tomwalters@0: /*
tomwalters@0:     Copyright (c) Applied Psychology Unit, Medical Research Council. 1988, 1989
tomwalters@0:     ===========================================================================
tomwalters@0: 
tomwalters@0:     Permission to use, copy, modify, and distribute this software without fee 
tomwalters@0:     is hereby granted for research purposes, provided that this copyright 
tomwalters@0:     notice appears in all copies and in all supporting documentation, and that 
tomwalters@0:     the software is not redistributed for any fee (except for a nominal shipping 
tomwalters@0:     charge). Anyone wanting to incorporate all or part of this software in a
tomwalters@0:     commercial product must obtain a license from the Medical Research Council.
tomwalters@0: 
tomwalters@0:     The MRC makes no representations about the suitability of this 
tomwalters@0:     software for any purpose.  It is provided "as is" without express or implied 
tomwalters@0:     warranty.
tomwalters@0:  
tomwalters@0:     THE MRC DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING 
tomwalters@0:     ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL THE
tomwalters@0:     A.P.U. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY 
tomwalters@0:     DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 
tomwalters@0:     AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 
tomwalters@0:     OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
tomwalters@0: */
tomwalters@0: 
tomwalters@0: /*
tomwalters@0: 	scales.c
tomwalters@0: 	========
tomwalters@0: 
tomwalters@0:     generates double arrays of numbers spaced on arbitrary frequency scales
tomwalters@0: 
tomwalters@0: */
tomwalters@0: 
tomwalters@0: #include <math.h>
tomwalters@0: 
tomwalters@0: #ifndef  _STITCH_H_
tomwalters@0: #include "stitch.h"
tomwalters@0: #endif
tomwalters@0: #ifndef  _SCALES_H_
tomwalters@0: #include "scales.h"
tomwalters@0: #endif
tomwalters@0: 
tomwalters@0: double *GenerateScale( min, max, density, base, inverse )
tomwalters@0: double min, max, density, base, (*inverse)() ;
tomwalters@0: {
tomwalters@0:     unsigned n_scale = NumberOnScale( min, max, density, base ) ;
tomwalters@0:     double *scale = NewArray( double, n_scale+1, "for scale in scales.c" ) ;
tomwalters@0:     double scale_start ;
tomwalters@0:     int i ;
tomwalters@0: 
tomwalters@0:     if( min != max ) {
tomwalters@0: 
tomwalters@0: 	scale_start = base - floor( ( base - min ) * density ) / density ;
tomwalters@0: 
tomwalters@0: 	/* fill array scale points 1./density apart */
tomwalters@0: 
tomwalters@0: 	for( i=0 ; i < n_scale  ; i++ )
tomwalters@0: 	    scale[ i ] = scale_start + i / density   ;
tomwalters@0: 
tomwalters@0: 	scale[ i++ ] = 0. ;
tomwalters@0:     }
tomwalters@0:     else {
tomwalters@0: 	scale[0] = min ;
tomwalters@0: 	scale[1] = 0.  ;
tomwalters@0:     }
tomwalters@0: 
tomwalters@0: 	/* convert scale space back to units required */
tomwalters@0: 
tomwalters@0:     if( inverse != (double ( * )()) 0 )
tomwalters@0: 	for( i=0 ; i < n_scale  ; i++ )
tomwalters@0: 	    scale[ i ] = inverse( scale[ i ] ) ;
tomwalters@0: 
tomwalters@0:     return ( scale ) ;
tomwalters@0: }
tomwalters@0: 
tomwalters@0: int NumberOnScale( min, max, density, base )
tomwalters@0: double min, max, density, base ;
tomwalters@0: {
tomwalters@0:     if( min != max )
tomwalters@0: 	return ( ( int ) ( ( floor( ( base - min ) * density ) + 1. + ( floor( ( max - base ) * density ) ) ) ) ) ;
tomwalters@0:     else
tomwalters@0: 	return ( 1 ) ;
tomwalters@0: }
tomwalters@0: 
tomwalters@0: double *NumberedScale( min, max, channels, inverse )
tomwalters@0: double min, max ;
tomwalters@0: int channels ;
tomwalters@0: double (*inverse)() ;
tomwalters@0: {
tomwalters@0:     DeclareNewArray( double, scale, channels+1, "for scale in scales.c" ) ;
tomwalters@0:     int chan ;
tomwalters@0: 
tomwalters@0:     scale[ 0 ] = min ;
tomwalters@0:     for( chan=1 ; chan < channels  ; chan++ )
tomwalters@0: 	scale[ chan ] = min + chan * (max-min) / ( channels - 1 ) ;
tomwalters@0: 
tomwalters@0:     if( inverse != (double ( * )()) 0 )
tomwalters@0: 	for( chan=0 ; chan < channels  ; chan++ )
tomwalters@0: 	    scale[ chan ] = inverse( scale[ chan ] ) ;
tomwalters@0: 
tomwalters@0:     scale[ channels ] = 0. ;
tomwalters@0: 
tomwalters@0:     return ( scale ) ;
tomwalters@0: }