comp.lang.idl-pvwave archive: archive » IDL objects (not object graphics) tutorial?

Home » Public Forums » archive » IDL objects (not object graphics) tutorial?

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: IDL objects (not object graphics) tutorial? [message #46611 is a reply to message #46457]

Fri, 02 December 2005 08:30

Paul Van Delst[1]
Messages: 1157
Registered: April 2002

Senior Member

David Fanning wrote:
> Paul Van Delst writes:
>
>
>> Your webpage is great! The one new thing I learned:
>>
>> self.ptr=ptr_new(/allocate)
>>
>> can be used to subsequently point to anything without further allocation!? E.g. from your
>> tutorial:
>>
>> a->set,image
>> or
>> a->set,!d
>>
>> where in the set method, the value is simply assigned:
>> *(self.ptr)=value
>>
>> Excuse my brain-deadedness, but how is this possible? I looked at the IDL docs but there
>> is (surprise, surprise) no elaboration about this little nugget of information regarding
>> PTR_NEW. Wouldn't susbsequent calls like the above cause a memory leak, e.g.
>>
>> IDL> image=findgen(512,512)
>> IDL> a=obj_new('data') ;-- create object variable a
>> IDL> a->set,image ;-- insert image
>> IDL> a->set,!d
>>
>> What would happen to the "image" data?
>
>
> The deep answers are all contained in the Pointer Tutorial:
>
> http://www.dfanning.com/misc_tips/pointers.html

Ahhh! It's just like a regular IDL variable. D'oh! - now why didn't assume that to be the
case in the first place?!

Very cool. I was treating this sort of thing like I do in Fortran95 where the pointers are
typed (i.e. they can only point to certain data types, kinds, and ranks) and that leads to
a lot of code bloat.

This changes everything. <monty>Excellent</monty> :o)

paulv

--
Paul van Delst
CIMSS @ NOAA/NCEP/EMC

Report message to a moderator

[Message index]

		IDL objects (not object graphics) tutorial? By: Richard French on Wed, 23 November 2005 18:33
		Re: IDL objects (not object graphics) tutorial? By: b_gom on Thu, 24 November 2005 01:04
		Re: IDL objects (not object graphics) tutorial? By: Paul Van Delst[1] on Fri, 02 December 2005 08:30
		Re: IDL objects (not object graphics) tutorial? By: David Fanning on Fri, 02 December 2005 08:11
		Re: IDL objects (not object graphics) tutorial? By: Paul Van Delst[1] on Fri, 02 December 2005 07:46
		Re: IDL objects (not object graphics) tutorial? By: Richard French on Wed, 30 November 2005 18:36
		Re: IDL objects (not object graphics) tutorial? By: dzarro on Tue, 29 November 2005 20:20

Previous Topic:	map_proj_inverse and map_proj_init IDL 6.2
Next Topic:	Data General Floating Point format?

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Wed Oct 08 19:59:27 PDT 2025

Total time taken to generate the page: 0.00455 seconds