L@ Line Curve Connection¶

Use this command to insert lines with special curve paths between two points.

Parameters¶

Parameter	Default Value	Description
Param.1	1	Conn.no. – Connection point number (1–20)
Param.2	0	Conn.typ. – Connection type
Param.3	0.000	Curv.par – Curve parameter. Depends on Conn.typ

Connection Types¶

0 = No line (used for the first point)
1 = Straight line (no parameter needed)
2 = Hanging parabola (used, for example, for power lines)

Curve Parameter for Hanging Parabola¶

For Conn.typ 2 (hanging parabola): Set K = Conn.par/1000 (to allow suitable sizes in GDP). y = Kx² + Mx + N, where M is the slope of the straight line, and N is the starting height.

M and N are determined automatically from the coordinates of the two points to be connected, so only Conn.par needs to be specified.

Tip

Typical value for drawing power lines: Conn.par = 0.4 (or K = 0.0004).

Note

An MO command must be given immediately before the L@ command. This command will then draw a given line path from the previous point with the same Conn.no. up to this one.

Using the Command¶

Info

This command is best used in parametric figures. It is easy to create a parametric figure of a power pole with several connection points (with different numbers). By repeatedly inserting this figure, you can draw power lines with multiple paths.

Examples¶

Simple Parabola Line¶

A simple parabola line can be specified as follows:

MO,0,0,0        - Start coordinate
L@,1,0,0        - Set this to connection point number 1, and no line type
MO,100,0,50     - Next coordinate
L@,1,2,0.4      - New connection point, parabola curve from previous with same number

Parametric Figure with Power Lines¶

The figure FI4101.BIN contains a simple pole, where two cables are drawn between each figure when inserted repeatedly. The figure is in FI0400.LIB and can be inserted via the menu.

This figure contains the following commands:

MO,.000,.000,6.000

$$
  Define leading texts, variables, and default values
VT,.000,.000,.000
  Conn.typCurv.par
VD,10.000,20.000,.000,.000
**,.000,.400

$$
  Draw center pole
MO,.000,.000,.000
P9,.100,.050,4.000,6.200

$$
  Draw crossover, using volume
VS
MO,-.050,-1.600,6.200
R1,.100,3.200,.000
VE,.200,3.000

$$
  Draw hangup point
MO,.000,1.600,6.200
SO,.000,1.500,6.000
SO,.000,1.400,6.200
SO,.000,1.600,6.200

$$
  Define connection point 1, with vertical surface for line
MO,.000,1.500,6.000
VS
VP,.000,10.000,20.000,.000
L@,1.000,1.000,.000,,       ; Use Conn.typ=var.10 Curv.par=var.20
VE,0.030,0.000,,,           ; 3 cm high surface

$$
  Draw hangup point
MO,.000,-1.300,6.200
SO,.000,-1.500,6.000
SO,.000,-1.600,6.200
SO,.000,-1.300,6.200

$$
  Define connection point 1, with vertical surface for line
MO,.000,-1.500,6.000
VS
VP,.000,10.000,20.000,.000
L@,2.000,1.000,.000,,       ; Use Conn.typ=var.10 Curv.par=var.20
VE,0.030,0.000,,,           ; 3 cm high surface

$$
  Back to figure origin
MO,.000,.000,.000,.000

The figure is also available in text form as FI4101.SYM for those who want to make their own changes.

Note

VS and VE commands around L@ commands can be omitted if you do not want surfaces generated along the wire stretches.

General Usage Procedure¶

Fremgangsmåte

GL,4 – To snap poles to terrain
NF,4101
DF
PF – Specify Conn.typ = 0 for the first point (these three commands come automatically if the menu is used)
Place the first figure dynamically
Press [Backspace], and change Conn.typ to 2 (parabola), and set a suitable Curv.par (0.4)
Place more figures dynamically along the stretch