adding floating point numbers

[codingGuy]

Hello all,

I'm trying to add two numbers, one is seconds and the other is nanoseconds (both in float), but when I do, my results don't come out correctly.
Can anyone help?

(I tried to expand the code out so that it can be easily examined)

float endingnano = (float)final.tv_nsec/1000000000;

float endingsec = final.tv_sec;

printf("Ending Nanoseconds = %f\n", endingnano);

printf("Ending Seconds = %f\n", endingsec);

float endingTime = endingnano + endingsec;
printf("Ending Time = %f\n", endingTime);

Results:
Ending Nanoseconds = 0.324691
Ending Seconds = 1318214528.000000
Ending Time = 1318214528.000000

[CommonTater]

To get the right answer you have to covert them to the same base... either convert endingnano to seconds or convert your endingsec to nanoseconds before adding... basic math.

[codingGuy]

I thought by dividing nanoseconds by 1000000000 i was converting it to seconds.

Why can't I add 1234.000000 and 0.123456 and get 1234.123456?

[TheBigH]

It may be that the float type hasn't got enough significant figures. Try changing all your floats to doubles and see if that helps.

[codingGuy]

That idea definitely works!

Thank you!