| Re: reading large multicolumn data file [message #72128] |
Fri, 06 August 2010 11:22 |
bio_amateur
Messages: 7
Registered: August 2010
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Junior Member |
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On Aug 6, 11:17 am, David Fanning <n...@dfanning.com> wrote:
> David Fanning writes:
>> Free_Lun, data
>
> Whoops! That's not likely to work. :-(
>
> Try, "Free_Lun, lun"
>
> Cheers,
>
> David
>
> --
> David Fanning, Ph.D.
> Fanning Software Consulting, Inc.
> Coyote's Guide to IDL Programming:http://www.dfanning.com/
> Sepore ma de ni thui. ("Perhaps thou speakest truth.")
It works. Many thanks for this powerful package, David.
Tuan.
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| Re: reading large multicolumn data file [message #72133 is a reply to message #72132] |
Fri, 06 August 2010 07:46  |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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bio_amateur writes:
> Now, plotting is pretty fast. However, data reading is still slow,
> compared to xmgrace. Is there a better way than using the 2 steps:
> read the data into a structure, and convert a structure to an array as
> the way I did.
>
> The second question is xmgrace autoamtically choose one color for each
> data field (Y1, Y2, ...). However, with direct graphics in IDL, I only
> get one single color. How could we resolve this in IDL.
I'd try something like this:
rows = File_Lines(filename)
data = FltArr(4, rows)
Openr, lun, filename, /Get_Lun
ReadF, lun, data
Free_Lun, data
data = Transpose(data)
colors = ['black', 'white', 'red', 'green', 'blue']
Plot, data[*,0], data[1,*], Background=FSC_Color(colors[1]), $
Color=FSC_Color(colors[0]), /NoData
FOR j=1,3 DO OPlot, data[*,0], data[*,j], COLOR=FSC_Color(colors[j+1])
You can find FSC_Color in the Coyote Library:
http://www.dfanning.com/documents/programs.html
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")
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| Re: reading large multicolumn data file [message #72135 is a reply to message #72133] |
Fri, 06 August 2010 07:23 |
bio_amateur
Messages: 7
Registered: August 2010
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Junior Member |
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On Aug 5, 11:05 pm, Paulo Penteado <pp.pente...@gmail.com> wrote:
> On Aug 5, 8:54 pm, bio_amateur <hoangtrongminht...@gmail.com> wrote:
>
>
>
>> I have a data file (a few hundreds MB). This is a text file in the
>> format X Y1 Y2 Y3 (first column is the common x-axis data, next
>> columns are data). I can read the data and plot easily with xmgrace
>> using
>
>> xmgrace -nxy data.dat
>
>> which take a few seconds to plot. Now, I want to use IDL to read this
>> file and display using iTool. What I did was
>
>> data = read_ascii(filename)
>> myPlotData = data.(0)
>> rows = (size(myPlotData, /dimension))[0]
>> for ii=1, rows do begin
>> iPlot, myPlotData[0,*], myPlotData[ii,*], /overplot
>> end
>
>> This method takes so long. Could someone good at this can point out a
>> solution for me.
>
> The iTools, as any use of object graphics, can get heavy in memory
> when the number of vertices is large (typically, from several hundred
> thousand). This may be alleviated if change your IDL preferences to
> use hardware rendering, in case it is not already in hardware. Other
> than that, only using direct graphics will solve it, as in
>
> minx=min(myplotdata[0,*],max=maxx)
> miny=min(myplotdata[1:*,*],max=maxy)
>
> plot,[minx,maxx],[miny,maxy],/nodata
> for ii=1,rows-1 do oplot,myplotdata[0,*],myplotdata[ii,*]
Now, plotting is pretty fast. However, data reading is still slow,
compared to xmgrace. Is there a better way than using the 2 steps:
read the data into a structure, and convert a structure to an array as
the way I did.
The second question is xmgrace autoamtically choose one color for each
data field (Y1, Y2, ...). However, with direct graphics in IDL, I only
get one single color. How could we resolve this in IDL.
Thanks,
Tuan
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| Re: reading large multicolumn data file [message #72136 is a reply to message #72135] |
Fri, 06 August 2010 07:23 |
bio_amateur
Messages: 7
Registered: August 2010
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Junior Member |
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On Aug 5, 11:05 pm, Paulo Penteado <pp.pente...@gmail.com> wrote:
> On Aug 5, 8:54 pm, bio_amateur <hoangtrongminht...@gmail.com> wrote:
>
>
>
>> I have a data file (a few hundreds MB). This is a text file in the
>> format X Y1 Y2 Y3 (first column is the common x-axis data, next
>> columns are data). I can read the data and plot easily with xmgrace
>> using
>
>> xmgrace -nxy data.dat
>
>> which take a few seconds to plot. Now, I want to use IDL to read this
>> file and display using iTool. What I did was
>
>> data = read_ascii(filename)
>> myPlotData = data.(0)
>> rows = (size(myPlotData, /dimension))[0]
>> for ii=1, rows do begin
>> iPlot, myPlotData[0,*], myPlotData[ii,*], /overplot
>> end
>
>> This method takes so long. Could someone good at this can point out a
>> solution for me.
>
> The iTools, as any use of object graphics, can get heavy in memory
> when the number of vertices is large (typically, from several hundred
> thousand). This may be alleviated if change your IDL preferences to
> use hardware rendering, in case it is not already in hardware. Other
> than that, only using direct graphics will solve it, as in
>
> minx=min(myplotdata[0,*],max=maxx)
> miny=min(myplotdata[1:*,*],max=maxy)
>
> plot,[minx,maxx],[miny,maxy],/nodata
> for ii=1,rows-1 do oplot,myplotdata[0,*],myplotdata[ii,*]
Now, plotting is pretty fast. However, data reading is still slow,
compared to xmgrace. Is there a better way than using the 2 steps:
read the data into a structure, and convert a structure to an array as
the way I did.
The second question is xmgrace autoamtically choose one color for each
data field (Y1, Y2, ...). However, with direct graphics in IDL, I only
get one single color. How could we resolve this in IDL.
Thanks,
Tuan
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| Re: reading large multicolumn data file [message #72143 is a reply to message #72136] |
Thu, 05 August 2010 20:05 |
penteado
Messages: 866
Registered: February 2018
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Senior Member
Administrator |
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On Aug 5, 8:54 pm, bio_amateur <hoangtrongminht...@gmail.com> wrote:
> I have a data file (a few hundreds MB). This is a text file in the
> format X Y1 Y2 Y3 (first column is the common x-axis data, next
> columns are data). I can read the data and plot easily with xmgrace
> using
>
> xmgrace -nxy data.dat
>
> which take a few seconds to plot. Now, I want to use IDL to read this
> file and display using iTool. What I did was
>
> data = read_ascii(filename)
> myPlotData = data.(0)
> rows = (size(myPlotData, /dimension))[0]
> for ii=1, rows do begin
> iPlot, myPlotData[0,*], myPlotData[ii,*], /overplot
> end
>
> This method takes so long. Could someone good at this can point out a
> solution for me.
The iTools, as any use of object graphics, can get heavy in memory
when the number of vertices is large (typically, from several hundred
thousand). This may be alleviated if change your IDL preferences to
use hardware rendering, in case it is not already in hardware. Other
than that, only using direct graphics will solve it, as in
minx=min(myplotdata[0,*],max=maxx)
miny=min(myplotdata[1:*,*],max=maxy)
plot,[minx,maxx],[miny,maxy],/nodata
for ii=1,rows-1 do oplot,myplotdata[0,*],myplotdata[ii,*]
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