GRASS GIS 8 Programmer's Manual
8.2.2dev(2023)-3d2c704037
var.c
Go to the documentation of this file.
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#include <math.h>
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#include <
grass/imagery.h
>
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/* sum: sum of x
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* sum2: sum of x squared
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* n: number of points
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*/
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double
I_variance
(
double
sum,
double
sum2,
int
n)
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{
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if
(n < 2)
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return
((
double
)0.0);
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else
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return
((sum2 - sum * sum / n) / (n - 1));
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}
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double
I_stddev
(
double
sum,
double
sum2,
int
n)
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{
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if
(n < 2)
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return
((
double
)-99.0);
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else
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return
sqrt(
I_variance
(sum, sum2, n));
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}
I_stddev
double I_stddev(double sum, double sum2, int n)
Definition:
var.c:16
imagery.h
I_variance
double I_variance(double sum, double sum2, int n)
Definition:
var.c:8
lib
imagery
var.c
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