Thread: CUT problem

Dear Milton and Januka,

I hope this is informative.

The "CUT ON" command does not set the cut points; they default to a time
of 0.0. You should be using "CUT T0 T1" to specify the cut points.

%sac
SAC> fg seismo
SAC> ch t0 10
SAC> ch t1 14
SAC> w file.sac
SAC> report cut

CUT option is OFF
SAC> cut on
SAC> report cut

CUT option is ON
Start is 0
Stop is 0
SAC> r file.sac
WARNING: Start cut greater than stop cut for file file.sac
time: 0.000000 >= 0.000000
index: -945 >= -945
ERROR 1301: No data files read in.
SAC> cut t0 t1
SAC> report cut

CUT option is ON
Start is T0 0
Stop is T1 0
SAC> r file.sac
SAC> lh t0 t1 b e npts


FILE: file.sac - 1
--------------

t0 = 1.000000e+01
t1 = 1.400000e+01
b = 9.999999e+00
e = 1.400000e+01
npts = 401
SAC> q


Brian

On Jan 5, 2014, at 10:44 AM, Januka Attanayake wrote:

Thanks Milton, try quitting SAC and reading the file again. From my
experience, if you don't use CUT ON, the CUT is actually not done but stays
in memory and lost when you quit SAC.


On Sun, Jan 5, 2014 at 3:30 PM, Milton Plasencia <mpplasencia<at>gmail.com>wrote:

Hi Januka,


I use sac 101.6a (last version) on Mac OSX Mavericks.

So,

I try the following:
1) I use the the function generator command,

funcgen seismogram

here i have defined T0 and T1 markers.(e.g. T0 1, T1 6)
w aa.sac

2) if i use the cut on and read the aa.sac i see the same error,

But if i do:
r aa.sac
cut T0 T1
r
p
all is OK.

I not sure the "cut on" behavior when the file have T0 and T1 headers,
it is evident that "cut on" active the cut between T0 and T1, but the
file not "have" the points quantity to cut, so error.

Perhaps Arthur and Brian can give some light on the cut behavior.

HTH,

Milton

* * * * * * * * * * * * * * * * * * * * * * *
Milton P. PLASENCIA LINARES

Centro di Ricerche Sismologiche (CRS)
OGS - Istituto Nazionale di Oceanografia
e di Geofisica Sperimentale

Borgo Grotta Gigante 42/C
(34010) Sgonico - Trieste - Italia
Tel: +39 040 2140 141 (Udine)
Tel: +39 040 2140 256 (Trieste)
Cel.: +39 331 6481 935
Fax: +39-040-327307

E-mail: mplasencia<at>inogs.it

ASAIN (Antarctic Seismographic Argentinean Italian Network)
*********************************










On Jan 5, 2014, at 12:56 PM, Januka Attanayake <jattanayake<at>gmail.com>
wrote:

Hello,
I am trying to do a simple CUT on a collection of 21 seismograms. The
time stamps of T0 and T1 are placed using PPK. When I execute cut as
follows, however, I get an error.

SAC> CUT OFF
SAC> CUT ON
SAC> R CUT_GGNV_BHZ.SAC
WARNING: Start cut greater than stop cut for file CUT_GGNV_BHZ.SAC
time: 0.000000 >= 0.000000
index: 1 >= 1
ERROR 1301: No data files read in.

This doesn't make sense to me because clearly T0 < T1 for each and every
file. Also, I am not sure why SAC is trying to cut between T0 and T1 even
before I define the time window. For example,

SAC> R CUT_GGNV_BHZ.SAC
SAC> lh B T0 T1


FILE: CUT_GGNV_BHZ.SAC - 1
----------------------

B = 0.000000e+00
T0 = 1.013551e+03
T1 = 2.712720e+03

I am using a loop to read files one at a time and cut but in the above
example I just read one file as an illustration of my SAC issue. I tried
using CUTERR FILLZ option but the problem persists.

I am on MAC OS X (Mountain Lion) and using SAC version 101.6. I haven't
encountered this type of an error before with CUT in older versions of
SAC. Any help towards resolving this issue is much appreciated.

Januka.


--
Januka Attanayake
Postdoctoral Research Associate
Laboratório de Sismologia
Complexo Interdisciplinar
Departamento de Física
Instituto Superior Técnico
Av. Rovisco Pais, 1
1049-001 Lisboa, Portugal

University email: januka.attanayake<at>ist.utl.pt
Homepage: http://sites.google.com/site/janukaattanayake/
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--
Januka Attanayake
Postdoctoral Research Associate
Laboratório de Sismologia
Complexo Interdisciplinar
Departamento de Física
Instituto Superior Técnico
Av. Rovisco Pais, 1
1049-001 Lisboa, Portugal

University email: januka.attanayake<at>ist.utl.pt
Homepage: http://sites.google.com/site/janukaattanayake/
_______________________________________________
sac-help mailing list
sac-help<at>iris.washington.edu
http://www.iris.washington.edu/mailman/listinfo/sac-help