1 files changed, 48 insertions, 0 deletions
diff --git a/cosine.c b/cosine.c
new file mode 100644
index 0000000..58bd189
--- /dev/null
+++ b/cosine.c
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+/* 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;
+}