From 738cd4c2d7abcf62b85b759a5765b08380ee90e8 Mon Sep 17 00:00:00 2001
From: Joseph Redmon <pjreddie@gmail.com>
Date: Thu, 17 Apr 2014 00:05:29 +0000
Subject: [PATCH] Visualizations?
---
src/utils.c | 92 +++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 90 insertions(+), 2 deletions(-)
diff --git a/src/utils.c b/src/utils.c
index 9848d08..67a9ba1 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -123,9 +123,9 @@
return count;
}
-double *parse_fields(char *line, int n)
+float *parse_fields(char *line, int n)
{
- double *field = calloc(n, sizeof(double));
+ float *field = calloc(n, sizeof(float));
char *c, *p, *end;
int count = 0;
int done = 0;
@@ -143,5 +143,93 @@
return field;
}
+float mean_array(float *a, int n)
+{
+ int i;
+ float sum = 0;
+ for(i = 0; i < n; ++i) sum += a[i];
+ return sum/n;
+}
+float variance_array(float *a, int n)
+{
+ int i;
+ float sum = 0;
+ float mean = mean_array(a, n);
+ for(i = 0; i < n; ++i) sum += (a[i] - mean)*(a[i]-mean);
+ float variance = sum/n;
+ return variance;
+}
+
+float constrain(float a, float max)
+{
+ if(a > abs(max)) return abs(max);
+ if(a < -abs(max)) return -abs(max);
+ return a;
+}
+
+void normalize_array(float *a, int n)
+{
+ int i;
+ float mu = mean_array(a,n);
+ float 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));
+}
+
+void translate_array(float *a, int n, float s)
+{
+ int i;
+ for(i = 0; i < n; ++i){
+ a[i] += s;
+ }
+}
+
+void scale_array(float *a, int n, float s)
+{
+ int i;
+ for(i = 0; i < n; ++i){
+ a[i] *= s;
+ }
+}
+int max_index(float *a, int n)
+{
+ if(n <= 0) return -1;
+ int i, max_i = 0;
+ float max = a[0];
+ for(i = 1; i < n; ++i){
+ if(a[i] > max){
+ max = a[i];
+ max_i = i;
+ }
+ }
+ return max_i;
+}
+
+float rand_normal()
+{
+ int i;
+ float sum= 0;
+ for(i = 0; i < 12; ++i) sum += (float)rand()/RAND_MAX;
+ return sum-6.;
+}
+float rand_uniform()
+{
+ return (float)rand()/RAND_MAX;
+}
+
+float **one_hot_encode(float *a, int n, int k)
+{
+ int i;
+ float **t = calloc(n, sizeof(float*));
+ for(i = 0; i < n; ++i){
+ t[i] = calloc(k, sizeof(float));
+ int index = (int)a[i];
+ t[i][index] = 1;
+ }
+ return t;
+}
--
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