Bengoechea Bartolomé Enrique (SIES 73) wrote:
> Hi,
>
> I've been using RExcel 3.0.1 from VBA a lot lately, using the RInterface
> API. A great tool. I have a number of suggestions and issues. I'm not
> sure whether the right procedure is to post them here, submit them
> directly to Erich, modify the Wiki....
>
> I have source code patches available for all these suggestions except
> the last one.
>
> 1) I find no way to directly determine the excel range modified by
> GetDataframe and GetArray. This range is built from the upper-left cell
> of the argument SheetRange, but the number of rows and cells depends on
> the data, and is not returned to the client code, as far as I've been
> able to determine (but I may be missing something!!). Without this
> information, it's not possible to safely post-process the returned data
> from VBA.
The standard solution is to use use GetArrayToVBA("dim(object)") to
retrieve the size information into VBA from R.
>
> One solution could be to make GetDataframe and GetArray be functions
> instead of subroutines. They could return a reference to the whole range
> where the data is written. This would not break the existing API as VBA
> allows invoking functions without assignment of the return object.
This is not the kind of programming style I want to use. See my earlier
suggestion.
>
> 2) GetDataframe does not have a WithColnames argument like GetArray. I
> find this argument would be very useful, as I often need to transfer
> data frames into Excel without the column names. If it is added as a new
> optional argument with default value True, the current API would not be
> broken.
The idea here is to bring together Excel's data lists and R dataframes.
In Excel, data lists always have to have column names.
If what you transfer is all numeric, as.matrix(dataframe) will allow you
to avoid transferring the column names.
But I still think that if you get a dataframe in Excel, it should and
as a data list, and if you want something different, you can do it, but
you are responsible in your code.
>
> 3) While GetArray properly handles Date objects, GetArrayToVBA and
> GetRExpressionValueToVBA do not, returning numbers instead of VBA Date
> objects. A few changes to RInterfaceSupport.REvalReturn can solve this
> issue and make the functions behave similarly.
The whole transfer mechanism currently is totally rewritten, this
problem will disappear soon.
>
> 4) A minor bug in GetArray: Excel application calculation state is
> stored at the beginning of the procedure in variable oldCalcState.
> Nevertheless, this state is not restored at the end of the procedure as
> I would expect. Instead, automatic recalculation is forced.
>
Fixed. Thanks for spotting this.
> 5) The line at the end of GetArray that pastes the format
> (a.PasteSpecial Paste:=xlPasteFormats) has as side effect unmerging the
> cells in the target range, if they are merged. This is the only issue I
> have no patch for as I'm not completely sure of all the implications of
> this pasting.
>
I do not check for merged cells.
But R does not have a concept of merged cells,
therefore the target range in Excel should not have merged cells.
I do no explicit chech here because I do not think it is worth the effort.
Thanks for the remarks, as you will see in the next release I fixed
things where easily possible already.
>
> Best regards,
>
> Enrique
>
>
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