How can I test if an object exists?

[Thommo]

How can I test if an object exists in my workfile?

[EViews Gareth]

You can use the @isobject command to do this:

Code: Select all

if @isobject("my_ser") then
   delete my_ser
endif


[Victoria]

Hi,
I have tried using the @isobject in my program to make it skip non-existing series, however I am having trouble making it work. When running the statement on a series that doesn't exist:

Code: Select all

!test = @isobject(NO2_OB_SP_BOR_NA)

Eviews returns the error: ` NO2_OB_SP_BOR_NA is not defined in "!TEST =@ISOBJECT(NO2_OB_SP_BOR_NA)" ´. I thought it should have returned !test=0.

All help is greatly appreciated.

[startz]

Pu the object name in quotes.

[Victoria]

Many thanks for your help and swift reply. Quotes worked for the single statement. I am still having troubles however, with using the command for controlling my loops. I think the problem arises when i try to substitute parts of the string in the loops. The code below searches for the object no1_kk_sp_bof_na which does exist in the workfile, !testing returns one, but !testingtwo and !testingthree returns zero. Is there an other syntax typo causing this or am I trying to do something that can't be done?

rgds
Victoria

Code: Select all

'--This works
   pageselect n
   !testing = @isobject("no1_kk_sp_bof_na")
   pageselect Untitled
   scalar testing = !testing
'--But this does not
   pageselect n
   %bof = "bof"
   !testingtwo = @isobject("no1_kk_sp_{%bof}_na")  ' <-----
   pageselect Untitled
   scalar testingtwo = !testingtwo
'--Nor this
   pageselect n
   %obj = "no1_kk_sp_{%bof}_na"
   !testingthree = @isobject({%obj})   'error returned: NO1_KK_SP_{%BOF}_NA is an illegal or reserved name in "!TESTINGTHREE =@ISOBJECT(NO1_KK_SP_{%BOF}_NA)"
   pageselect Untitled
   scalar testingthree = !testingthree
'--How then to use as control inside loops?

[EViews Gareth]

The line:

Code: Select all

 %bof = "bof"
   !testingtwo = @isobject("no1_kk_sp_{%bof}_na")


Is telling EViews to test for the existence of an object literally called no1_kk_sp{%bof}_na, which doesn't exist. Replacement variables will never work when you put them inside quotes.

Add an extra line:

Code: Select all

 %bof = "bof"
 %temp = "no1_kk_sp_" + %bof + "_na"
   !testingtwo = @isobject(%temp)


[bobshackleton]

Hi, I'm having a similar problem but not finding a solution. the following code doesn't create any line graphs, so I think the text inside @isobject is not correct. I have a workfile open and also a database open, and I'm trying to create a line graph only if the series is in the database. Could you explain how to do this correctly?

dbopen {%file_old_cgraw_a} as O_A
pageselect CGRaw_Annual
%all=@wlookup("*","series")
for %i {%all}
%test = "O_A::" + %i
if @isobject(%test) then
line O_A::{%i} {%i}
endif
@uiedit(%stopgo,"OK?")
if %stopgo = "n" then
stop
endif
close @objects
next

[bobshackleton]

I guess I should say that I'm using Eviews 8 Enterprise Edition, 64-bit version.

[EViews Gareth]

You can't use @isobject on a database link. Use @wquery to query the database for the existence of the series instead.

[bobshackleton]

Thanks. I'm having a bit of trouble getting @wquery to work. What am I doing wrong in this code?

%database = %file_old_cgraw_a + ".edb"
%all = @wquery(%database, *, "series")

[bobshackleton]

I guess I should say that I'm getting the following error message:

"%all is not defined or is an illegal command in "%all = @wquery(...)""

The database is correctly named in the error message.

[EViews Gareth]

You probably want something like:

Code: Select all

%all=@wquery("c:\temp\temp.edb", "type=series", "name")


[bobshackleton]

Got it - thanks!