Formatting Output

Question

Hello fellow www-people!

I need to output numbers in scientific notation such that there is always a "0" before the decimal point.

e.g. For the number x = 134.87546, I need to produce the output 0.134875E03 NOT 1.348755E02

Does someone know how to do this?

Thanks in Advance --Shiraz.

Answer 1

int exponent = floor(log10(num)) + 1;

Then just print "0.", the number without decimals, "E", then the exponent.

Answer 2

int exp = (int)log10(input)+1;
double shifted = input / pow(10.0, exp);
printf("%fE%d", shifted, exp);

Answer 3

You may investigate using the Boost Format library which is a general output formatting library.