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Re: positioning a TV image within plotting region [message #77868 is a reply to message #77830]

Fri, 30 September 2011 08:34

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

Matthew writes:

> position = [x0, y0, x1, y1] ;position in normal
> coordinates
> position[0] = floor(position[0] * !d.x_vsize)
> position[1] = floor(position[1] * !d.y_vsize)
> position[2] = floor(position[2] * !d.x_vsize)
> position[3] = floor(position[3] * !d.y_vsize)
> xsize = (position[2] - position[0]) - 1
> ysize = (position[3] - position[1]) - 1
> xstart = position[0] + 1
> ystart = position[1] + 1

I think these two lines:

> position[2] = floor(position[2] * !d.x_vsize)
> position[3] = floor(position[3] * !d.y_vsize)

should use CEIL instead of FLOOR.

But, I think this is essentially correct. I've changed
the way I calculate the image size and start positions
in cgImage this morning to this, and I like the results
very much.

; Calculate the image size and start locations.
xsize = Ceil((position[2] - position[0]) * !D.X_VSIZE)-1
ysize = Ceil((position[3] - position[1]) * !D.Y_VSIZE)-1
xstart = Round(position[0] * !D.X_VSIZE)+1
ystart = Round(position[1] * !D.Y_VSIZE)+1

You can test the "fit" by typing these commands and resizing
the window:

Loadct, 0, NColors=20
cgImage, BytScl(Dist(20), TOP=19), /Axes, /Keep, $
Background='sky blue', /Erase, /Window

Cheers,

David

--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.idlcoyote.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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[Message index]

		Re: positioning a TV image within plotting region By: David Fanning on Wed, 05 October 2011 11:06
		Re: positioning a TV image within plotting region By: Matthew on Wed, 05 October 2011 10:26
		Re: positioning a TV image within plotting region By: David Fanning on Fri, 30 September 2011 08:34
		Re: positioning a TV image within plotting region By: Matthew on Thu, 29 September 2011 12:19
		Re: positioning a TV image within plotting region By: greg michael on Thu, 29 September 2011 07:47
		Re: positioning a TV image within plotting region By: greg.addr on Thu, 29 September 2011 07:42
		Re: positioning a TV image within plotting region By: greg.addr on Thu, 29 September 2011 07:39
		Re: positioning a TV image within plotting region By: Matthew Argall on Mon, 10 October 2011 16:22

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