/* Tools for testing univariate minimizers */
/* Last edited on 2023-02-19 13:41:22 by stolfi */

#ifndef minu_test_H
#define minu_test_H

#define _GNU_SOURCE
#include <stdint.h>

#include <epswr.h>

#include <minu_gen.h>

typedef void (*ProblemFunc) (void *prb, double x, double *fx, double *dfx);

typedef double (*ProblemError) (void *prb, double x, double fx);

typedef double (*Function) (double x);

typedef bool_t (*GoodProc) (double x, double fx);

typedef struct Problem 
  { char *name;                /* Problem's name. */
    ProblemFunc eval;          /* Function to optimize. */
    ProblemError error;        /* Error evaluator. */
    double xMin; double xMax;  /* Nominal range of "x". */
    double yMin; double yMax;  /* Range of "f(x)", for plotting. */
    double xStart;             /* Starting "x" value */
    double tol;                /* Required precision */
    double dist;               /* Estimated distance from "xStart" to minimum */
    unsigned maxCalls;         /* Maximum number of calls to "f" */
  } Problem;

typedef struct Minimizer 
  { char *name;                /* Name of method */
    MinimizeProc minimize;     /* Minimizer procedure */
    bool_t usesDerivative;       /* TRUE if method uses derivative info. */
  } Minimizer;

typedef struct Performance 
  { unsigned nTests;     /* Number of tests run */
      /* The standard deviations are significative only if "nTests >= 2". */
    double avgCalls;     /* Average number of function calls per test */
    double devCalls;     /* Standard deviation of function calls per test */
    unsigned maxCalls;   /* Max number of function calls per test. */
       /* Negative error is interpreted as zero error: */    
    double avgError;     /* Average solution error per test */
    double devError;     /* Standard deviation of solution error per test */
    double maxError;     /* Max solution error among all tests */ 
    unsigned nFailures;  /* Number of times that error was positive. */
  } Performance;

// PROCEDURES 

Performance minu_test_single
  ( int32_t i_opt,   /* Index of minimizer, for file name. */
    Minimizer *opt,  /* The minimization tool */
    int32_t i_prb,   /* Index of problem, for file name. */
    Problem *prb,    /* Function and parameters */
    bool_t debug     /* Passed to the minimizer */
  );
  /* Runs the {minimizer} on the {problem} and prints the results.
    Also appends to {eps} a new page with a plot of the function,
    showing the {minimizer}'s probes. */
  
Performance minu_test_multiple
  ( int32_t i_opt,     /* Index of minimizer, for file names. */
    Minimizer *opt,    /* The minimization tool */
    int32_t i_prb,     /* Index of problem, for file names. */
    Problem *prb,      /* Function and parameters */
    unsigned nTests    /* Number of tests to perform. */
  );
  /* Runs {nTests} tests with random starting points. 
    Prints averages etc. */

#endif