making atanf2 with atanf

[Claymz]

hi,

im trying to make atanf2 function (float MyArcTangent(float y, float x);) with atanf function (..).

But im having problem with the autput values, i cant seem to find out whats wrong

#include <iostream>
#include <cmath>
using namespace std;

float theta;

void MyArcTangent(float y, float x);

int main()
{
	MyArcTangent( 4, 2 );
	MyArcTangent( 5, -1 );
	MyArcTangent( -4, -6 );
	MyArcTangent( -6, 4 );
}

void MyArcTangent(float y, float x)
{
	
	if( x > 0 )
	{
		theta = atanf(y/x);              
	}
	else
		theta = atanf(y/x) + 180.0f;   
	
	cout << "MyArcTangent( " << y << ", " << x << ") = " << theta << endl;

}

i should get these values:

MyArcTangent( 4, 2) = 63.4671
MyArcTangent( 5, -1) = 101.27
MyArcTangent(-4, -6) = 213.707
MyArcTangent(-6, 4) = -56.3385

but instead, i get 1.10715, 178.672,...

ty for all the help

[Bazzy]

Trigonometric function take/give radian values, try to fix it in this way:
theta = atanf(y/x)*180/3.14;

[Claymz]

nah that didnt worked wrong output numbers again :(

[firedraco]

Try outputting some known values and see what atanf(y/x)*180/pi gives...like 3/4 should give 60 if I remembering correctly.

[minaadel1994]

Lol it worked perfectly for me =S....

[Claymz]

minaadel1994 could you post full code of yours, so i can test it if it really works?

[Bazzy]

I think would be better if you post your full code to see what is wrong with it

[Claymz]

#include <iostream>
#include <cmath>
using namespace std;

float theta;

void MyArcTangent(float y, float x);

int main()
{
	MyArcTangent( 3, 4 );
	MyArcTangent( 5, -1 );
	MyArcTangent( -4, -6 );
	MyArcTangent( -6, 4 );
}

void MyArcTangent(float y, float x)
{
	
	if( x > 0 )
	{
		theta = atanf(y/x);              
	}
	else
		theta = atanf(y/x)*180/3.14;  
	
	cout << "MyArcTangent( " << y << ", " << x << ") = " << theta << endl;

}

edited the line you typed...

[Bazzy]

n*180/3.14 converts 'n' from randians to degrees.

void MyArcTangent(float y, float x)
{
	
	if( x > 0 )
	{
		theta = atanf(y/x)*180/3.14;              
	}
	else
		theta = atanf(y/x)*180/3.14 + 180;  
	
	cout << "MyArcTangent( " << y << ", " << x << ") = " << theta << endl;

}

[Claymz]

cool it works now, you should said that before :)

[firedraco]

*cough*Ithoughtitwasobvious*cough* It's not like the function is suddenly changed between uses...>.>