Thread: Nested Variables in IF statement

Hi James,

Instead if you do:

do i list %list%
readhdr $i
if &1,delta& LT 0.05
message "$i$ is OK"
else
message "$i$ not OK"
endif
enddo

I works for me, and readhdr is appropriate to load only header in memory.

Cheers,

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 156 (Udine)
Tel: +39 040 2140 256 (Trieste)
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E-mail: mplasencia<at>inogs.it
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ASAIN (Antarctic Seismographic Argentinean Italian Network)
*********************************

On Sep 20, 2016, at 23:43, James Neely <neelyj<at>umich.edu> wrote:

Hi,
I'm running into a problem with nested variables in an IF statement. I want to check the sampling rate of the many SAC files and then perform an action based on whether that rate is above or below a reference value. I'm trying to use a DO loop to cycle through the files. However, when I call the macro variable $i inside the header variable, I get an error that it $i is an illegal file name. It looks like SAC is not reading the macro variable correctly. Any ideas on how I can get it to read the macro variable? Here is my script.

read $File
DO i list $File
IF &$i$,DELTA& < 0.05
MESSAGE "This needs to be resampled"
ELSE
MESSAGE "This one is ok"
ENDIF
ENDDO

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Dear James -

I suspect that you are using the IRIS version of SAC, which lacks some of the features described in the SAC book, in particular, the syntax embedding macro variables in file or blackboard variables. Here’s demonstration of the features using SAC/BRIS (terminology of section 1.5 in the SAC book):

#cat /tmp/mactest
fg seismogram
setbb list "/tmp/filea /tmp/fileb"
do i list %list%
w $i$
enddo

read %list%

do i list %list%
if &$i$,delta& LT 0.05
message "$i$ is OK"
else
message "$i$ isn't OK"
endif
enddo

#sac
SEISMIC ANALYSIS CODE [June 25 1991 (Version 10.6d-grh111/242)]
Copyright 1991 Regents of the University of California

SAC> echo on
SAC> m /tmp/mactest
m /tmp/mactest
fg seismogram
setbb list "/tmp/filea /tmp/fileb"
do i list %list%
==> do i list /tmp/filea /tmp/fileb
w $i$
==> w /tmp/filea
enddo
w $i$
==> w /tmp/fileb
enddo

read %list%
==> read /tmp/filea /tmp/fileb

do i list %list%
==> do i list /tmp/filea /tmp/fileb
if &$i$,delta& LT 0.05
==> if 0.10E-01 LT 0.05
message "$i$ is OK"
==> message "/tmp/filea is OK"
/tmp/filea is OK
else
endif
enddo
if &$i$,delta& LT 0.05
==> if 0.10E-01 LT 0.05
message "$i$ is OK"
==> message "/tmp/fileb is OK"
/tmp/fileb is OK
else
endif
enddo
SAC> quit
quit
#

On 21 Sep 2016, at 06:43, James Neely <neelyj<at>umich.edu> wrote:

Hi,
I'm running into a problem with nested variables in an IF statement. I want to check the sampling rate of the many SAC files and then perform an action based on whether that rate is above or below a reference value. I'm trying to use a DO loop to cycle through the files. However, when I call the macro variable $i inside the header variable, I get an error that it $i is an illegal file name. It looks like SAC is not reading the macro variable correctly. Any ideas on how I can get it to read the macro variable? Here is my script.

read $File
DO i list $File
IF &$i$,DELTA& < 0.05
MESSAGE "This needs to be resampled"
ELSE
MESSAGE "This one is ok"
ENDIF
ENDDO

----------------------
SAC Help (http://ds.iris.edu/message-center/topic/sac-help/)

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

George Helffrich
george<at>elsi.jp