| Re: IDL_Savefile use [message #79799 is a reply to message #79703] |
Thu, 29 March 2012 08:59  |
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Russell[1]
Messages: 101
Registered: August 2011
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Senior Member |
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On Mar 28, 12:26 pm, desertdryad <dry...@gmail.com> wrote:
> I am trying to use the IDL_Savefile class within a procedure, which
> needs to restore structure variables that I've previously saved to
> file using 'SAVE'. This works fine - to a point. I can restore the
> variable, but I can't figure out how to programmatically reference the
> variable I've just restored!
>
> Here is a bit of code :
>
> sObj = OBJ_NEW('IDL_Savefile', structurefile)
> sinfo = sObj->Contents()
> print, 'struct contents are :', sinfo
> sName = sObj->Names()
> print, 'saved structures name is :', sName
>
> RESTORE, sName, /VERBOSE
>
> .. which all does what I expect, but I afterwards want to reference
> the structure variable that is contained as a strong in 'SName'. How
> I do that? Ie, the below does not work:
>
> tag_idx = WHERE(TAG_NAMES(sName) EQ STRUPCASE(thevariable), count)
>
> because 'sName' is a string containing the name of my structure not
> the variable itself. How can I programmatically get at the variable,
> without passing the name to the procedure? (which to me defeats the
> purpose of Names() altogether) I must be missing something incredibly
> simple... which would be easy, since I'm not terribly good at object
> based programming in IDL.
>
> thanks,
> Cyndy
Hi Cyndy,
I'm not sure what you're asking for exactly, but this is a little
routine that I use extract certain variables from a save file (without
restoring the whole file). Of course, you need to know the name of
the file and the name of the variable (as it is stored in the file),
but you can effectively rename it upon output....
function read_from_save,savefile,variable
if file_search(savefile) ne savefile then begin
message,'File not found',/continue
return,-1
endif
oSave=obj_new('IDL_Savefile',savefile)
variables=oSave->Names()
g=where(strlowcase(variable) eq strlowcase(variables),n)
if n eq 0 then begin
message,'Variable not found in file',/continue
obj_destroy,oSave
return,-1
endif
oSave->Restore,variables(g(0))
obj_destroy,oSave
q=execute('return,'+variable)
if q eq 0 then begin
message,'Something failed, and not sure what?',/continue
return,-1
endif
end
so you call it like:
newvariable = read_from_save(SAVEFILE,VARIABLE)
but variable is a string with the name of the variable (as it appears
in the savefile).
Hope this helps,
Russell
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