lisp polyline

Dear ymg3,

you are right - the thing which I need it actually an catenary. In my case, I mentioned parabola as for not quite big spans this does not make much of a difference.

Can you please tell me the units you have specified into your input data?

Do you have the tension in kN or MPa? I guess that is in MPa as you do not ask for the cross section of the conductor.

The weight per unit length - is it in kg/m, N/m or N/m*mm^2?

The eq for y values which I would like to be using is: Y=(specificload*x^2) / (8 * Sigma).

The specific load is in N/m*mm^2 and Sigma is in MPa.

Tomorrow morning I will go deep into the script and check this by myself.

safeda,

Unit should not matter as long as your tension and unit weight

utilizes the same.

For your proposed formula, I am not too sure you can change

units as easily.

Take a look at page 47 of the following pdf

http://okonite.com/okonite-wire-and-cable-product-brochures/Engineering-Handbook.pdf

ymg

ymg3,

can you please help me modify the lisp so that it can work with differenet X and Y scales. The OHTL lines are often in different scales for x and y. For example for lenght 5000 and for hight 500.

I cannot get where I have to integrate the scale ration into the lisp.

safeda,

All you need to do is to multiply your Y by 10

while keeping the x at 1:1

(setq pl (cons (list x (* 10  (+ (* c (- (cosh (/ (- x xv) c)) 1)) yv))) pl)

Can't help you more than this as I am traveling.

ymg