/* Miscellaneous functions and procedures */
/* Last edited on 2007-12-27 01:15:19 by stolfi */

#ifndef pz_proc_H
#define pz_proc_H

#include <pz_types.h>

int pz_round ( double x );
  /* Rounds {x} to the nearest integer; ties are broken
    by rounding-to-even. */
    
double fmax ( double x, double y );
double fmin ( double x, double y );
  /* Returns maximum and minimum, respectively, of the arguments. */

void pz_reduce_to_period
  ( double *t, /* IO */  
    double tLo,
    double tHi, 
    int *k  /* OUT */
  );
  /* Reduces {*t} to the range {[tLo _ tHi)} by adding to it
    some integer multiple {kk} of {tHi - tLo}. Returns {kk} in {*k}. */

double pz_squeeze
  ( double x, 
    double sigma 
  );
  /* Maps a variable {x} that has Gaussian distribution with mean zero
    and deviation {sigma} to a variable that is uniformly distributed
    n {[-1..+1]}. */

double pz_stretch
  ( double x, 
    double sigma 
  );
  /* The functional inverse of {pz_squeeze}. */

double pz_old_squeeze
  ( double x, 
    double epsilon,
    double delta 
  );
  /* Returns the {significant} value of {x} assuming it is contaminated
    by noise of absolute magnitude {epsilon} and relative magnitude {delta}.
    I.e. the result is approximately {x/epsilon} when {abs(x)} is small,
    and approximately {SGN(x)*log(abs(x))/delta} when {abs(x)} is large */

double pz_old_stretch
  ( double x, 
    double epsilon,
    double delta 
  );
  /* The functional inverse of {pz_old_squeeze}. */

double pz_interpolate
  ( double t, 
    double t0,
    double p0, 
    double t1,
    double p1 
  );
  /* Interpolates linearly the value at time {t} between 
    values {p0} and {p1}, assuming they have times {t0} and {t1}. */

double pz_cubic_interpolate
  ( double t, 
    double t0,
    double p0, 
    double t1,
    double p1,
    double t2,
    double p2,
    double t3,
    double p3 
  );
  /* Interpolates cubically some function at time
    {t}, assuming it has values {p0,..p3} at times {t0,..t3}. */

bool_vec_t pz_select_all( unsigned n );
  /* Returns a vector of {n} booleans, all TRUE. */

double pz_adjust_unit
  ( double givenUnit, 
    double dev,
    double big 
  );
  /* Adjusts the {givenUnit} for quantization of a variable 
    whose standard deviation is {dev} and whose values range
    in {[-big..+big]}.  Will increase {givenUnit} if needed to 
    avoid overflow, or decrease it to ensure quantization errors
    less than dev*10^-6.  In any case, if {givenUnit} is changed,
    or no good unit was found, also prints a warning to {stderr}. */

void pz_sort_ok
  ( int_vec_t *x, 
    bool_vec_t *ok 
  );
  /* Returns in {x} a permutation of the indices of {ok} that
    all elements {x[k]} with {ok[x[i]] == TRUE} are at the beginning. */

/*
  Copyright © 2001 Universidade Estadual de Campinas (UNICAMP).
  Authors: Helena C. G. Leitão and Jorge Stolfi.
  
  This file can be freely distributed, used, and modified, provided
  that this copyright and authorship notice is preserved, and that any
  modified versions are clearly marked as such.
  
  This software has NO WARRANTY of correctness or applicability for
  any purpose. Neither the authors nor their employers chall be held
  responsible for any losses or damages that may result from its use.
*/

#endif