Need help finding error

I am new to C++ and am working on an assignment for my class...

The error i am getting is the following:

Code:

c:\documents and settings\matt\my documents\visual studio 2005\projects\assignment 1a\assignment 1a\assignment 1b.cpp(8) : error C2668: 'atan' : ambiguous call to overloaded function
1>        c:\program files\microsoft visual studio 8\vc\include\math.h(545): could be 'long double atan(long double)'
1>        c:\program files\microsoft visual studio 8\vc\include\math.h(497): or 'float atan(float)'
1>        c:\program files\microsoft visual studio 8\vc\include\math.h(109): or 'double atan(double)'
1>        while trying to match the argument list '(int)'

The program:

Code:

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

int main (void)
{
	const double PI = 4*atan(1); //the constant Pi
	double d; //diameter
	double r; //radius
	double area; //area
	string name;  //your name
	
	cout << "What is your name?" << endl;
	cin >> name;

	cout << "Enter the diameter of a circle:" << endl;
	cin >> d;

	r = 1/2 *d;
	area = PI * r * r;

	cout << "Hi " << name << ", the area of a circle with a diameter of " 
		<< d << "is" << area << endl;

	return 0;
}

its probably something very intuitive for someone who has some experience but please help me out

thanks in advance!

hi i think u might need to put this

Code:

const double PI = 4*atan(1.0);

also if u put this u can see what happens

Code:

cout << "Hi " << name << ", the area of a circle with a diameter of " 
		<< d << "is" << area << endl;
                system("pause");
	return 0;
}

Code:

const double PI = 4*atan(1.0);

Just tried it...

I get this

fatal error LNK1169: one or more multiply defined symbols found

Code:

cout << "Hi " << name << ", the area of a circle with a diameter of " 
		<< d << "is" << area << endl;
                system("pause");
	return 0;

Doesnt help either

im running devcpp
and as the code is written it worked fine with me so i guess its time
for someone who knows what they doing to look at it sorry i cant be more help

when u wrote the code in did u add a new line or did u change what u had already?

what is devcpp? Is that the compiler u are using?

yep

I am using Visual C++ from microsoft if that has anything to do with it.

ok im not very good at this myself but it sounds like u defined something twice?
check your code to make sure any functions i.e main or variables are only defined once

would it make a difference if i have another source file in the same program with that also has a variable named "name:?

if u post all the source code ill see if i can fix it i do think that another name: in a source file will make an error if they are both in scope of each other

ok. here is the other source File

Code:

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

int main(void)

{
	string name;
	int age;

	cout << "What's your name? " << endl;
	cin >> name;

	cout << "How old are you?" << endl;
	cin >> age;

	cout << "Hello "<< name
		<< ", you will be " << age+1
		<< " years old on your next birthday." << endl;

	return (0);
}

and here is the second source file

Code:

#include <iostream>
#include <string>
#include <cmath>

using namespace std;

int main (void)
{
	const double PI = 4*atan(1.0);  //the constant Pi
	double d; //diameter
	double r; //radius
	double area; //area
	string n;  //your name
	
	cout << "What is your name?" << endl;
	cin >> n;

	cout << "Enter the diameter of a circle:" << endl;
	cin >> d;

	r = 1/2 *d;
	area = PI * r * r;

	cout << "Hi " << n << ", the area of a circle with a diameter of " 
		<< d << "is" << area << endl;
       
	return 0;
}

I am not sure what you mean by " in scope of each other".

Oh i figured it out!!

It didnt like that i had

Code:

int main (void);

in the two source files!

Thanks for your help anyways!

ok i think the problem is u have 2

Code:

int main ()

have u got these in a project file?

i mean if a variable is global then u can only have that name once
but if it is local to a function then u can have 2

{

lol well done an experienced c++ user would of spotted that straight away lol
sorry to of hinderd ya