Just print them with the required number of digits after the decimal point:
double d = 2.483650149760682;
printf("%.12f\n", d);
See
printf - C++ Reference[
^] for the format options. To print to a buffer (prepare string) use
sprintf - C++ Reference[
^] or a formatting method of the used string class (if available, e.g.
CStringT::Format[
^] ).
When using C++ streams use the
setprecision - C++ Reference[
^] method.