact solution available
//
// no user modifiable parts beyond this point!
//
  int nweights; // 3*q
  double *weights; // the array of u, v, w
  double sigma[3]; // array to hold sigma, sigma', sigma''
  double phi[3]; // array to hold phi, phi', phi''
  double N[3]; // array to hold N, N', N''
};

void Neural_Net_init ( struct Neural_Net_ODE *nn );
void Neural_Net_end ( struct Neural_Net_ODE *nn );
void Neural_Net_eval ( struct Neural_Net_ODE *nn, double x );
void Neural_Net_phi ( struct Neural_Net_ODE *nn, double x );
void Neural_Net_plot_with_maple ( struct Neural_Net_ODE *nn, int n, char *outfile );
void Neural_Net_plot_with_matlab ( struct Neural_Net_ODE *nn, int n, char *header );
double Neural_Net_residual ( double *weights, int nweights, void *params );
double Neural_Net_error_vs_exact ( struct Neural_Net_ODE *nn, int n );
double residual_at_x ( struct Neural_Net_ODE *nn, double x );
void sigmoid ( double x, double *sigma );

#endif