From 0d6bb5d44d8e815ebf6ccce1dae2f83178780e7b Mon Sep 17 00:00:00 2001
From: Joseph Redmon <pjreddie@gmail.com>
Date: Tue, 03 Dec 2013 00:41:40 +0000
Subject: [PATCH] Working?
---
src/utils.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 files changed, 42 insertions(+), 0 deletions(-)
diff --git a/src/utils.c b/src/utils.c
index 9848d08..8229b2d 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -143,5 +143,47 @@
return field;
}
+double mean_array(double *a, int n)
+{
+ int i;
+ double sum = 0;
+ for(i = 0; i < n; ++i) sum += a[i];
+ return sum/n;
+}
+double variance_array(double *a, int n)
+{
+ int i;
+ double sum = 0;
+ double mean = mean_array(a, n);
+ for(i = 0; i < n; ++i) sum += (a[i] - mean)*(a[i]-mean);
+ double variance = sum/n;
+ return variance;
+}
+double constrain(double a, double max)
+{
+ if(a > abs(max)) return abs(max);
+ if(a < -abs(max)) return -abs(max);
+ return a;
+}
+
+void normalize_array(double *a, int n)
+{
+ int i;
+ double mu = mean_array(a,n);
+ double sigma = sqrt(variance_array(a,n));
+ for(i = 0; i < n; ++i){
+ a[i] = (a[i] - mu)/sigma;
+ }
+ mu = mean_array(a,n);
+ sigma = sqrt(variance_array(a,n));
+}
+
+double rand_normal()
+{
+ int i;
+ double sum= 0;
+ for(i = 0; i < 12; ++i) sum += (double)rand()/RAND_MAX;
+ return sum-6.;
+}
--
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