More Pow Problems

[zbREy60M]

This doesn't make any sense to me. The pow() that is causing the problem is pow(10,45). When I take that term out and replace it with (1) or any other number the program compiles without problem. I need some way to write 10^45, I've tried typing 10000000000000000000000000000000000000000000000 and it says the constant is too long, and this pow function is not working. what do?

double postfrequency = pow( a*(20*(300000000))/(32*(pow ( (3.1415), 4))*(6.673*.000000000001)*(pow(10,45))* (pow (E, 2))), .25);

1>error C2668: 'pow' : ambiguous call to overloaded function
1> c:\program files (x86)\microsoft visual studio 9.0\vc\include\math.h(575): could be 'long double pow(long double,int)'
1> c:\program files (x86)\microsoft visual studio 9.0\vc\include\math.h(527): or 'float pow(float,int)'
1> c:\program files (x86)\microsoft visual studio 9.0\vc\include\math.h(489): or 'double pow(double,int)'
1> while trying to match the argument list '(int, int)'

[anonymous23323124]

Write 45.0 and 10.0. Then the compiler will treat them as doubles, and it will know to call the double function.

As it is, you are passing integers - 45 and 10 - so the compiler tries to convert the integers into a type it can pass to the function. But if can convert integers to floats, doubles or long doubles, and it doesn't know which to choose, hence the errors.

[zbREy60M]

Thanks! Real handy to know.

[anonymous23323124]

Sure. If you want to have floats rather than doubles, you can then write 45.0f, 10.0f etc. Google "C++ literals" to find out more about this kind of thing.

[bartoli]

And if you write big constant integer numbers, to tell the compiler of what type they are, you can add the suffixes L (size of long i think), LL (size of long long), or U, UL and ULL for the unsigned equivalents. (The sizes i gave must depend on the architecture and compiler i guess)

Ex : 10000000000000000000000000000000000000000000000LL
Your number will still have to be storable in the integer size you specified of course

[ne555]

1e45

[Disch]

+1 @ ne555

I'm surprised you were the first to mention that =P