| Re: Am I having a blackout? [message #66645] |
Fri, 29 May 2009 05:31 |
Brian Larsen
Messages: 270
Registered: June 2006
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Senior Member |
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I always have to remind myself each time exactly the right way to do
this but I am a big fan of reading in text files into a structure all
in one go.
Give something like this a try, for my brain this is the best way.
file='idl.dat'
lines=file_lines(file)
dat={date:0L, data:fltarr(5)}
dat=replicate(dat, lines)
openr, lun, file, /get_lun
readf, lun, dat
free_lun, lun
print, dat.date
; 20050206 20050207 20050402 20050411 20050421
20050422
; 20050423 20050614 20050618 20050619
print, dat.data[0]
; 0.386216 0.391236 0.685645 0.727419 0.768319
0.772067
; 0.775750 0.878818 0.879916 0.880047
Cheers,
Brian
------------------------------------------------------------ --------------
Brian Larsen
Boston University
Center for Space Physics
http://people.bu.edu/balarsen/Home/IDL
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| Re: Am I having a blackout? [message #66646 is a reply to message #66645] |
Fri, 29 May 2009 02:14  |
Allan Whiteford
Messages: 117
Registered: June 2006
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Senior Member |
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Mark wrote:
> Hi all,
>
> I'm trying to read a very simple file with very basic commands, but it
> reads the wrong values for the last variable (d2): readf does not see
> it are negative values and reads only the last five digits. The first
> five items it reads OK. I guess I'm making a very trivial mistake
> here, but I don't see it. Anyone having a clearer mind than me?
> Thanks!
>
> Mark
>
> sum1 = 0.0
> sum2 = 0.0
> sum3 = 0.0
> sum4 = 0.0
> count = 0
> dummy1=''
> openr, unit, /get_lun, 'sunny_days.fits'
> while ~eof(unit) do begin
> readf, unit, format='(A8,F,F,F,F,F)', dummy1, dummy2, A, beta, d1,
> d2
Mark,
My understanding of simply using 'F' as a format code doesn't mean "read
a floating point number in a smart way" it means "use the default values
for a floating point number". These are (according to the manual)
equivalent to 'F15.7'.
So, when you write:
format='(A8,F,F,F,F,F)'
this is equivalent to:
format='(A8,F15.7,F15.7,F15.7,F15.7,F15.7)',
A cursory glance at your file seems to explain what is happening, all
your whitespace are being slowly eaten until finally things go wrong at
the last column.
The behaviour of 'F' doesn't seem to be as useful as you would
reasonably expect it to be.
You probably want to use:
format='(A8,5F13)'
but when reading data in like this it's usually better not to supply a
format code at all - then IDL will try to do something smart for you
based on the types of variables you're using.
Thanks,
Allan
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| Re: Am I having a blackout? [message #66647 is a reply to message #66646] |
Fri, 29 May 2009 01:25 |
Mark[2]
Messages: 4
Registered: May 2009
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Junior Member |
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Hi Chris,
Thanks for replying. Thanks for your suggestion, but it's more a
matter of why this particular piece of code does not work as intended.
(And the first field is a date, which, I guess, can be more
appropriately stored in a string).
Well, a new day has begun, new chances...
Mark
On May 29, 7:27 am, rog...@googlemail.com wrote:
> On 28 Mai, 23:34, Mark <Mark.Saven...@gmail.com> wrote:
>
>
>
>> -> due to the line wraps the layout is somewhat disturbed: the d2 is
>> after the d1 and also the negative values are in fact after the other
>> items on the line.
>
>> On May 28, 11:27 pm, Mark <Mark.Saven...@gmail.com> wrote:
>
>>> Hi all,
>
>>> I'm trying to read a very simple file with very basic commands, but it
>>> reads the wrong values for the last variable (d2): readf does not see
>>> it are negative values and reads only the last five digits. The first
>>> five items it reads OK. I guess I'm making a very trivial mistake
>>> here, but I don't see it. Anyone having a clearer mind than me?
>>> Thanks!
>
>>> Mark
>
>>> sum1 = 0.0
>>> sum2 = 0.0
>>> sum3 = 0.0
>>> sum4 = 0.0
>>> count = 0
>>> dummy1=''
>>> openr, unit, /get_lun, 'sunny_days.fits'
>>> while ~eof(unit) do begin
>>> readf, unit, format='(A8,F,F,F,F,F)', dummy1, dummy2, A, beta, d1,
>>> d2
>>> help, dummy1, dummy2, A, beta, d1, d2
>>> sum1 += A
>>> sum2 += beta
>>> sum3 += d1
>>> sum4 += d2
>>> count++
>>> end
>>> print, sum1/count, sum2/count, sum3/count, sum4/count
>>> end
>
>>> part of sunny_days.fits:
>
>>> 20050206 0.386216 1286.08 1.34860 0.133876
>>> -0.695917
>>> 20050207 0.391236 1080.36 1.19682 0.285981
>>> -0.127826
>>> 20050402 0.685645 1137.82 1.20061 0.112449
>>> -0.716363
>>> 20050411 0.727419 1096.23 1.21388 0.134878
>>> -0.556709
>>> 20050421 0.768319 1110.19 1.19086 0.136384
>>> -0.636537
>>> 20050422 0.772067 1133.38 1.26480 0.214946
>>> -0.528211
>>> 20050423 0.775750 1115.85 1.26544 0.196289
>>> -0.642749
>>> 20050614 0.878818 1109.71 1.21778 0.140585
>>> -0.640095
>>> 20050618 0.879916 1055.35 1.16299 0.103695
>>> -0.706452
>>> 20050619 0.880047 1071.56 1.15538 0.0915420
>>> -0.690452
>
>>> Full file at:http://www.markjoe.com/tmp/sunny_days.fits-Zitierten Text ausblenden -
>
>> - Zitierten Text anzeigen -
>
> Dear Mark,
> no idea, what's going wrong there, but did you try the following?
