xget and dataframes

[Elderfield.A]

Hi,

Is there any way to pass a dataframe object from R to EViews using XGET. The below works fine

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xget(name=df, type=matrix) "as.matrix(df)"


However, the matrix object does not have any column names (there are 138 columns). Is there any way to pass the names to EViews either with the object (so the column names are preserved) or as a string vector?

Thanks

Adam

[EViews Steve]

EViews supports R data.frames, but perhaps your data.frame is in a format that EViews doesn't recognize?

To get a better understanding of how EViews supports data.frames, try the following simple example:

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wfcreate a 1991 2000
series x = @trend
series y = @nrnd
xopen(r)
xput(rtype=df, name=both) x y
delete x
delete y
xget both

You should end up with the same X & Y series back from R.

Take a close look at the "both" data.frame in R and inspect it's attributes. You'll see that it has "$row.names", "$names", and "$is.series" attributes that help EViews understand what each column is.

2023-07-14_07h55_56.png (5.08 KiB) Viewed 9336 times

Also, when you run the final XGET command above, you'll see that EViews is retrieving each column from the data.frame separately:

2023-07-14_07h54_39.png (3.1 KiB) Viewed 9336 times

So if you're having trouble getting your own data.frame in a single call, try retrieving each column one at a time by using the "data.frame$column" nomenclature, like this:

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xget(name=xx, type=series) both$x

Steve

[Elderfield.A]

Thanks Steve - very detailed and useful answer I appreciate it!

Yep, loading the DF works just fine. Is there a vignette or something that details the x family functions that I can read? The whitepaper seems a little limited.

As a side note, is COM automation on the cards? I'm currently achieving what I need via using R to write an EViews program, which I can run via the shell. It would be awesome to have COM automation ability available like you do with Excel VBA.

Thanks

Adam

[EViews Steve]

We provide an online reference for our various commands (including all the X commands), here's the page for XGET. There's also a page that discusses using EViews with R.

EViews has had the ability to be a COM Automation server (like Excel) since EViews 7.

And since we already have our own programming language, you can just use that to program EViews. Here's the whitepaper that discusses how to use the EViews COM Automation interface. It has examples of controlling EViews from VBA and Visual Studio projects.

Steve

[Elderfield.A]

Great - that is really handy!

Thanks for sharing the link to the COM whitepaper. I have to admit, translating this to an R environment (as opposed to VBA) is a little beyond my capabilities. Do you have an example of how this could be achieved?

[startz]

You might want to take a look at https://cran.r-project.org/web/packages/EviewsR/vignettes/EviewsR.html, which may give you a different, but easier, approach.