| Locating IDL source code file [message #44420] |
Tue, 14 June 2005 04:52  |
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Craig[1]
Messages: 8
Registered: June 2005
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Junior Member |
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[copied over from comp.lang.idl - don't know how to properly cross-post
it in retrospect using Google groups]
Hi all,
I'm trying to write some code that will read information (like version
numbers and dates) from the source files for procedures and functions
that it uses. In Matlab I would use a command like
>> which fred
to return the full path to the source file "fred.m". How do I get the
same result from IDL v6.1? I've tried something like
IDL> ttt = file_which('fred.pro', /include_current_dir)
but just got a null string returned. This might be because I'm using
the IDLDE, so the routine isn't actually on the search path !PATH, even
though it has been compiled OK when building the project.
Once this problem is solved, I'll also need to determine the filename
for the source file containing a definition of 'fred', because most of
the routines in this project don't have their own 'fred.pro' source
file.
Any ideas?
TIA,
Craig
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| Re: Locating IDL source code file [message #44485 is a reply to message #44420] |
Wed, 15 June 2005 03:24  |
Craig[1]
Messages: 8
Registered: June 2005
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Junior Member |
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Mark and Bob,
Thanks for your comments. I agree that having separate source files for
each routine would be nicer (and this is what I do in Matlab, for
example), but I'm working with code from somebody else, trying to
minimize the changes to the original code while writing something else
around it. I have had issues with the ordering of source files messing
up the build process, and even having some procedures defined multiple
times in different source files.
As for !Path, I used to set that when I first used PV-Wave several
years ago, but having just come back (to IDL), I've found that it has
an IDE, and have been just running that 'out of the box'.
Regards,
Craig
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| Re: Locating IDL source code file [message #44491 is a reply to message #44420] |
Tue, 14 June 2005 16:30 |
Mark Hadfield
Messages: 783
Registered: May 1995
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Senior Member |
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R.G. Stockwell wrote:
> Mark Hadfield wrote in message
>> My second piece of advice: give each routine its own source file.
>
> Again I agree. If you think of what one is doing when they have
> multiple routines in a file, it is an attempt at hiding code from other
> modules. What you really want to be doing is object programming,
> and making methods/routines (i.e. Tom) that are hidden from everything
> except
> the Fred class.
I don't agree with that. Hiding routines from those who don't need to
know about them should not have to be synonymous with
object-orientation. It's just that in IDL classes do have a mechanism
for this hiding and routines don't. Look at Python's modules to see how
this should be done.
(I recommend that any IDL programmer who is interesting in language
design should look at Python and Numeric Python. But be aware in doing
so that some of the choices made in Python have made it *way* slower
than IDL in some situations.)
Back to IDL now. If we have a routine "fred" and we want it to call
another routine that has no other reason to exist, then the conventional
way of achieving this is to give it a name that reflects its relation to
fred *and* its function, then put it in fred.pro *before* the main routine:
*** file fred.pro ***
function fred_add, x, y
return, x+y
end
pro fred
if fred_add(1, 1) ne 2 then message, 'Huh?'
end
*** end file fred.pro ***
This is a kludge, because it's not really private. If file bill.pro
defines a function fred__add then the clash will break things (and will
be very hard to find, to boot). But as long as all the private routines
in bill.pro start with "bill_", there shouldn't be a problem.
Yes, you could avoid this by rewriting fred as a class, but I think in
most cases this would be a perversion of object-oriented programming.
You're still left with the problem that there might be two "fred"s on
the path. This is a problem with IDL's flat name space for routines.
Again, something like Python modules would alleviate the problem, but it
ain't gonna happen any time soon.
--
Mark Hadfield "Kei puwaha te tai nei, Hoea tahi tatou"
m.hadfield@niwa.co.nz
National Institute for Water and Atmospheric Research (NIWA)
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| Re: Locating IDL source code file [message #44494 is a reply to message #44420] |
Tue, 14 June 2005 16:02 |
R.G. Stockwell
Messages: 363
Registered: July 1999
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Senior Member |
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"Mark Hadfield" <m.hadfield@niwa.co.nz> wrote in message
news:d8nko8$1cs$1@newsreader.mailgate.org...
> Hi Craig
...
> ...How does using IDLDE relate to whether the file containing the routine
> is on the !PATH.
>
> My advice: put files containing IDL routines on !PATH.
I agree with Mark. To answer the question, one can open routines
in the IDLDE fairly easily, and compile them because they are in the
DE. When people send me code, I don't put it in my path, and usually
run it in the IDLDE from another folder.
>> Once this problem is solved, I'll also need to determine the filename
>> for the source file containing a definition of 'fred', because most of
>> the routines in this project don't have their own 'fred.pro' source
>> file.
>
> My second piece of advice: give each routine its own source file.
Again I agree. If you think of what one is doing when they have
multiple routines in a file, it is an attempt at hiding code from other
modules. What you really want to be doing is object programming,
and making methods/routines (i.e. Tom) that are hidden from everything
except
the Fred class.
Cheers,
bob
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| Re: Locating IDL source code file [message #44497 is a reply to message #44420] |
Tue, 14 June 2005 15:12 |
Mark Hadfield
Messages: 783
Registered: May 1995
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Senior Member |
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Hi Craig
I know your question has been answered elsewhere, but I'd just like to
make a couple of comments on the original post.
> ...This might be because I'm using
> the IDLDE, so the routine isn't actually on the search path !PATH, even
> though it has been compiled OK when building the project.
This is a bit of a non-sequitur. How does using IDLDE relate to whether
the file containing the routine is on the !PATH.
My advice: put files containing IDL routines on !PATH.
> Once this problem is solved, I'll also need to determine the filename
> for the source file containing a definition of 'fred', because most of
> the routines in this project don't have their own 'fred.pro' source
> file.
My second piece of advice: give each routine its own source file.
--
Mark Hadfield "Kei puwaha te tai nei, Hoea tahi tatou"
m.hadfield@niwa.co.nz
National Institute for Water and Atmospheric Research (NIWA)
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