From faa7da232afaa109040fbf6ebd8aacf010aa267b Mon Sep 17 00:00:00 2001
From: Aleksandar Bukva <aleksandar.bukva@yandex.com>
Date: Thu, 11 Jun 2015 19:42:29 +0200
Subject: [PATCH 1/4] math: p_exp: Implement exp function using series

---
 src/math/p_exp.c | 45 ++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 42 insertions(+), 3 deletions(-)

diff --git a/src/math/p_exp.c b/src/math/p_exp.c
index aa5fc5b..20c973e 100644
--- a/src/math/p_exp.c
+++ b/src/math/p_exp.c
@@ -3,7 +3,7 @@
 /**
  *
  * Calculate exponent (e^a), where e is the base of the natural logarithm
- * (2.71828.)
+ * (2.71828.) Using series expansion of function
  *
  * @param a     Pointer to input vector
  *
@@ -18,12 +18,51 @@
  * @return      None
  *
  */
-#include <math.h>
+static const int precision = 0.1e-6;
+
+float inverse(float a) //function to calucalte inverse without division operator using Newton Raphson method
+{
+	float result = precision;
+	while(result * a > 1 + precision || result * a < 1 - precision)
+	{
+		result *= (2 - a * result);
+	}
+	return result;
+}
+
+float single_exp(float b)
+{
+	float a = b;
+	if(b < 0) //if exponent is negative then calculate e^b and return 1/e^b
+	{
+		a = -a;
+	}
+	float result = 1;
+	float counter = 1;
+	float next_term = 1;
+	float old_result;
+	float error;
+	do
+	{
+		old_result = result;
+		next_term = next_term * a * inverse(counter);
+		result += next_term;
+		counter += 1;
+		error = (old_result - result) / result;
+		if(error < 0)
+		{
+			error = -error;
+		}
+	}while(error > precision);
+	if(b < 0)
+		return inverse(result);
+	return result;
+}
 void p_exp_f32(const float *a, float *c, int n, int p, p_team_t team)
 {
 
     int i;
     for (i = 0; i < n; i++) {
-        *(c + i) = expf(*(a + i));
+        *(c + i) = single_exp(*(a + i));
     }
 }

From 1f4a121268b64a1dfcd83b4dcdd3166a19e8e0a1 Mon Sep 17 00:00:00 2001
From: Aleksandar Bukva <aleksandar.bukva@yandex.com>
Date: Fri, 12 Jun 2015 01:19:29 +0200
Subject: [PATCH 2/4] math: p_exp: Corrected previous version

---
 src/math/p_exp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/math/p_exp.c b/src/math/p_exp.c
index 20c973e..b107995 100644
--- a/src/math/p_exp.c
+++ b/src/math/p_exp.c
@@ -18,7 +18,7 @@
  * @return      None
  *
  */
-static const int precision = 0.1e-6;
+static const float precision = 0.1e-6;
 
 float inverse(float a) //function to calucalte inverse without division operator using Newton Raphson method
 {

From 91975c9c4553d9fd40650c8102bf4b21a66aff3e Mon Sep 17 00:00:00 2001
From: Aleksandar Bukva <aleksandar.bukva@yandex.com>
Date: Fri, 12 Jun 2015 11:56:35 +0200
Subject: [PATCH 3/4] Fixing build error

---
 src/math/p_exp.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/math/p_exp.c b/src/math/p_exp.c
index befbbe3..b107995 100644
--- a/src/math/p_exp.c
+++ b/src/math/p_exp.c
@@ -11,10 +11,13 @@
  *
  * @param n     Size of 'a' and 'c' vector.
  *
+ * @param p     Number of processor to use (task parallelism)
+ *
+ * @param team  Team to work with 
+ *
  * @return      None
  *
  */
-<<<<<<< HEAD
 static const float precision = 0.1e-6;
 
 float inverse(float a) //function to calucalte inverse without division operator using Newton Raphson method
@@ -56,10 +59,6 @@ float single_exp(float b)
 	return result;
 }
 void p_exp_f32(const float *a, float *c, int n, int p, p_team_t team)
-=======
-#include <math.h>
-void p_exp_f32(const float *a, float *c, int n)
->>>>>>> upstream/master
 {
 
     int i;

From a1fa70f2f0959d0ab392567dbf878644d00bf66a Mon Sep 17 00:00:00 2001
From: Aleksandar Bukva <aleksandar.bukva@yandex.com>
Date: Fri, 12 Jun 2015 12:06:44 +0200
Subject: [PATCH 4/4] changed fucntion declarationt to match with current
 version without team parameter

---
 src/math/p_exp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/math/p_exp.c b/src/math/p_exp.c
index b107995..6ca5c9c 100644
--- a/src/math/p_exp.c
+++ b/src/math/p_exp.c
@@ -58,7 +58,7 @@ float single_exp(float b)
 		return inverse(result);
 	return result;
 }
-void p_exp_f32(const float *a, float *c, int n, int p, p_team_t team)
+void p_exp_f32(const float *a, float *c, int n)
 {
 
     int i;