Can someone please look at my helpers.c code for pset3? I worked a lot on this and I am stuck. 'wavelength' (which is frequency) doesn't calculate correctly within octave 4, and my code to add or subtract for other octaves isn't working.
// Helper functions for music
#include <cs50.h>
#include "helpers.h"
#include <math.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
// Converts a fraction formatted as X/Y to eighths
int duration(string fraction)
{
// TODO
//convert divisor to an integer
int numerator = fraction[0];
//convert divisor to an integer
int denominator = fraction[2];
//calculate how many eights
if (numerator == '1')
{ // 1 eighth note
if (denominator == '8')
{
return 1;
}
// quarter note
else if (denominator == '4')
{
return 2;
}
// half note
else if (denominator == '2')
{
return 4;
}
// whole note
else if (denominator == '1')
{
return 8;
}
}
else if (numerator == '3' && denominator == '8')
{ // 3/8ths
return 3;
}
else
{
return 0;
}
return 0;
}
// Calculates frequency (in Hz) of a note
int frequency(string note)
{
//define the letter character of string 'note'
char letter = note[0];
double wavelength; // returns frequency
//determine whether the number of the octave is the 2nd or 3rd character
int octaven;
//check if the 2nd character is a number
if ( (note[1] != '#') && (note[1] != 'b') )
{
octaven = note[1];
}
else
{
octaven = note[2];
}
// convert octaven from ascii value to number
octaven -= 48;
// Determine the distance of all notes to A4
int n = 0; //of the frequency formula
// double tone = 0.0; //frequency in an octave
switch (letter)
{
// if (letter == 'A')
case 'A':
{
n = 0;
}
break;
case 'B':
{
n = 2;
}
break;
case 'C':
if (letter == 'C')
{
n = -9;
}
break;
case 'D':
{
n = -7;
}
break;
case 'E':
{
n = -5;
}
break;
case 'F':
{
n = -4;
}
break;
case 'G':
{
n = -2;
}
break;
default:
printf("Support for this note will be added soon.");
break;
}
//check for sharps or flats
if (note[1] == '#')
{
n += 1;
}
else if (note[1] == 'b')
{
n-=1;
}
//test adjustment for accidentals
printf("%i\n", n);
//for any octaves other than 4
int tones; //store the difference between 4 and octave in question
if (octaven != 4)
{
// //get the difference between octave 4 and that octave
// you are making that adjustment, and returning before you use it to calculate the frequency.
tones = octaven - 4;
// //add or subtract the difference to n (subtract if it's a negative no)
n += tones * 12;
// return n;
double power = n / 12.00;
printf("%f\n", power);
// frequency = pow(2, n/12.0)*440 //Brenda
wavelength = pow(2, power) * 440;
return wavelength;
}
else
{
//test adjustment for tones
// printf("%f\n", tones);
// frequency = 2 ** (n / 12) * 440 // freq formula
// find the exponent value
double power = n / 12.00;
printf("%f\n", power);
// frequency = pow(2, n/12.0)*440 //Brenda
wavelength = pow(2, power) * 440;
return wavelength;
}
}
// Determines whether a string represents a rest
int beats;
bool is_rest(string s)
{
// check is user entered a blank line
if (strncmp(s, "", 1))
{
return false;
}
else
{
return true;
}
}
