=============
nc_line_exp()
=============


.. admonition:: Command: nc_line_exp(x1, y1, x2, y2, nodes, delta, mode)

  Create a node-chain with variable node-spacing.

  **Parameter**
    | :red:`x1,y1` Start-node coordinates
    | :red:`x2,y2` End-node coordinates
    | :red:`nodes` No. of nodes
    | :red:`delta` Position of the node-spacing-change (*0 < delta < 1*)
    | :red:`mode`  Mode of the node-spacing-change (possible values: *'begin', 'end', 'both'*)

  **Examples:**
    Line between points p1=(x1,y1) and p2=(x2,y2) with 9 nodes.

  .. sourcecode:: lua

    nodes = 9
    delta = a/(a+b)   -- in the image below, delta would be 0.25
    nc_line_exp(x1,y1, x2,y2, nodes, delta, 'begin')

  .. figure:: nc_line_exp.png

  which is the same, as using the following code:

  .. sourcecode:: lua

    xm = x1 + (x2-x1)*delta
    ym = y1 + (y2-y1)*delta
    nc_line(x1,y1, xm,ym, math.floor(nodes/2))    -- draws line 'a'
    nc_line(xm,ym, x2,y2, math.ceil(nodes/2))     -- draws line 'b'

  Using ``mode = 'end'`` will automatically set ``delta = 1-delta`` interally.

  ``mode = 'both'`` will split the line into three parts, instead of two.