-
Notifications
You must be signed in to change notification settings - Fork 13
/
udf_steyx.cc
186 lines (159 loc) · 4.89 KB
/
udf_steyx.cc
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
185
#ifdef STANDARD
#include <stdio.h>
#include <string.h>
#ifdef __WIN__
typedef unsigned __int64 ulonglong;
typedef __int64 longlong;
#else
typedef unsigned long long ulonglong;
typedef long long longlong;
#endif /*__WIN__*/
#else
#include <my_global.h>
#include <my_sys.h>
#endif
#include <mysql.h>
#include <m_ctype.h>
#include <m_string.h>
extern "C" {
my_bool steyx_init( UDF_INIT* initid, UDF_ARGS* args, char* message );
void steyx_deinit( UDF_INIT* initid );
void steyx_clear(UDF_INIT *initid, char *is_null, char *is_error);
void steyx_reset( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error );
void steyx_add( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error );
double steyx( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error );
}
#define BUFFERSIZE 1024
struct steyx_data
{
int fCount;
double fSumX;
double fSumY;
double fSumDeltaXDeltaY; // sum of (ValX-MeanX)*(ValY-MeanY)
double fSumSqrDeltaX; // sum of (ValX-MeanX)^2
double fSumSqrDeltaY; // sum of (ValY-MeanY)^2
// Copying the values
double *valuesx;
double *valuesy;
int pages; // Number of buffers allocated
};
my_bool steyx_init( UDF_INIT* initid, UDF_ARGS* args, char* message )
{
if (args->arg_count != 2)
{
strcpy(message,"wrong number of arguments: steyx() requires two arguments");
return 1;
}
if ((args->arg_type[0]!=REAL_RESULT && args->arg_type[0]!=DECIMAL_RESULT) ||
(args->arg_type[1]!=REAL_RESULT && args->arg_type[1]!=DECIMAL_RESULT))
{
sprintf(message,"steyx() requires both real or decimal arguments: %d,%d",
(int)args->arg_type[0], (int)args->arg_type[1]);
return 1;
}
steyx_data *buf = new steyx_data;
buf->fCount = 0.0;
buf->fSumX = 0.0;
buf->fSumY = 0.0;
buf->fSumDeltaXDeltaY = 0.0; // sum of (ValX-MeanX)*(ValY-MeanY)
buf->fSumSqrDeltaX = 0.0; // sum of (ValX-MeanX)^2
buf->fSumSqrDeltaY = 0.0; // sum of (ValY-MeanY)^2
buf->valuesx = buf->valuesy = NULL;
buf->pages = 1;
initid->ptr = (char *)buf;
return 0;
}
void steyx_deinit( UDF_INIT* initid )
{
steyx_data *buf = (steyx_data *)initid->ptr;
if (buf->valuesx != NULL)
{
free(buf->valuesx);
buf->valuesx=NULL;
}
if (buf->valuesy != NULL)
{
free(buf->valuesy);
buf->valuesy=NULL;
}
delete buf;
}
void steyx_clear(UDF_INIT *initid, char *is_null, char *is_error)
{
steyx_data *buf = (steyx_data *)initid->ptr;
buf->fCount = 0.0;
buf->fSumX = 0.0;
buf->fSumY = 0.0;
buf->fSumDeltaXDeltaY = 0.0; // sum of (ValX-MeanX)*(ValY-MeanY)
buf->fSumSqrDeltaX = 0.0; // sum of (ValX-MeanX)^2
buf->fSumSqrDeltaY = 0.0; // sum of (ValY-MeanY)^2
if (buf->valuesx != NULL)
{
free(buf->valuesx);
}
if (buf->valuesy != NULL)
{
free(buf->valuesy);
}
buf->valuesx=(double *) malloc(BUFFERSIZE*sizeof(double));
buf->valuesy=(double *) malloc(BUFFERSIZE*sizeof(double));
buf->pages = 1;
*is_null = *is_error = 0;
}
void steyx_reset( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *is_error )
{
steyx_clear(initid, is_null, is_error);
steyx_add( initid, args, is_null, is_error );
}
static double parse_arg(UDF_ARGS *args, int index)
{
if (args->arg_type[index] == REAL_RESULT) {
return *((double*)args->args[index]);
} else {
double ret;
char *str;
str = (char *) malloc(args->lengths[index] + 1);
strncpy(str, args->args[index], args->lengths[index]);
str[args->lengths[index]] = '\0';
sscanf(str, "%lf", &ret);
free(str);
return ret;
}
}
void steyx_add( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error )
{
if (args->args[0]!=NULL && args->args[1]!=NULL) {
steyx_data *buf = (steyx_data *)initid->ptr;
double fValX = parse_arg(args, 0), fValY = parse_arg(args, 1);
if (buf->fCount >= BUFFERSIZE) {
buf->pages ++;
buf->valuesx = (double *)realloc(buf->valuesx, BUFFERSIZE*buf->pages*sizeof(double));
buf->valuesy = (double *)realloc(buf->valuesy, BUFFERSIZE*buf->pages*sizeof(double));
}
buf->valuesx[buf->fCount] = fValX;
buf->valuesy[buf->fCount] = fValY;
buf->fSumX += fValX;
buf->fSumY += fValY;
buf->fCount ++;
}
}
double steyx( UDF_INIT* initid, UDF_ARGS* args, char* is_null, char *error )
{
steyx_data *buf = (steyx_data *)initid->ptr;
const double fMeanX = buf->fSumX / buf->fCount;
const double fMeanY = buf->fSumY / buf->fCount;
double fValX, fValY;
for(int i = 0; i < buf->fCount; i++) {
fValX = buf->valuesx[i];
fValY = buf->valuesy[i];
buf->fSumDeltaXDeltaY += (fValX - fMeanX) * (fValY - fMeanY);
buf->fSumSqrDeltaX += (fValX - fMeanX) * (fValX - fMeanX);
buf->fSumSqrDeltaY += (fValY - fMeanY) * (fValY - fMeanY);
}
if (buf->fSumSqrDeltaX==0.0) {
*is_null = 1;
return 0.0;
}
return sqrt((buf->fSumSqrDeltaY - buf->fSumDeltaXDeltaY*buf->fSumDeltaXDeltaY/buf->fSumSqrDeltaX)
/ (buf->fCount-2));
}