XinWang
(no body)
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I think there is something wrong with your file. I reproduced your result with v101.6, but when I included only the first 1000 values it worked okay. It looks like the only problem with interpolate is not finding and flagging the error. I will look more closely at your file, but I wanted to share this with you now.
Thank you for including the file test.ans.
Arthur
sac
SEISMIC ANALYSIS CODE [06/12/2013 (Version 101.6)]
Copyright 1995 Regents of the University of California
SAC> readtable content P test.ans
SAC> lh
FILE: test.ans - 1
--------------
NPTS = 2033 B = -8.520000e+01
E = 3.232471e+02 IFTYPE = TIME SERIES FILE
LEVEN = FALSE DEPMIN = -9.998000e-01
DEPMAX = 5.324000e-01 DEPMEN = -4.770257e-03
LOVROK = TRUE NVHDR = 6
LPSPOL = FALSE LCALDA = TRUE
SAC> interpolate delta 0.2
SAC> lh
FILE: test.ans - 1
--------------
NPTS = 2042 B = -8.520000e+01
E = 3.230000e+02 IFTYPE = TIME SERIES FILE
LEVEN = TRUE DELTA = 2.000000e-01
DEPMIN = -1.621000e-01 DEPMAX = nan
DEPMEN = nan LOVROK = TRUE
NVHDR = 6 LPSPOL = FALSE
LCALDA = TRUE
SAC> quit
The nan is probably what you got and is clearly wrong.
head -1000 test.ans > test1000.ans
SAC> readtable content P test1000.ans
SAC> lh
FILE: test1000.ans - 1
------------------
NPTS = 1000 B = -8.520000e+01
E = 1.151752e+02 IFTYPE = TIME SERIES FILE
LEVEN = FALSE DEPMIN = -9.998000e-01
DEPMAX = 5.324000e-01 DEPMEN = -6.679517e-03
LOVROK = TRUE NVHDR = 6
LPSPOL = FALSE LCALDA = TRUE
SAC> interpolate delta 0.2
SAC> lh
FILE: test1000.ans - 1
------------------
NPTS = 1002 B = -8.520000e+01
E = 1.150000e+02 IFTYPE = TIME SERIES FILE
LEVEN = TRUE DELTA = 2.000000e-01
DEPMIN = -9.998001e-01 DEPMAX = 5.324001e-01
DEPMEN = -7.755071e-03 LOVROK = TRUE
NVHDR = 6 LPSPOL = FALSE
LCALDA = TRUE
SAC> quit
On Aug 1, 2013, at 4:11 AM, wangxin wrote:
Dear,
When I was trying to use SAC to interpolate unevenly-spaced data to evenly-spaced data, I got a trouble.
("test.ans" is my unevenly-spaced data.)
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Dear Wangxin,
Your file has a duplicate time value
% awk '{print $1}' test.ans | sort | uniq -d
243.6050
% grep 243.6050 test.ans
243.6050 -0.1160
243.6050 -0.1193
The unevenly spaced interpolation routine should handle this properly, but does not. The routine relies on the computation of slope dy/dt and if the time value between your points is zero, the slope and all values derived from the slope become inf or nan. This includes the interpolated amplitude.
We will work on a fix for this. An easy, but non optimal, fix for this is to average your duplicate points.
Brian
On Aug 2, 2013, at 9:33 AM, Arthur Snoke wrote:
I think there is something wrong with your file. I reproduced your result with v101.6, but when I included only the first 1000 values it worked okay. It looks like the only problem with interpolate is not finding and flagging the error. I will look more closely at your file, but I wanted to share this with you now.
Thank you for including the file test.ans.
Arthur
sac
SEISMIC ANALYSIS CODE [06/12/2013 (Version 101.6)]
Copyright 1995 Regents of the University of California
SAC> readtable content P test.ans
SAC> lh
FILE: test.ans - 1
--------------
NPTS = 2033 B = -8.520000e+01
E = 3.232471e+02 IFTYPE = TIME SERIES FILE
LEVEN = FALSE DEPMIN = -9.998000e-01
DEPMAX = 5.324000e-01 DEPMEN = -4.770257e-03
LOVROK = TRUE NVHDR = 6
LPSPOL = FALSE LCALDA = TRUE
SAC> interpolate delta 0.2
SAC> lh
FILE: test.ans - 1
--------------
NPTS = 2042 B = -8.520000e+01
E = 3.230000e+02 IFTYPE = TIME SERIES FILE
LEVEN = TRUE DELTA = 2.000000e-01
DEPMIN = -1.621000e-01 DEPMAX = nan
DEPMEN = nan LOVROK = TRUE
NVHDR = 6 LPSPOL = FALSE
LCALDA = TRUE
SAC> quit
The nan is probably what you got and is clearly wrong.
head -1000 test.ans > test1000.ans
SAC> readtable content P test1000.ans
SAC> lh
FILE: test1000.ans - 1
------------------
NPTS = 1000 B = -8.520000e+01
E = 1.151752e+02 IFTYPE = TIME SERIES FILE
LEVEN = FALSE DEPMIN = -9.998000e-01
DEPMAX = 5.324000e-01 DEPMEN = -6.679517e-03
LOVROK = TRUE NVHDR = 6
LPSPOL = FALSE LCALDA = TRUE
SAC> interpolate delta 0.2
SAC> lh
FILE: test1000.ans - 1
------------------
NPTS = 1002 B = -8.520000e+01
E = 1.150000e+02 IFTYPE = TIME SERIES FILE
LEVEN = TRUE DELTA = 2.000000e-01
DEPMIN = -9.998001e-01 DEPMAX = 5.324001e-01
DEPMEN = -7.755071e-03 LOVROK = TRUE
NVHDR = 6 LPSPOL = FALSE
LCALDA = TRUE
SAC> quit
On Aug 1, 2013, at 4:11 AM, wangxin wrote:
Dear,
_______________________________________________
When I was trying to use SAC to interpolate unevenly-spaced data to evenly-spaced data, I got a trouble.
("test.ans" is my unevenly-spaced data.)
sac-help mailing list
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Arthur Snoke
Brian Savage
