Started: 2005-11-11 22:02:29
Last activity: 2005-11-11 22:02:29
Topics: SAC Help
Hi Carlos (cpena<at>email.arizona.edu)-
Did you read ac_new.dat using the RA command in a linux version ofNo, I performed this operation on a Mac.
Before I tried your scheme, I just tried to read the file you createdNot sure why this happens on the Linux machine. The text file has New
and SAC responds with "WARNING: Trouble reading line. Skipping ...
(list of 5
column data points)"; one message per row of data points, and after it
with the warning messages it states "Segmentation fault" and proceeds
to kick me
out of SAC. The same thing happended to me when I tried to read one
Line characters for line terminators and I would think it would work
fine on a Linux box.
Moreover, when I convert a SAC format data file to an ALPHA formatNot sure of the reasons for this. Might be worth trying
the resulting data file is all "screwed up". SAC changes all the header
information and considers only a fraction of the data points. You can
by doing FG SEISMOGRAM and converting the resulting data file from SAC
space-separated data fields instead of tabs. I was taking a first
guess at a solution.
Could there be a bug in the linux version of SAC?; other people I'veI have no idea if there is a bug with the Linux version. We don't yet
tried it in a MAC version, using RA on one column data and no header
it worked OK.
have good tabulation of known issues for SAC here at IRIS (as far as I
am aware). I think it may be that the Mac-created text file
By the way, since you got it to plot, can you send me the rawThis is something I don't have experience with or the time to work
series plot, followed by a filtered acceleration, velocity and
time series plots?. Consider a 4th degree Butterworth low pass filter
lowcut at 4 Hz to filter raw acceleration points and a 4th degree
high pass filter with a high cut at 2 Hz for velocity and displacement
series. Please normalize acceleration time series with respect to the
BEFORE you apply filter and also normalize with respect to mean
displacement time series AFTER you apply the filter.
with. Perhaps a more SAC-inclined user can step in and help you with
your processing issue. (anyone?) I was trying to demonstrate that
through a UNIX shell it is not difficult to convert a single column of
text data to five columns of data. Beyond this, it's getting out of my
depth to manage in a time-effective manner.