| Re: contour & why pv-wave? [message #1362] |
Wed, 03 November 1993 08:46 |
paul
Messages: 22
Registered: June 1991
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Junior Member |
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In article <2b438m$94q@tali.hsc.colorado.edu>, mtadams@news.Colorado.EDU (Matthew T. Adams) writes:
> Hi all,
>
> I was wondering 2 things:
>
> 1) I've had to hack a bit around the contour procedure. Is there a contour
> *function* that will return to me an array of contour points or a structure that
> has contour headers and points (without my having to write the points to a file &
> then read the file (this was my hack))?
In IDL, use
contour, data, PATH_FILENAME=file_name, . . .
This writes the each contour path to the data file, and can be
read back in. The IDL Reference Guide for Version 3.1 describes this
on page 1-48. NOTE: The was tye data is written to the file
changed in release 3.1!!! so routines are not backward compatible.
It caused us more grief than it seems worth.
Also consider the /CLOSE parameter if you are trying to fill
contours. There is a bug in 3.1 which sometimes puts the wrong
value into the HIGH value of the contour_header. (3.5beta works
much better).
Once the data file is created, it can be read in with
openr, iu , file_name , /GET_LUN
hdr = {contour_header, type:0B, high:0B, level:0, num:0, value:0.0 }
release = FLOAT(!Version.release)
while not EOF(iu) begin
readu, iu, hdr
if ( release ge 3.1 ) then begin
x = fltarr( hdr.num )
y = fltarr( hdr.num )
readu, iu, x,y
endif else begin
d = fltarr( 2, hdr.num)
readu, iu, d
x = reform( d(0,*) )
y = reform( d(1,*) )
endelse
; The x and y values are in normalized coordinates
end
>
> 2) Is PV Wave a subset of IDL functions, or is it its own product? What does it
> have to do with IDL? Does it share the syntax or something?
>
> thanks,
>
> matthew
>
> ____________________
> mtadams@columbine.hsc.colorado.edu
> Matthew T. Adams
> University of Colorado Health Sciences Center
> Denver, CO
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| Re: contour & why pv-wave? [message #1364 is a reply to message #1362] |
Wed, 03 November 1993 07:05  |
thompson
Messages: 584
Registered: August 1991
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Senior Member |
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mtadams@news.Colorado.EDU (Matthew T. Adams) writes:
> 2) Is PV Wave a subset of IDL functions, or is it its own product? What does it
> have to do with IDL? Does it share the syntax or something?
At one time PV-Wave and IDL were the same product. IDL was developed by
Research Systems, Inc. At one point RSI entered into a contract with Precision
Visuals to market IDL under the name PV-Wave. Apparently part of this contract
gave Precision Visuals (now Visual Numerics) the right to buy out the source
code and go off on their own. So now IDL and PV-Wave are now separate and
competitive products with a common heritage. Each has been substantially
augmented since then. A lot of things, like the basic command syntax, are the
same for the two products (a lot of procedures can be used in both with little
or no modification), but a significant fraction, such as widget support, are
different because they were added or modified after the split.
This is all explained in gory detail in the FAQ which is posted once a month.
Bill
P.S. I tried to do a direct reply, but it didn't go through for some reason.
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