[Texmacs-dev] Re: texmacs... a couple of questions....

[Joris van der Hoeven]

> R has what they call 'expressions'. I attached a file that explains those.

Thanks.

> > OK. So we really need intelligent ways inside TeXmacs to fold large output.
> > We plan to design such things anyway for computer algebra sessions.
> 
> Is it possible to fold now? I could not find it in the manuals.

A very little bit (experimental), but this will be improved.

> > What other interesting objects do you have? Polynomials? ...?
> 
> I think that the main objects are things like summaries of analysis of 
> variance and things like that. Different types of nested objects. 

OK.

> The newest version works pretty well. I had a couple of problems:
> 
> postscript prints/exports really nicely. latex exports figures as "epsf=" but 
> no filename is given. (All graphics are inline with ps:, right?)

Yes the problem is that the graphics are inline; should we generate
a whole bunch of files for them? What filenames to use; I don't know...

> export to html ignores the who session, and only prints things from outside 
> the session.

Export to html is *very* experimental, but it will be improved during
the next months.

> After thinking a bit, I think that it is not so simple to make a better 
> interface with R grpahics than already exists. The problem is that graphs in 
> R can by updated with commands. Thus you can write
> plot(1:100,sin(1:100));points(1:100,cos(1:100))
> which will generate a graph with points for sin and cos. In the X11 interface 
> this is easy to handle: first the plot is drawn, and then the points are 
> added. The problem with the interface to TeXmacs is that at some point the ps 
> file has to be displayed. If it is displayed after every graphics operation, 
> then you'll get two figures, one with only sin(), and the other with sin() 
> and cos(). You could put the postscript file as a link (i.e. not inline), and 
> tell TeXmacs to update what it shows at the end of the command. That is a bit 
> more complicated....
> Currently you have to do this:
> plot(1:100,sin(1:100));points(1:100,cos(1:100));v()
> and you'll get one graph.
> You can do
> plot(1:100,sin(1:100));v();points(1:100,cos(1:100));v()
> to get both graphs..

In fact I see two interesting applications for graphs from R:
using them in a spreadsheet without that the user notices it,
or interactively in a session. I agree that we have to find
a solution to the problem of several operations on the same graph.
Maybe Andrey or someone on the texmacs-dev list has some ideas on that.
I will think about it too.

Yours, Joris