| Re: Format strings with comma separated lists [message #15353] |
Tue, 11 May 1999 00:00 |
Martin Schultz
Messages: 515
Registered: August 1997
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Senior Member |
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Vapuser wrote:
>
> Well, am I'm surprised!
>
> [...]
> Apparently, the short answer is you don't need to use format strings
> on input, provided, I guess, the data is homogeneous and with a
> constant number of columns(?); IDL understands that you don't want the
> comma.
Here is an example of why I am really glad that IDL does support format
strings:
23.4 12.2 12.1 10.0
56.4 98.4103.2143.9
200.2232.8165.1 99.7
AND believe it or not: those files exist and there are plenty of them
;-)
Also: format strings are probably the easiest way to (safely) convert a
file that is written in e.g. 60 lines with 8 numbers per line to an
array
of (40,12) [it's just one statement!]
Martin.
puhuu. didn't know that i am that old - i know something about format !
--
|||||||||||||||\\\\\\\\\\\\\-------------------///////////// //|||||||||||||||
Martin Schultz, DEAS, Harvard University, 29 Oxford St., Pierce 109,
Cambridge, MA 02138 phone (617) 496 8318 fax (617) 495 4551
e-mail mgs@io.harvard.edu web http://www-as/people/staff/mgs/
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| Re: Format strings with comma separated lists [message #15369 is a reply to message #15353] |
Mon, 10 May 1999 00:00  |
davidf
Messages: 2866
Registered: September 1996
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Senior Member |
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William Daffer (vapuser@catspaw.jpl.nasa.gov) writes:
> Apparently, the short answer is you don't need to use format strings
> on input, provided, I guess, the data is homogeneous and with a
> constant number of columns(?); IDL understands that you don't want the
> comma.
Uh, this has been a feature of IDL since...well, since
version 1.0, I believe. ;-)
Cheers,
David
P.S. Ain't IDL grand!? Hardly a week goes by I don't
learn something new about it. :-)
--
David Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438 E-Mail: davidf@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155
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| Re: Format strings with comma separated lists [message #15371 is a reply to message #15369] |
Mon, 10 May 1999 00:00 |
Vapuser
Messages: 63
Registered: November 1998
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Member |
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Well, am I'm surprised!
Just for a lark, I tried this
IDL> openw,1,'/tmp/delme.junk'
IDL> v=findgen(20)
IDL> printf,1,v,format='(4(f5.2,:,","))'
(NB, this comes out looking like
0.00, 1.00, 2.00, 3.00,
4.00, 5.00, 6.00, 7.00,
8.00, 9.00,10.00,11.00,
12.00,13.00,14.00,15.00,
16.00,17.00,18.00,19.00 )
IDL> close,1
IDL> openr,1,'/tmp/delme.junk'
IDL> v[*]=0
IDL> print,minmax(v)
0.00000 0.00000
IDL> v=reform(v,4,5)
IDL> help,v
V FLOAT = Array[4, 5]
IDL> readf,1,v
IDL> print,v
0.00000 1.00000 2.00000 3.00000
4.00000 5.00000 6.00000 7.00000
8.00000 9.00000 10.0000 11.0000
12.0000 13.0000 14.0000 15.0000
16.0000 17.0000 18.0000 19.0000
; Or, you can read it into a vector
IDL> v=fltarr(20)
IDL> point_lun,1,0
IDL> readf,1,v
IDL> print,v
0.00000 1.00000 2.00000 3.00000 4.00000 5.00000
6.00000 7.00000 8.00000 9.00000 10.0000 11.0000
12.0000 13.0000 14.0000 15.0000 16.0000 17.0000
18.0000 19.0000
IDL>
Apparently, the short answer is you don't need to use format strings
on input, provided, I guess, the data is homogeneous and with a
constant number of columns(?); IDL understands that you don't want the
comma.
You can even read the data if there isn't a constant number of
columns. I edited the file so that it looked like;
0.00, 1.00, 2.00,
4.00, 5.00, 6.00, 7.00,
8.00, 9.00,10.00,11.00,
12.00,13.00,14.00,15.00,
16.00,17.00,18.00,19.00
and read it with;
IDL> v=fltarr(19)
IDL> readf,1,v
IDL> print,v
0.00000 1.00000 2.00000 4.00000 5.00000 6.00000
7.00000 8.00000 9.00000 10.0000 11.0000 12.0000
13.0000 14.0000 15.0000 16.0000 17.0000 18.0000
19.0000
IDL>
I was going to suggest a combination of string reads and
STR_SEP. Doesn't look like you need it.
(By the was, this is a
IDL> print,!version
{ mipseb IRIX unix 5.1.1 Jul 20 1998} system
)
William
philaldis@geocities.com (Phil Aldis) writes:
> I hoping that someone else understands format strings better than I
> do, because I can't get them to work at all. I was wondering if anyone
> knew how to read a comma delimited list using format strings, such as
>
> Readf, lun, variable, FORMAT='(n(F6.6, :, ","))'
>
> ...this is the way I would think that you should do it but this just
> tells me that end of input record encountered.
>
> Does anyone know how to do it?#
>
> Cheers,
> Phil Aldis
--
William Daffer: 818-354-0161: vapuser@catspaw.jpl.nasa.gov
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| Re: Format strings with comma separated lists [message #15374 is a reply to message #15369] |
Mon, 10 May 1999 00:00 |
gurman
Messages: 82
Registered: August 1992
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Member |
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In article <3736bb88.14638556@146.80.9.44>, philaldis@geocities.com wrote:
> I hoping that someone else understands format strings better than I
> do, because I can't get them to work at all. I was wondering if anyone
> knew how to read a comma delimited list using format strings, such as
>
> Readf, lun, variable, FORMAT='(n(F6.6, :, ","))'
>
> ...this is the way I would think that you should do it but this just
> tells me that end of input record encountered.
>
> Does anyone know how to do it?#
>
> Cheers,
> Phil Aldis
Phil -
I believe this takes someone old enough to have learned programming
first in FORTRAN....
For formatted reads, you basically want to include only variable
descriptors and spaces (nX), so the colon and "," are counterproductive.
Have you tried something of the form:
IDL> READF, lun, variable, FORMAT = '$(n(f6.6, 2x))
That is, you just want to skip the commas and read the floating-point
variables.
Hope this is what you're looking for.
Joe Gurman
--
Joseph B. Gurman / NASA Goddard Space Flight Center / Solar Physics Branch /
Greenbelt MD 20771 / work: gurman@gsfc.nasa.gov /other: gurman@ari.net
Government employees are still not allowed to hold opinions while at work,
so any opinions expressed herein must be someone else's.
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