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POObj-C Calculator - Radians to Degrees
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copied!<p>I've been watching the Stanford CS193P lectures and I've been working on the assignment calculator. I got through the first assignment fairly easily, and I'm trying to do the extra credit for the assignment now. I'm stuck however at one of the extra credit questions:</p> <p><em>Implement a user-interface for choosing whether the operand to sin() or cos() is considered radians or degrees. When you call sin(x) in the C library, x is assumed to be in radians (i.e. 0 to 2π goes around the circle once), but users might want to enter 180 and press the sin button and get 0 instead of -0.8012 (which is the sine of 180 radians). You could use a UIButton for this and switch out the titleLabel’s text each time the UIButton is pressed, but a better way would be to see if you can figure out how to use a UISwitch by reading the documentation (if you dare!).</em></p> <p>I implemented a UISwitch and hooked it up as an IBOutlet. When I perform an 'operation', I check if the switch is on or off and pass this to my model along with the operation to perform. In my sin and cos cases, I do the following:</p> <pre><code>else if ([operation isEqual:@"sin"]) { if (radians) { operand = sin(operand); } else { operand = sin(operand) * (180 / M_PI); } } // similar for cos </code></pre> <p>If <code>radians</code> (which is a BOOL: YES = radians, no = degrees), then I perform the operation as usually; if the user puts the switch to 'degrees', I want to return the value in degrees, as the assignment states: <em>users might want to enter 180 and press the sin button and get 0 instead of -0.8012 (which is the sine of 180 radians).</em></p> <p>However, this code doesn't fully work. When I put the switch to degrees and do <code>sin 180</code> it returns a value of more or less <code>-45</code>. Something is wrong there; and I'm not really sure what. I have looked up how to do the conversion and I think I'm doing it right, but apparently not.</p> <p>I realise this is perhaps better suited for math.stackexchange, but since there was some code I wanted to post I put it here. Can someone provide some advice on the best way to implement this? It's been a while since I even worked with cos or sin, radians and degrees.</p> <p>Thanks!</p>

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