00001 /*****************************************************************************
00002    Major portions of this software are copyrighted by the Medical College
00003    of Wisconsin, 1994-2000, and are released under the Gnu General Public
00004    License, Version 2.  See the file README.Copyright for details.
00005 ******************************************************************************/
00006    
00007 /*
00008   This file contains routines to initialize and implement the 
00009   gamma variate drug response signal model.
00010 
00011   File:     model_gammavar.c
00012   Author:   B. Douglas Ward
00013   Date:     29 May 1997
00014 
00015   Mod:      Tests for illegal parameter values.  Also, changed default
00016             constraint values.
00017   Date:     2 February 1998
00018 
00019 */
00020 
00021 
00022 /*---------------------------------------------------------------------------*/
00023 
00024 #include <math.h>
00025 #include "NLfit_model.h"
00026 
00027 void signal_model 
00028 (
00029   float * gs,                /* parameters for signal model */
00030   int ts_length,             /* length of time series data */
00031   float ** x_array,          /* independent variable matrix */
00032   float * ts_array           /* estimated signal model time series */  
00033 );
00034 
00035 
00036 /*---------------------------------------------------------------------------*/
00037 /*
00038   Routine to initialize the signal model by defining the number of parameters
00039   in the signal model, the name of the signal model, and the default values
00040   for the minimum and maximum parameter constraints.
00041 */
00042 
00043 DEFINE_MODEL_PROTOTYPE
00044 
00045 MODEL_interface * initialize_model ()
00046 {
00047   MODEL_interface * mi = NULL;
00048 
00049 
00050   /*----- allocate memory space for model interface -----*/
00051   mi = (MODEL_interface *) XtMalloc (sizeof(MODEL_interface));
00052 
00053 
00054   /*----- define interface for the gamma variate model -----*/   
00055 
00056   /*----- name of this model -----*/
00057   strcpy (mi->label, "GammaVar");
00058 
00059   /*----- this is a signal model -----*/
00060   mi->model_type = MODEL_SIGNAL_TYPE;
00061 
00062   /*----- number of parameters in the model -----*/
00063   mi->params = 4;
00064 
00065   /*----- parameter labels -----*/
00066   strcpy (mi->plabel[0], "t0");
00067   strcpy (mi->plabel[1], "k");
00068   strcpy (mi->plabel[2], "r");
00069   strcpy (mi->plabel[3], "b");
00070 
00071   /*----- minimum and maximum parameter constraints -----*/
00072   mi->min_constr[0] =    45.0;    mi->max_constr[0] =    75.0;
00073   mi->min_constr[1] =  -200.0;    mi->max_constr[1] =   200.0;
00074   mi->min_constr[2] =     0.0;    mi->max_constr[2] =     1.0;
00075   mi->min_constr[3] =     1.0;    mi->max_constr[3] =   100.0;
00076   
00077   /*----- function which implements the model -----*/
00078   mi->call_func = &signal_model;
00079 
00080 
00081   /*----- return pointer to the model interface -----*/
00082   return (mi);
00083 }
00084 
00085 
00086 /*---------------------------------------------------------------------------*/
00087 /*
00088   Routine to calculate the time series which results from using the
00089   gamma variate drug response signal model with the specified
00090   model parameters.
00091 
00092   Definition of model parameters:
00093 
00094          gs[0] = time delay of response (t0)  
00095          gs[1] = multiplicative constant (k)
00096          gs[2] = rise rate exponent (r)
00097          gs[3] = decay rate constant (b)
00098 
00099 */
00100 
00101 void signal_model 
00102 (
00103   float * gs,                /* parameters for signal model */
00104   int ts_length,             /* length of time series data */
00105   float ** x_array,          /* independent variable matrix */
00106   float * ts_array           /* estimated signal model time series */  
00107 )
00108 
00109 {
00110   int it;                           /* time index */     
00111   float t;                          /* time */
00112   float fval;                       /* time series value at time t */  
00113 
00114 
00115   for (it = 0;  it < ts_length;  it++)
00116     {
00117       t = x_array[it][1];
00118       if ((t <= gs[0]) || (gs[3] <= 0.0))
00119         fval = 0.0;
00120       else
00121         fval = gs[1] * exp( log(t-gs[0]) * gs[2] ) * exp(-(t-gs[0])/gs[3]);
00122       ts_array[it] = fval;
00123     }
00124   
00125 }
00126 
00127 
00128 
00129