Re: [Boost-users] [format] print float number with fixed number of decimals *and* integer digits

On Thu, Sep 30, 2010 at 5:41 PM, Larry wrote:

I believe if you use something like "%015.8lf" you will get more of what you want. I always think that the .8 is the number of digits to the right of decimal and the 15 is the entire field width (including sign, any leading zero digits,  any digits to the left of the decimal, the decimal point, and digits to the right of decimal point).

Right, I though that the number before the dot . was the number of integer digits not the total number of digits. std::cout<< boost::format("%015.8f") % d << std::endl; works, prints 000003.14150000 Thank you, Alfredo

For example:

double pi(3.141592);

 format a("%015.8lf");  a % pi;  printf("%s\n",a.str().c_str());

prints:

000003.14159200

Larry ----- Original Message ----- From: "alfC" To: Sent: Thursday, September 30, 2010 7:21 PM Subject: [Boost-users] [format] print float number with fixed number of decimals *and* integer digits

...

I always found the rules for printf formatting, which Boost.Format uses, cryptic. I usually find the right combination by trial and error. In this case I want to print decimal numbers with both fixed number of integer digits and decimal digits. How can I do this with Boost.Format.

#include #include<iostream> int main(){  int i = 2;  std::cout << boost::format("%04i") % i << std::endl; //prints 0002, ok!  double d = 3.1415;  std::cout<< boost::format("%04.8f") % d  << std::endl;  // ^ prints 3.14150000,  //   want   0003.14150000  //(or even '   3.14150000')  //(or even '   3.1415    ')  return 0; }

Thank you, Alfredo

_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users