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Diplay 2D data [message #57095]

Tue, 04 December 2007 02:26

lasse
Messages: 48
Registered: February 2007

Member

Hi there,

in one of the recent posts there was a link to Brian Larsen's homepage
and in particular his imagesc.pro. This reminded me that I wanted to
ask a question related to the matter of image display with axes:

What's the best way to display 2D colour-coded data with axes and what-
not? Or rather, what do people out there use?

For a long time I used a routine called IMDISP which I downloaded
somewhere. It seems to be the same approach as Brian's, getting a 2D
array, using one of the TV commands to display it at a certain
position and the overplotting axes. I am not happy with that approach
because axes and image are completely unconnected, if I change the
axes ranges then I (or the display routine) needs to chop of bits of
the image array, otherwise the same image is displayed just with
different axes. More importantly, both mentioned routines cannot pad
zeros to the image such that the axis range is extended over the
extends of the image. This is important for me because I am anal and I
want my dynamic spectra plots to start at round times - but the data
doesn't. And also, since the pixels have finite dimensions, I really
also need to change the axes values to the exact position at the end
of the pixel.

This then led me to write my own routine which uses POLYFILL. So
basically every pixel is drawn as a filled polygon with a certain
colour. This allows me to easily (in my mind) change the ranges
without having to fiddle with the data.

However, not only is a FOR loop with POLYFILL slow but also a page of
three dynamic spectra with 8000x128 points now easily makes a 40MB
PostScript - not surprisingly, really.

So to get back to the original question: How do other people display
2D data?

Cheers
Lasse Clausen

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[Message index]

		Diplay 2D data By: lasse on Tue, 04 December 2007 02:26
		Re: Diplay 2D data By: lasse on Wed, 05 December 2007 01:05
		Re: Diplay 2D data By: pgrigis on Wed, 05 December 2007 11:23
		Re: Diplay 2D data By: Brian Larsen on Tue, 04 December 2007 12:52
		Re: Diplay 2D data By: pgrigis on Tue, 04 December 2007 12:43
		Re: Diplay 2D data By: Brian Larsen on Tue, 04 December 2007 12:13
		Re: Diplay 2D data By: wlandsman on Tue, 04 December 2007 11:12
		Re: Diplay 2D data By: lasse on Thu, 06 December 2007 02:36

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