how to convert character string into integer

[maria]

Hi,

I want to find the run time fora section of program in microseconds. Iput call date_and_time(data,time1)
and data_and_time(data,time2) at the beginning and the end of this section.
I know time1(8:10) and time2 (8:10) is the microseconds of the clock. Since this section is inside of a do loop, I want to calculate the total timewithin this session from the complete do loop.
How can I get time calculation with something like
t = t+ time2(8:10) - time1(8:10) if I set t = 0. outside of the do loop? In other words, how do I convert the character into integer here?

Thanks.

[mecej4]

You could do the following (read up on "internal files" in a Fortran book):

[fortran]    real :: t1,t2
    ...
    call date_and_time (data,time1)
    ...
    ...
    call date_and_time (data,time2)

    read(time1,123)t1
    read(time2,123)t2
123 format(F10.3)

    t_run = t2 - t1[/fortran]

Note, however, that it may be more appropriate for you to call CPU_TIME rather than using the wall-clock time as you have done, especially if you are using a multi-user/multi-process OS.

[TimP]

For wall-clock time, system_clock() may be more appropriate, although the resolution for Intel Windows compiler is limited to 60 Hz.

[Steven_L_Intel1]

Quoting tim18

the resolution for Intel Windows compiler is limited to 60 Hz.

Not true.

[TimP]

Then it would be useful to know how to change it, and why it doesn't just work as it does for linux.

[jimdempseyatthecove]

An easy way to do this is to build with OpenMP enabled (you do not need to use OpenMP within the application). add use omp_lib then

real(8) :: T1

...
T1 = OMP_GET_WTIME()

Returns a double-precision value equal to the elapsed wallclock time (in seconds) relative to an arbitrary reference time.

Jim Dempsey

[TimP]

In fact, Jim's suggestion is the way I do it for Windows, although I could get somewhat better results on most machines with QueryPerformance.