>
> data=fltarr(6,file_lines('sunny_days.fits'),/nozero)
> openr, unit, /get_lun, 'sunny_days.fits'
> readf, unit, data
> free_lun, unit
> etc...
>
> Regards
> Chris
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| Re: Am I having a blackout? [message #66648 is a reply to message #66647] |
Fri, 29 May 2009 00:27 |
rogass
Messages: 200
Registered: April 2008
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Senior Member |
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On 28 Mai, 23:34, Mark <Mark.Saven...@gmail.com> wrote:
> -> due to the line wraps the layout is somewhat disturbed: the d2 is
> after the d1 and also the negative values are in fact after the other
> items on the line.
>
> On May 28, 11:27 pm, Mark <Mark.Saven...@gmail.com> wrote:
>
>
>
>> Hi all,
>
>> I'm trying to read a very simple file with very basic commands, but it
>> reads the wrong values for the last variable (d2): readf does not see
>> it are negative values and reads only the last five digits. The first
>> five items it reads OK. I guess I'm making a very trivial mistake
>> here, but I don't see it. Anyone having a clearer mind than me?
>> Thanks!
>
>> Mark
>
>> sum1 = 0.0
>> sum2 = 0.0
>> sum3 = 0.0
>> sum4 = 0.0
>> count = 0
>> dummy1=''
>> openr, unit, /get_lun, 'sunny_days.fits'
>> while ~eof(unit) do begin
>> readf, unit, format='(A8,F,F,F,F,F)', dummy1, dummy2, A, beta, d1,
>> d2
>> help, dummy1, dummy2, A, beta, d1, d2
>> sum1 += A
>> sum2 += beta
>> sum3 += d1
>> sum4 += d2
>> count++
>> end
>> print, sum1/count, sum2/count, sum3/count, sum4/count
>> end
>
>> part of sunny_days.fits:
>
>> 20050206 0.386216 1286.08 1.34860 0.133876
>> -0.695917
>> 20050207 0.391236 1080.36 1.19682 0.285981
>> -0.127826
>> 20050402 0.685645 1137.82 1.20061 0.112449
>> -0.716363
>> 20050411 0.727419 1096.23 1.21388 0.134878
>> -0.556709
>> 20050421 0.768319 1110.19 1.19086 0.136384
>> -0.636537
>> 20050422 0.772067 1133.38 1.26480 0.214946
>> -0.528211
>> 20050423 0.775750 1115.85 1.26544 0.196289
>> -0.642749
>> 20050614 0.878818 1109.71 1.21778 0.140585
>> -0.640095
>> 20050618 0.879916 1055.35 1.16299 0.103695
>> -0.706452
>> 20050619 0.880047 1071.56 1.15538 0.0915420
>> -0.690452
>
>> Full file at:http://www.markjoe.com/tmp/sunny_days.fits- Zitierten Text ausblenden -
>
> - Zitierten Text anzeigen -
Dear Mark,
no idea, what's going wrong there, but did you try the following?
data=fltarr(6,file_lines('sunny_days.fits'),/nozero)
openr, unit, /get_lun, 'sunny_days.fits'
readf, unit, data
free_lun, unit
etc...
Regards
Chris
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| Re: Am I having a blackout? [message #66650 is a reply to message #66648] |
Thu, 28 May 2009 14:34 |
Mark[2]
Messages: 4
Registered: May 2009
|
Junior Member |
|
|
-> due to the line wraps the layout is somewhat disturbed: the d2 is
after the d1 and also the negative values are in fact after the other
items on the line.
On May 28, 11:27 pm, Mark <Mark.Saven...@gmail.com> wrote:
> Hi all,
>
> I'm trying to read a very simple file with very basic commands, but it
> reads the wrong values for the last variable (d2): readf does not see
> it are negative values and reads only the last five digits. The first
> five items it reads OK. I guess I'm making a very trivial mistake
> here, but I don't see it. Anyone having a clearer mind than me?
> Thanks!
>
> Mark
>
> sum1 = 0.0
> sum2 = 0.0
> sum3 = 0.0
> sum4 = 0.0
> count = 0
> dummy1=''
> openr, unit, /get_lun, 'sunny_days.fits'
> while ~eof(unit) do begin
> readf, unit, format='(A8,F,F,F,F,F)', dummy1, dummy2, A, beta, d1,
> d2
> help, dummy1, dummy2, A, beta, d1, d2
> sum1 += A
> sum2 += beta
> sum3 += d1
> sum4 += d2
> count++
> end
> print, sum1/count, sum2/count, sum3/count, sum4/count
> end
>
> part of sunny_days.fits:
>
> 20050206 0.386216 1286.08 1.34860 0.133876
> -0.695917
> 20050207 0.391236 1080.36 1.19682 0.285981
> -0.127826
> 20050402 0.685645 1137.82 1.20061 0.112449
> -0.716363
> 20050411 0.727419 1096.23 1.21388 0.134878
> -0.556709
> 20050421 0.768319 1110.19 1.19086 0.136384
> -0.636537
> 20050422 0.772067 1133.38 1.26480 0.214946
> -0.528211
> 20050423 0.775750 1115.85 1.26544 0.196289
> -0.642749
> 20050614 0.878818 1109.71 1.21778 0.140585
> -0.640095
> 20050618 0.879916 1055.35 1.16299 0.103695
> -0.706452
> 20050619 0.880047 1071.56 1.15538 0.0915420
> -0.690452
>
> Full file at:http://www.markjoe.com/tmp/sunny_days.fits
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