Few question

[ziad.sharif]

I'm relatively new to programming in C, and i have some questions if I may.

as i understood, log(q) for example will return a value of double nature with q being double as well, but i noticed i can use q as a floating variable, what difference is there is from using logf(q) or log(q) where q is a floating variable, what will happen if i'm using complex variables ? is this difference is the same between clog(q) and clogf(q) where q is complex floating variable ?

finaly am i allowed to define a fucntion for example:

complex float example(q)
{
float q;
}

where q is a real floating variable ?

[matsp]

You can only specify one type for a function return - complex is not an "extension" to the existing float type, so that is not correct. Your overall function is also wrong, as you need to declare what q is OUTSIDE of the braces.

--
Mats

[ziad.sharif]

you mean something like this is wrong?
as the q should be a complex floating variable?

complex float example( float q)
{
complex float Q;
...few lines of code
return Q;
}

what about the first few questions?

[ziad.sharif]

in the end how can i fix this code:
mb,mu,ms are defined outside the function.

complex float hqmb(float q) /*this function will calculate h(mb,q) where mb is the mass of the b quark, and q is the lepton pair invariant mass */
{
	m~b=mb/mu;
	complex float hq;
	real(hq)=-(4/9)*(log((m~b)^2)-(2/3)-4*((mb/q)^2))-(4/9)*(2+4*((mb/q)^2))*sqrt(fabs(1-4*((mb/q)^2)));
	if (4*ms^2>q^2)
	{
		real(hq)=real(hq)*atan(1/sqrt(4*((mb/q)^2))-1);
		imag(hq)=0;
	}
	else 
	{
		real(hq)=real(hq)*(log((1+sqrt(1-4*((mb/q)^2)))/(sqrt(4*((mb/q)^2)))));
		imag(hq)=(PI/2)*(4/9)*(log((m~b)^2)-(2/3)-4*((mb/q)^2))-(4/9)*(2+4*((mb/q)^2))*sqrt(fabs(1-4*((mb/q)^2)));
	}
	return hq;
}

[C_ntua]

A type is ONE thing, one word. You cannot have a type complex float. You could have a type complex_float, or complexFloat or just complex.
There is already a definition for complex numbers in a library, but you could also make your own type. For example

typedef struct complex_float
{
float real;
float imaginary;
} complex_float;

Dunno if this code makes sense for you

Then you would use lines like this:

complex_float* hqmb(float q)
{
...
complex_float* hq;
//allocate space for hq
hq->real -= ...    
hq->imaginary -= ...
...
return hq;
}

[quzah]

For starters, the carat isn't a "power of" marker, so you're going to have to use something in its place. Basically, if you're passing that whole thing off as a string, you're going to need a parser. If you're not passing that whole thing off as a string, then you actually need to use C and not just "math speak".


Quzah.