Thread: 32bit limitation

Started: 2021-09-18 15:35:24
Last activity: 2021-09-19 15:04:28
Topics: SAC Help
Onur Tan
2021-09-18 15:35:24
Hi,

I use sac v102.0 (64bit) on Kubuntu v16 (64bit) .
After FFT of a squared waveform (amplitude unit is count), the maximum and
minimum values on the header are

FILE: 1-SAC/a.sac - 1
--------------------
DEPMAX = 1.441192e+13
DEPMIN = 7.639150e+07
NVHDR = 7

However, I give the following command
message " max-min &1,DEPMAX &1,DEPMIN "
max-min -2147483648 76391496

The maximum number is not true, so I cannot normalize the data.
The value of the &1,DEPMAX is the limit of 32bit-number (2^32)/2

Do you have any suggestions?

Best regards
Onur Tan

PS. Here is the sac binary
bin> file sac
sac: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically
linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32,
BuildID[sha1]=e8e1bcc88c9c35a7d485a1c78c1f93da6793deee, not s
tripped

  • Geo .
    2021-09-19 15:04:28
    Hi,
    If you want DEPMAX and DEPMIN for normalization only, why don't you write
    it to a blackboard variable and just divide?
    Something like this;

    SETBB normamp (MAX (ABSOLUTE &1,DEPMAX) (ABSOLUTE &1,DEPMIN))
    DIV %normamp

    Januka

    Januka Attanayake
    Research Fellow/Lecturer | Earthquake Seismology Lead
    Homepage: *https://sites.google.com/site/janukaattanayake
    https://sites.google.com/site/janukaattanayake*

    School of Geography, Earth & Atmospheric Sciences
    University of Melbourne | Parkville 3010 VIC
    Australia




    On Sat, 18 Sept 2021 at 22:41, Onur Tan (via IRIS) <
    sac-help-bounce<at>lists.ds.iris.edu> wrote:

    Hi,

    I use sac v102.0 (64bit) on Kubuntu v16 (64bit) .
    After FFT of a squared waveform (amplitude unit is count), the maximum and
    minimum values on the header are

    FILE: 1-SAC/a.sac - 1
    --------------------
    DEPMAX = 1.441192e+13
    DEPMIN = 7.639150e+07
    NVHDR = 7

    However, I give the following command
    message " max-min &1,DEPMAX &1,DEPMIN "
    max-min -2147483648 76391496

    The maximum number is not true, so I cannot normalize the data.
    The value of the &1,DEPMAX is the limit of 32bit-number (2^32)/2

    Do you have any suggestions?

    Best regards
    Onur Tan

    PS. Here is the sac binary
    bin> file sac
    sac: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically
    linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32,
    BuildID[sha1]=e8e1bcc88c9c35a7d485a1c78c1f93da6793deee, not s
    tripped




    ----------------------
    SAC Help
    Topic home: http://ds.iris.edu/message-center/topic/sac-help/ |
    Unsubscribe: sac-help-unsubscribe<at>lists.ds.iris.edu

    Sent from the IRIS Message Center (http://ds.iris.edu/message-center/)
    Update subscription preferences at http://ds.iris.edu/account/profile/


Page built 19:15:44 | v.b'59d0d2