[draw2d] How to selectively connect an arbitrary number of points

I'm sorry, while writing the email I was playing with draw2d and I have
modifies some values. Of course, if in the draw2d section there is

points([[0,1],[1,2]]),points([[4,4],[5,6]]))

it is

NodeCoord : matrix([0,1],[1,2],[4,4],[5,6]);

and also

"The key is how to automatically generate the line
"points([0,1],[1,2]),points([4,4],[5,6])"...

Stefano



2012/5/22 Stefano Ferri <ferriste at gmail.com>

> I'm trying to plot some 2-d geometric figures, composed by points
> selectively joined by lines. I'd like to write a code able to deal with a
> variable numbers of points and lines (which represent particular
> connections), but I'm having some difficulties.
>
> Points are defined in a matrix with as many rows as the number of points,
> and two columns (two coordinates for each point). In general, it is an
> input of my plot script and it has a variable number of rows.
>
> Here is an example:
>
> NodeCoord : matrix([0,0],[0,1],[2,3],[4,5]);
>
> The i-th point corresponds to the i-th line of this matrix.
>
> I have another matrix, which defines how points are connected. For
> example, point 1 is connected to point 2, 3 to 4. I have called this matrix
> ConnectMatrix.
>
> ConnectMatrix : matrix([1,2],[3,4]);
>
> Each row of ConnectMatrix defines a line connecting the two points in the
> row itself.
>
> An example of the plot routine is the following:
>
> draw2d(  point_type = dot,
>              line_width =2,
>              color         = blue,
>              points_joined = true,
>              points([[0,1],[1,2]]),points([[4,4],[5,6]]));
>
>
> The key is how to automatically generate the line
> "points([0,0],[1,0]),points([3,4],[5,6])", considering that the numbers of
> these elements can be variable. I have to specify a
> points([[node1],[node2]]) separately for each line, because points can be
> defined in a sparse order, and only ConnectMatrix establishes how
> connections are made.
> I have written a routine capable to generate the points([[node1],[node2]])
> for each row of ConnectMatrix, but I'm having troubles with joining them
> and make draw2d work.
> For example, I've tried to create a string "points([[node1],node2]]),
> points([[node1,node2]]" and convert it with flatten, but it remains an
> atomic expression and draw2d complains about it.
>
> Thanks
> Stefano
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