topic how to convert character string into integer in Intel® Fortran Compiler

how to convert character string into integer

maria — Mon, 24 May 2010 11:47:08 GMT

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.

how to convert character string into integer

mecej4 — Mon, 24 May 2010 12:02:32 GMT

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.

how to convert character string into integer

TimP — Mon, 24 May 2010 12:43:10 GMT

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

how to convert character string into integer

Steven_L_Intel1 — Mon, 24 May 2010 15:25:37 GMT

Quoting tim18

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

Not true.

how to convert character string into integer

TimP — Mon, 24 May 2010 21:02:24 GMT

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

how to convert character string into integer

jimdempseyatthecove — Mon, 24 May 2010 21:57:26 GMT

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

how to convert character string into integer

TimP — Mon, 24 May 2010 23:32:24 GMT

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.