Trigonometry somewhat works

6 files changed, 82 insertions, 28 deletions

diff --git a/.gitignore b/.gitignore
index 782cf6d..7145c97 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 *.o
+*.out
 *.rej
 *.orig
 tags
diff --git a/cosine.c b/cosine.c
new file mode 100644
index 0000000..58bd189
--- /dev/null
+++ b/cosine.c
@@ -0,0 +1,48 @@
+/* cosine.c
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 42):
+ * <benjamin@chausse.xyz> wrote this file. As long as you retain this notice
+ * you can do whatever you want with this stuff. If we meet some day, and you
+ * think this stuff is worth it, you can buy me a beer in return.
+ * Benjamin Chausse
+ * ----------------------------------------------------------------------------
+ */
+#include <stdio.h>
+#include "format.h"
+#include "testData.h"
+
+float cos(float input, int precision){
+  float ttl = 1;
+  int denom = 1;
+  float num;
+  for (int i=2;i<=(2*precision);i+=2){
+    num = mpow(input,i);
+    denom *= i*(i-1);
+    // ttl += num/denom;
+    ttl += ( (i/2)%2 == 0 ) ? num/denom : -num/denom;
+  }
+  return ttl;
+}
+
+int main(){
+  const int precision = 16;
+  const float threshold = 1e-4;
+
+  for (int i=0; i<COUNT_OF(piValues);i++){
+    if ( abs(piValues[i][2]-cos(piValues[i][0],precision))>threshold ){
+      printf("ERROR: \n"
+             "Deviation between calculated value and expected value\n"
+             "surpasses threshold of %f for number %f\n"
+             "Expected: %f but got: %f\n",
+             threshold,
+             piValues[i][0],
+             piValues[i][2],
+             cos(piValues[i][0],precision));
+      return 1;
+    } else {
+      printf("%f IS ALL GOOD!\n",piValues[i][0]);
+    }
+  }
+
+  return 0;
+}
diff --git a/format.h b/format.h
index d0cf95a..3d51c3c 100644
--- a/format.h
+++ b/format.h
@@ -10,6 +10,7 @@
 
 #define TRUE 1
 #define FALSE 0
+
 #define COUNT_OF( arr) (sizeof(arr)/sizeof(0[arr]))
 
 // Conversion table between uppercase and lowercase
@@ -20,12 +21,14 @@ const char caps[2][26] = {
     'n','o','p','q','r','s','t','u','v','w','x','y','z'}
 };
 
-int pow(int b, int e){
-  int result =1;
-  for (int i = 0; i<e; i++){
-    result *= b;
+float mpow(float b, int e){
+  if (e==1){
+    return b;
+  } else if (e%2==0){
+    return mpow(b*b,e/2);
+  } else {
+    return b * mpow(b*b, e/2);
   }
-  return result;
 }
 
 float avg(float arr[]){
@@ -51,8 +54,8 @@ char * lower(char *str){
   return str;
 }
 
+// Count the total number of spaces to define the new str size
 char * trim(char *str){
-  // Count the total number of spaces to define the new str size
   int spc =0;
   for (int i=0; i<COUNT_OF(str); i++){
     if (str[i] == ' '){
@@ -71,3 +74,7 @@ char * trim(char *str){
   nstr[COUNT_OF(nstr)-1] = '\0';
   return nstr;
 }
+
+float abs(float i){
+  return (i>0) ? i : -i;
+}
diff --git a/sine.c b/sine.c
index 871acc0..204ab41 100644
--- a/sine.c
+++ b/sine.c
@@ -21,7 +21,7 @@ float sin(float input, int precision){
   for (int i=3;i<(2*precision)+2;i+=2) {
     num = mpow(input,i);
     denom *= i*(i-1);
-    ttl += ((i-1)/2 %2 == 1) ? -1*num/denom : num/denom;
+    ttl += ((i-1)/2 %2 == 1) ? -num/denom : num/denom;
   }
   return ttl;
 }
diff --git a/testData.h b/testData.h
index 9bf5e08..02b23c5 100644
--- a/testData.h
+++ b/testData.h
@@ -17,7 +17,7 @@
 //   - Trailing spaces         -> sis, heightened, minim
 //   - Spaces before the words -> sis, unholly, pop
 //   - Non latin alphabet (greek & russian)
-char *wrd[] = {
+const char *wrd[] = {
   "abba", "betrothed", "deified", "elevation", "genesis", "kayak", "murdum",
   " pop", "relinquish", "stats", "thirst", "abhorrent", "accentuated",
   "agoraphobia", " aibohphobia", "anemia", "bIb", "bittersweet", "bob",
@@ -40,7 +40,7 @@ char *wrd[] = {
  *   - Negative values
  *   - Values surpassing 2π
  */
-float piValues[20][3] = {
+const float piValues[20][3] = {
 // test-value  sin        cos
   { 0.000000,  0.000000,  1.000000}, // 0°
   { 0.523599,  0.500000,  0.866025}, // 30°
@@ -72,37 +72,37 @@ float piValues[20][3] = {
  *   - Identity matrix
  *
  */
-int mtrxA[3][3] = {
+const int mtrxA[3][3] = {
   {1, 2, 3},
   {4, 5, 6},
   {7, 8, 9}
 };
 
