1 /*****************************************************************************
2 Major portions of this software are copyrighted by the Medical College
3 of Wisconsin, 1994-2000, and are released under the Gnu General Public
4 License, Version 2. See the file README.Copyright for details.
5 ******************************************************************************/
6
7 /*
8 This file contains routines to initialize and implement the
9 differential exponential drug response signal model.
10
11 File: model_diffexp.c
12 Author: B. Douglas Ward
13 Date: 6 June 1997
14 */
15
16
17 /*---------------------------------------------------------------------------*/
18
19 #include <math.h>
20 #include "NLfit_model.h"
21
22 void signal_model
23 (
24 float * gs, /* parameters for signal model */
25 int ts_length, /* length of time series data */
26 float ** x_array, /* independent variable matrix */
27 float * ts_array /* estimated signal model time series */
28 );
29
30
31 /*---------------------------------------------------------------------------*/
32 /*
33 Routine to initialize the signal model by defining the number of parameters
34 in the signal model, the name of the signal model, and the default values
35 for the minimum and maximum parameter constraints.
36 */
37
38 DEFINE_MODEL_PROTOTYPE
39
initialize_model()40 MODEL_interface * initialize_model ()
41 {
42 MODEL_interface * mi = NULL;
43
44
45 /*----- allocate memory space for model interface -----*/
46 mi = (MODEL_interface *) RwcMalloc (sizeof(MODEL_interface));
47
48
49 /*----- define interface for the differential - exponential model -----*/
50
51 /*----- name of this model -----*/
52 strcpy (mi->label, "DiffExp");
53
54 /*----- this is a signal model -----*/
55 mi->model_type = MODEL_SIGNAL_TYPE;
56
57 /*----- number of parameters in the model -----*/
58 mi->params = 4;
59
60 /*----- parameter labels -----*/
61 strcpy (mi->plabel[0], "t0");
62 strcpy (mi->plabel[1], "k");
63 strcpy (mi->plabel[2], "alpha1");
64 strcpy (mi->plabel[3], "alpha2");
65
66 /*----- minimum and maximum parameter constraints -----*/
67 mi->min_constr[0] = 45.0; mi->max_constr[0] = 75.0;
68 mi->min_constr[1] = -500.0; mi->max_constr[1] = 500.0;
69 mi->min_constr[2] = 0.00; mi->max_constr[2] = 0.15;
70 mi->min_constr[3] = 0.15; mi->max_constr[3] = 0.50;
71
72 /*----- function which implements the model -----*/
73 mi->call_func = &signal_model;
74
75
76 /*----- return pointer to the model interface -----*/
77 return (mi);
78 }
79
80
81 /*---------------------------------------------------------------------------*/
82 /*
83 Routine to calculate the time series which results from using the
84 differential exponential drug response signal model with the specified
85 model parameters.
86
87 Definition of model parameters:
88
89 gs[0] = time delay of response (t0)
90 gs[1] = multiplicative constant (k)
91 gs[2] = elimination rate constant (alpha1)
92 gs[3] = absorption rate constant (alpha2)
93 */
94
signal_model(float * gs,int ts_length,float ** x_array,float * ts_array)95 void signal_model
96 (
97 float * gs, /* parameters for signal model */
98 int ts_length, /* length of time series data */
99 float ** x_array, /* independent variable matrix */
100 float * ts_array /* estimated signal model time series */
101 )
102
103 {
104 int it; /* time index */
105 float t; /* time */
106 float fval; /* time series value at time t */
107
108
109 for (it = 0; it < ts_length; it++)
110 {
111 t = x_array[it][1];
112 if (t < gs[0])
113 fval = 0.0;
114 else
115 fval = gs[1] * (exp(-gs[2]*(t-gs[0])) - exp(-gs[3]*(t-gs[0])));
116 ts_array[it] = fval;
117 }
118
119 }
120
121
122
123
124