one single program that works for differently named objects

[neptunhiker]

Hi everyone,

I am absolutely new to eViews and I am very grateful for your patience with me and your advice.

I have written a program which I want to run on different pages in my workfile, which contains times series that have similar names. Just to clarify what I mean, here is a short example.

Page 1: series TTT_8
Page 2: series TTT_4
Page 3: series TTT_12

So, the pages each contain a series with the Name TTT_ followed by an id, which can have one digit, also 2,3 or more. The programs that I have written look like this:

For Page 1:

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series r=TTT_8/TTT_8(-1)

For Page 2:

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series r=TTT_4/TTT_4(-1)

For Page 3:

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series r=TTT_12/TTT_12(-1)

As you can imagine, there will be more than 3 pages and more than 3 programs to write in the future. So, I would like to write a program, that works for objects with different names. Is there a possibiliy to substitute the id in my times series with something like a star or a question mark? I hope I have made myself clear. Not so easy to explain for a beginner. Anyway, what you see below is what I have in mind for a solution:

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series r=TTT_*/TTT_*(-1)

Or with a question mark:

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series r=TTT_?/TTT_?(-1)

Thank you very much for your help. I really appreciate it.

[EViews Gareth]

Just use a program variable. Reading Chapter 6 of the EViews Command and Programming Reference is probably beneficial.

[neptunhiker]

Thank you for your advice. I read chapter 6 and here is what I can come up with:

For Page 1:

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' Define program variable %id="8" ' Calculate return series series r=TTT_{%id}/TTT_{%id}(-1)

For Page 2:

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' Define program variable %id="4" ' Calculate return series series r=TTT_{%id}/TTT_{%id}(-1)

For Page 3:

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' Define program variable %id="12" ' Calculate return series series r=TTT_{%id}/TTT_{%id}(-1)

So far so good, I guess, but that is not really what I wanted. I would like to avoid defining any id. The program variable that I am looking for is supposed to be some kind of placeholder. Unfortunately I didn't find anything like that in the users guide. I'd be happy, if someone could guide me in the right direction;)

[EViews Gareth]

You could use the @wlookup command to obtain the name of the series in a specific page.

[neptunhiker]

Thank you very much for your advice. It seemed to be the right hint. I have tried using the @wlookup command and here is my solution:

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' Define program variable %id=@wlookup("TTT*","series") ' Calculate return series series r_{%id}={%id}/{%id}(-1)-1

And it does work for the three different pages I have created, nice! BUT, unfortunately I have come up with another problem with the @wlookup command. If I want to estimate an equation using the following program (r_index contains returns that are closely realted to the returns of the TTT series)

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' Define program variable %id=@wlookup("TTT*","series") ' Calculate return series series r_{%id}={%id}/{%id}(-1)-1 ' Estimate equation equation ols_{%id}.ls r_{%id} c r_index

then I will not get any results in the equation output. It states "equation does not have estimates". If I substitute the last line in my code with:

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equation ols_TTT_8.ls r_{%id} c r_index

then everything works out fine and I get results. So, I wonder why does the equation not have any estimates, especially since creating series with for example

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series r_{%id}

works perfectly fine. Why does eViews not create an equation with the name given by the @wlookup command? I am hoping for help, again;) Thanks.

[EViews Gareth]

We'd need to see the workfile

[neptunhiker]

This is the workfile, I am working with.

[EViews Gareth]

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' Define program variable %id=@trim(@wlookup("TTT*","series"))

[neptunhiker]

Hi Gareth,

thank you very much. It works that way. I just don't understand why. Could you tell me the reason? @trim deletes spaces on the left and right, but there are no spaces that need to be deleted, right?

[EViews Gareth]

There was a trailing space.