graphical interface to commands?



On 03/19/2010 07:12 AM, Mario Rodriguez wrote:
>> >  I would like to be able to do the following.
>> >     Assume that f(x) is defined.
>> >     1. Generate an empty plot window.
>> >     2. Pick the points in the window with the mouse and generate a line
>> >  segment on the plot.
>> >     3. Perhaps with the use of another key pressed, generate the image of
>> >  the line segment and plot it (just as the commands above do).
>> >  
>> >  Thus, I want a graphic interface to the selection of the line segment
>> >  and the plotting of its image.
>> >  
>> >  Any ideas will be appreciated.
>> >  
>> >  -sen
>>      
>
> Hello,
>
> I don't know if it is possible to send information generated by Gnuplot
> back to Maxima through the pipe. That would be very nice. But it is
> possible to write some information into a file from Gnuplot and then let
> Maxima read it and make something with it.
>
> The script below is an example. First, you middle clic on the window to
> select the points; after every clic, press the 'x' key to save the
> coordinates into file 'data_for_maxima'. Once you have finished your
> selections, press the 'd' key and the polygonal line should be plotted.
>
> Once you press 'd', Gnuplot writes into file 'message_for_maxima.mac'
> the code 'message:1$'. Meanwhile, Maxima is repeating an endless
> while-loop; during every iteration, Maxima reads if variable 'message'
> has changed from 0 to 1. When it is equal to 1, Maxima reads the
> contents of 'data_for_maxima' and plots the segments.
>
> See also embedded comments.
>
>    
Hi Mario,
  Thanks for the code.  It gives me a beginning.

Here is a question about the code.

When I do the plot, instead of seeing the coordinates on the screen, I 
only see the second coordinate.
The shown coordinates look like
   ]1,1.2000 -:00, y]  where y is the second coordinate.
Why is this? Also, how do I correct it so that I see both coordinates?

TIA,
  -sen