| Re: character size in normal coordinates [message #13610] |
Tue, 24 November 1998 00:00 |
David Foster
Messages: 341
Registered: January 1996
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Senior Member |
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David Fanning wrote:
>
> David Foster (foster@bial1.ucsd.edu) writes:
>
>> Since !D.[X|Y]_CH_SIZE give the width and height of the rectangle
>> that encloses the "average" character in the current font, in
>> device units (usually pixels) [from the Online help on !D]:
>>
>> x_ch_norm = !D.X_CH_SIZE / !D.X_SIZE
>> y_ch_norm = !D.Y_CH_SIZE / !D.Y_SIZE
>>
>> would be my guess. If your window is 100 pixels wide, and your
>> object is 50 pixels wide, then in normalized coordinates that
>> would be .5 . Or am I having a bad hair day?
>
> I would say your hair will be turning prematurely gray
> unless you cast one of those values on the right-hand
> side of the equation to FLOAT. :-)
>
> Cheers,
>
> David
Doh!
God I hate this pitfall!
Dave
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~
David S. Foster Univ. of California, San Diego
Programmer/Analyst Brain Image Analysis Laboratory
foster@bial1.ucsd.edu Department of Psychiatry
(619) 622-5892 8950 Via La Jolla Drive, Suite 2240
La Jolla, CA 92037
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~
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| Re: character size in normal coordinates [message #13616 is a reply to message #13610] |
Mon, 23 November 1998 00:00  |
davidf
Messages: 2866
Registered: September 1996
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Senior Member |
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David Foster (foster@bial1.ucsd.edu) writes:
> Since !D.[X|Y]_CH_SIZE give the width and height of the rectangle
> that encloses the "average" character in the current font, in
> device units (usually pixels) [from the Online help on !D]:
>
> x_ch_norm = !D.X_CH_SIZE / !D.X_SIZE
> y_ch_norm = !D.Y_CH_SIZE / !D.Y_SIZE
>
> would be my guess. If your window is 100 pixels wide, and your
> object is 50 pixels wide, then in normalized coordinates that
> would be .5 . Or am I having a bad hair day?
I would say your hair will be turning prematurely gray
unless you cast one of those values on the right-hand
side of the equation to FLOAT. :-)
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438 E-Mail: davidf@dfanning.com
Coyote's Guide to IDL Progamming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155
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| Re: character size in normal coordinates [message #13617 is a reply to message #13616] |
Mon, 23 November 1998 00:00 |
David Foster
Messages: 341
Registered: January 1996
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Senior Member |
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Axel Schweiger wrote:
>
> How does one convert the character size into normal coordinates.
> --
> #----------------------------------------------------------- ------------------
> # Axel Schweiger
Since !D.[X|Y]_CH_SIZE give the width and height of the rectangle
that encloses the "average" character in the current font, in
device units (usually pixels) [from the Online help on !D]:
x_ch_norm = !D.X_CH_SIZE / !D.X_SIZE
y_ch_norm = !D.Y_CH_SIZE / !D.Y_SIZE
would be my guess. If your window is 100 pixels wide, and your
object is 50 pixels wide, then in normalized coordinates that
would be .5 . Or am I having a bad hair day?
Dave
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~
David S. Foster Univ. of California, San Diego
Programmer/Analyst Brain Image Analysis Laboratory
foster@bial1.ucsd.edu Department of Psychiatry
(619) 622-5892 8950 Via La Jolla Drive, Suite 2240
La Jolla, CA 92037
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~
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| Re: character size in normal coordinates [message #13619 is a reply to message #13616] |
Mon, 23 November 1998 00:00 |
Martin Schultz
Messages: 515
Registered: August 1997
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Senior Member |
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David Fanning wrote:
> Martin Schultz (mgs@io.harvard.edu) writes:
>
>> My guess would be :
>>
>> pixsize = !d.y_ch_size * !p.charsize ; or your own charsize --> gives
>> size in pixels
>> normsize = convert_coord(pixsize,/device,/to_normal)
>> UGLY! That doesn't work! Well, then
>> normsize = pixsize/!d.y_size
>
> Careful here. The expression:
>
> normsize = pixsize / !D.Y_Size
>
> is going to evaluation to 0, almost always. :-)
>
> Try:
>
> normsize = pixsize / Float(!D.Y_Size)
>
> This one has bit me enough that I almost always
> remember it. :-)
>
> Cheers,
>
> David
>
> --
> David Fanning, Ph.D.
> Fanning Software Consulting
> Phone: 970-221-0438 E-Mail: davidf@dfanning.com
> Coyote's Guide to IDL Progamming: http://www.dfanning.com/
> Toll-Free IDL Book Orders: 1-888-461-0155
Ouch !! But ... if you use !p.charsize you already have a float variable.
IDL> help,!p,/stru
[...]
CHARSIZE FLOAT 1.40000
[...]
Martin
--
------------------------------------------------------------ -------
Dr. Martin Schultz
Department for Engineering&Applied Sciences, Harvard University
109 Pierce Hall, 29 Oxford St., Cambridge, MA-02138, USA
phone: (617)-496-8318
fax : (617)-495-4551
e-mail: mgs@io.harvard.edu
Internet-homepage: http://www-as.harvard.edu/people/staff/mgs/
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| Re: character size in normal coordinates [message #13625 is a reply to message #13616] |
Sun, 22 November 1998 00:00 |
davidf
Messages: 2866
Registered: September 1996
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Senior Member |
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Martin Schultz (mgs@io.harvard.edu) writes:
> My guess would be :
>
> pixsize = !d.y_ch_size * !p.charsize ; or your own charsize --> gives
> size in pixels
> normsize = convert_coord(pixsize,/device,/to_normal)
> UGLY! That doesn't work! Well, then
> normsize = pixsize/!d.y_size
Careful here. The expression:
normsize = pixsize / !D.Y_Size
is going to evaluation to 0, almost always. :-)
Try:
normsize = pixsize / Float(!D.Y_Size)
This one has bit me enough that I almost always
remember it. :-)
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438 E-Mail: davidf@dfanning.com
Coyote's Guide to IDL Progamming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155
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| Re: character size in normal coordinates [message #13629 is a reply to message #13625] |
Sun, 22 November 1998 00:00 |
Martin Schultz
Messages: 515
Registered: August 1997
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Senior Member |
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Axel Schweiger wrote:
> How does one convert the character size into normal coordinates.
> --
> # Axel Schweiger
>
My guess would be :
pixsize = !d.y_ch_size * !p.charsize ; or your own charsize --> gives
size in pixels
normsize = convert_coord(pixsize,/device,/to_normal)
UGLY! That doesn't work! Well, then
normsize = pixsize/!d.y_size
[or maybe you'll have to use !d.x_ch_size and !d.x_size for better results ...]
Hope this gives you an idea at least,
Martin.
--
------------------------------------------------------------ -------
Dr. Martin Schultz
Department for Engineering&Applied Sciences, Harvard University
109 Pierce Hall, 29 Oxford St., Cambridge, MA-02138, USA
phone: (617)-496-8318
fax : (617)-495-4551
e-mail: mgs@io.harvard.edu
Internet-homepage: http://www-as.harvard.edu/people/staff/mgs/
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