-int mtrxB[3][3] = {
+const int mtrxB[3][3] = {
   {3, 1, 4},
   {1, 5, 9},
   {2, 6, 5}
 };
 
-int mtrxNULL[3][3] = {
+const int mtrxNULL[3][3] = {
   {0, 0, 0},
   {0, 0, 0},
   {0, 0, 0}
 };
 
-int mtrxID[3][3] = {
+const int mtrxID[3][3] = {
   {1, 0, 0},
   {0, 1, 0},
   {0, 0, 1}
 };
 
-int mtrxWide[3][5] = {
+const int mtrxWide[3][5] = {
   {1,  2,  3,  4,  5},
   {6,  7,  8,  9,  10},
   {11, 12, 13, 14, 15}
 };
 
-int mtrxTall[5][3] = {
+const int mtrxTall[5][3] = {
   {1,  2,  3},
   {4,  5,  6},
   {7,  8,  9},
diff --git a/tools/gen-trig-test.c b/tools/gen-trig-test.c
index 365a90d..54b39bf 100644
--- a/tools/gen-trig-test.c
+++ b/tools/gen-trig-test.c
@@ -11,25 +11,24 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-/* This code was used to generate floating numbers found in testData.h
- * It's purpose is to generate a list of expected outputs for the sine
- * and cosine function with a given number. It uses the math.h library
+/* This code was used to generate double precision floating point numbers found
+ * in testData.h It's purpose is to generate a list of expected outputs for the
+ * sine and cosine function with a given number. It uses the math.h library
  * which cannot be used for the assignment and which is therefore a great
  * subject to test and compare with.
  *
- * The generated [][3]int list is organized as follows:
- * { original_value, expected_sine, expected_cosine }
+ * The generated [][3]int list is organized as follows: { original_value,
+ * expected_sine, expected_cosine }
  *
- * Values chosen here test the following edge cases,
- *   - Common trigonometric circle identities (0°,30°,45°,60°,90°, etc...)
- *   - Negative values
- *   - Values surpassing 2π
+ * Values chosen here test the following edge cases, - Common trigonometric
+ * circle identities (0°,30°,45°,60°,90°, etc...) - Negative values - Values
+ * surpassing 2π
  */
 
 int main(){
 
   // list of number {{{
-  float lst[20] = {
+  double lst[20] = {
     0,         // 0°
     M_PI/6,    // 30°
     M_PI/4,    // 45°
@@ -56,17 +55,16 @@ int main(){
 
   printf("int piValues[][] = {\n");
   int max = (sizeof(lst)/sizeof(lst[0]))-1;
-  printf("%d",max);
   for (int i=0; i<max; i++) {
     printf("  {%f, %f, %f},\n",
         lst[i],
         sin(lst[i]),
         cos(lst[i]));
   };
-  printf("  {%f, %f, %f}\n}",
+  printf("  {%f, %f, %f}\n}\n",
       lst[max],
       sin(lst[max]),
       cos(lst[max]));
 
-  return 0
+  return 0;
 }