Thread: detecting "inf" and "nan" in sac

Started: 2011-08-17 05:53:17
Last activity: 2011-08-18 18:02:23
Topics: SAC Help
Igor
2011-08-17 05:53:17
Hello,

Is there any way to detect a non-number value (like inf and nan) in an if loop?
I couldn't find any references to this in the manual.
All versions below are simply ignored by sac:

mtw %min %max
rms to user0
setbb sta &1,user0

*** doesn't work:
if %sta eq inf
message "***** not a number ******"
endif

*** doesn't work:
if %sta eq "inf"
message "***** not a number ******"
endif


Note, this works:
if %sta eq 0
message "***** detected zero ******"
endif

Thanks,
Igor

  • Igor
    2011-08-18 18:02:23
    Hello,

    This is a follow up question I asked below.

    I found a reference to isnan() call at
    http://www.iris.washington.edu/pipermail/sac-dev/2008-January/000058.html
    that says:
    BUG FIX: isNaN() unsuitable for double, changed to system
    command isnan(). Found while checking polezero constants.

    Is is possible to use isnan() and isinf() in a sac macro directly or indirectly?

    How else could I detect the nan and inf while in macro? It seems that
    the if loop below doesn't do a job (at least for me).

    I know I can implement this function in fortran through readsac1 but I
    am trying to write this in sac a macro only.
    Would you recommend not to do it for whatever reason?

    Thank you,
    Igor


    On Tue, Aug 16, 2011 at 10:53 PM, Igor Stubailo <stubailo<at>gmail.com> wrote:
    Hello,

    Is there any way to detect a non-number value (like inf and nan) in an if loop?
    I couldn't find any references to this in the manual.
    All versions below are simply ignored by sac:

    mtw %min %max
    rms to user0
    setbb sta &1,user0

    *** doesn't work:
    if %sta eq inf
    message "***** not a number  ******"
    endif

    *** doesn't work:
    if %sta eq "inf"
    message "***** not a number  ******"
    endif


    Note, this works:
    if %sta eq 0
    message "***** detected zero ******"
    endif

    Thanks,
    Igor



11:16:21 v.22510d55