[Kst] Image data type
netterfield at astro.utoronto.ca
Wed Jul 21 19:53:03 CEST 2004
Comments to this, and to other traffic on this topic...
-I thought I sent out an email about 3d plotting a month or so ago, but I
can't find it. Did I? Have you looked at it?
Sumary from memory:
-'Images' are function surfaces. They might be represented in two ways:
i) Z(x0 + i*dx, y0 + j*dy) (ie, in a regular grid)
ii) Z(x[i], y[i]) (ie, 3 vectors not necessarily on a grid)
Supporting (ii) from the file level will be very handy, but requires some sort
of binning policy. (i) is easy and relatively policy free, but not as
I can think of three main ways to show an 'image':
(i) Color map (as noted, 24 bits are probably required)
(ii) contour plot
(iii) rotatable surface plot
(i) and (ii) are both 2D objects and could/should be plotted in a kst2d plot,
because they share the same zoom actions, and could naturally be expected to
be plotted beneath regular curves. I agree that they should be connected to
kst2dplot as an analog to curves.
(iii) is a 3d object which will be presented in kst3d plot.
I am *very* hesitant to start down this path now. There is a lot to consider
and get right, and I would much rather have us focusing on a high quality 1.0
release! But.... if you are sure you can do this without jeprodizing 1.0....
perhaps (gulp!) Can you have something mainly working in 1 week?
On July 20, 2004 02:00 pm, Rick Chern wrote:
> I am currently working on an Image data type. Description of images:
> - images will be specified by three vectors, representing x, y, and z
So you intend to support un-gridded data.... What is your binning policy going
to be? What do you do about over-sampled maps? about undersampled maps?
How will you decide on gid density?
> - it is up to the user to make sure the three vectors selected make
> sense as an image
What does this mean?
> - images will be plotted on the 2D plot, using colours/shades to represent
> z - only 1 image can be plotted per plot
What will the colour-scale interface be? Also, one might want to show
multiple images covering different parts of the XY space, or to have a colour
map under a contour plot. So I wouldn't limit to one image per plot.
> - images will be plotted underneath any curves
> - images will appear as new data objects in the data manager
> Changes I would make:
> - create a KstImage class inheriting from KstDataObject (not KstBaseCurve)
> - add Image button to the New section of data manager
> - modify plot dialog slightly to be able to select 1 image (or not)
or more than one? I would just list the images with the curves.
> - create an image New/Edit dialog
> - make changes to Kst2DPlot to set, remove, and plot the image, if the
> plot has one
> I just wanted to check to be aware of any problems before I went to far
> - some of the changes have been made, but not committed yet.
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