1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
/*******************************************************************************
** CalculateProbability.cpp
** Part of the mutual information toolbox
**
** Contains functions to calculate the probability of each state in the array
** and to calculate the probability of the joint state of two arrays
**
** Author: Adam Pocock
** Created 17/2/2010
**
** Copyright 2010 Adam Pocock, The University Of Manchester
** www.cs.manchester.ac.uk
**
** This file is part of MIToolbox.
**
** MIToolbox is free software: you can redistribute it and/or modify
** it under the terms of the GNU Lesser General Public License as published by
** the Free Software Foundation, either version 3 of the License, or
** (at your option) any later version.
**
** MIToolbox is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU Lesser General Public License for more details.
**
** You should have received a copy of the GNU Lesser General Public License
** along with MIToolbox. If not, see <http://www.gnu.org/licenses/>.
**
*******************************************************************************/
#include "MIToolbox.h"
#include "ArrayOperations.h"
#include "CalculateProbability.h"
JointProbabilityState calculateJointProbability(double *firstVector, double *secondVector, int vectorLength)
{
int *firstNormalisedVector;
int *secondNormalisedVector;
int *firstStateCounts;
int *secondStateCounts;
int *jointStateCounts;
double *firstStateProbs;
double *secondStateProbs;
double *jointStateProbs;
int firstNumStates;
int secondNumStates;
int jointNumStates;
int i;
double length = vectorLength;
JointProbabilityState state;
firstNormalisedVector = (int *) CALLOC_FUNC(vectorLength,sizeof(int));
secondNormalisedVector = (int *) CALLOC_FUNC(vectorLength,sizeof(int));
firstNumStates = normaliseArray(firstVector,firstNormalisedVector,vectorLength);
secondNumStates = normaliseArray(secondVector,secondNormalisedVector,vectorLength);
jointNumStates = firstNumStates * secondNumStates;
firstStateCounts = (int *) CALLOC_FUNC(firstNumStates,sizeof(int));
secondStateCounts = (int *) CALLOC_FUNC(secondNumStates,sizeof(int));
jointStateCounts = (int *) CALLOC_FUNC(jointNumStates,sizeof(int));
firstStateProbs = (double *) CALLOC_FUNC(firstNumStates,sizeof(double));
secondStateProbs = (double *) CALLOC_FUNC(secondNumStates,sizeof(double));
jointStateProbs = (double *) CALLOC_FUNC(jointNumStates,sizeof(double));
/* optimised version, less numerically stable
double fractionalState = 1.0 / vectorLength;
for (i = 0; i < vectorLength; i++)
{
firstStateProbs[firstNormalisedVector[i]] += fractionalState;
secondStateProbs[secondNormalisedVector[i]] += fractionalState;
jointStateProbs[secondNormalisedVector[i] * firstNumStates + firstNormalisedVector[i]] += fractionalState;
}
*/
/* Optimised for number of FP operations now O(states) instead of O(vectorLength) */
for (i = 0; i < vectorLength; i++)
{
firstStateCounts[firstNormalisedVector[i]] += 1;
secondStateCounts[secondNormalisedVector[i]] += 1;
jointStateCounts[secondNormalisedVector[i] * firstNumStates + firstNormalisedVector[i]] += 1;
}
for (i = 0; i < firstNumStates; i++)
{
firstStateProbs[i] = firstStateCounts[i] / length;
}
for (i = 0; i < secondNumStates; i++)
{
secondStateProbs[i] = secondStateCounts[i] / length;
}
for (i = 0; i < jointNumStates; i++)
{
jointStateProbs[i] = jointStateCounts[i] / length;
}
FREE_FUNC(firstNormalisedVector);
FREE_FUNC(secondNormalisedVector);
FREE_FUNC(firstStateCounts);
FREE_FUNC(secondStateCounts);
FREE_FUNC(jointStateCounts);
firstNormalisedVector = NULL;
secondNormalisedVector = NULL;
firstStateCounts = NULL;
secondStateCounts = NULL;
jointStateCounts = NULL;
/*
**typedef struct
**{
** double *jointProbabilityVector;
** int numJointStates;
** double *firstProbabilityVector;
** int numFirstStates;
** double *secondProbabilityVector;
** int numSecondStates;
**} JointProbabilityState;
*/
state.jointProbabilityVector = jointStateProbs;
state.numJointStates = jointNumStates;
state.firstProbabilityVector = firstStateProbs;
state.numFirstStates = firstNumStates;
state.secondProbabilityVector = secondStateProbs;
state.numSecondStates = secondNumStates;
return state;
}/*calculateJointProbability(double *,double *, int)*/
ProbabilityState calculateProbability(double *dataVector, int vectorLength)
{
int *normalisedVector;
int *stateCounts;
double *stateProbs;
int numStates;
/*double fractionalState;*/
ProbabilityState state;
int i;
double length = vectorLength;
normalisedVector = (int *) CALLOC_FUNC(vectorLength,sizeof(int));
numStates = normaliseArray(dataVector,normalisedVector,vectorLength);
stateCounts = (int *) CALLOC_FUNC(numStates,sizeof(int));
stateProbs = (double *) CALLOC_FUNC(numStates,sizeof(double));
/* optimised version, may have floating point problems
fractionalState = 1.0 / vectorLength;
for (i = 0; i < vectorLength; i++)
{
stateProbs[normalisedVector[i]] += fractionalState;
}
*/
/* Optimised for number of FP operations now O(states) instead of O(vectorLength) */
for (i = 0; i < vectorLength; i++)
{
stateCounts[normalisedVector[i]] += 1;
}
for (i = 0; i < numStates; i++)
{
stateProbs[i] = stateCounts[i] / length;
}
FREE_FUNC(stateCounts);
FREE_FUNC(normalisedVector);
stateCounts = NULL;
normalisedVector = NULL;
state.probabilityVector = stateProbs;
state.numStates = numStates;
return state;
}/*calculateProbability(double *,int)*/
|
