| Re: HELP! Annoying IDL glitches... [message #6224 is a reply to message #6217] |
Thu, 16 May 1996 00:00   |
Robert Moss
Messages: 74
Registered: February 1996
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Member |
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I can answer a couple of these...
deb wrote:
>
> Here are some questions I'm hoping seasoned IDL users will be able to
> help me out with.
>
*snip*
>
> 3. Why does XYOUTS, when called with the keyword TEXT_AXES = 3
> rotate text such that it's mirror imaged of what one would expect for
> a regular y-axis label?
TEXT_AXES = 3 writes text as if the Y axis was the horizontal axis,
and the X axis was the vertical axis. I'm pretty sure thats why it
looks the way it does to you. You can use the ORIENTATION keyword
to flip it around if you want, of use a different value for TEXT_AXES.
Its all in the XYOUTS help file.
>
*snip*
>
> 5. Can one open a single (large) graphics window with scroll bars?
> (Not the same as the SLIDE_IMAGE command, but along the lines of the
> scroll window which is incorporated into that)
>
Piece of cake. Suppose you want a 1000x1000 window, with a 512x512
viewable area, with scroll bars. Try this:
base = widget_base()
draw = widget_draw( base, xsize = 1000, ysize = 1000, $
x_scroll_size = 512, y_scroll_size = 512 )
widget_control, base, /realize
widget_control, draw, get_value = win_num
wset, win_num
There you have it
> 6. Suppose one opens a datafile which contains an ascii header and then
*snip*
> work ok. When the binary junk is not stripped out, sometimes a STRPOS
> command finds the tag but frequently IDL chokes; when using a simple readf
> command,the error message says the input line is too long for the input
> buffer,
> even though it really isn't anywhere near 32767 characters long. Why?
> How does
> one get around this?
Well, the I/O buffer size is platform specific. For example, on
SunOS machines it defaults to 2048 bytes. From you comments I'd say
this is the root of your problem. All you need to do is use the BUFSIZ
keyword to OPENR, setting it to an appropriate large value:
OPENR, ilun, "foo.bar", BUFSIZ = 32767, /GET_LUN
As to your more general problem of finding the ASCII tag before your
data, I'm sure there are at least as many ways of doing this as there
are people to answer your question. I suggest reading the whole thing
in as a byte array (or some sufficiently large portion of it, if
reading the whole thing is unreasonable) and using the READS procedure
to parse it into whatever bits of whatever type you want.
>
> -Deb Summa
> summa@lanl.gov
Good luck. Feel free to contact me via email if you have any questions.
--
Robert M. Moss, Ph.D. - mossrm@texaco.com
------------------------------------------------------------ -
This does not necessarily reflect the opinions of Texaco Inc.
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