iPOGO V5 Users Group - Help Manual

*Methodology Number 1 of 2*
Command:	-4
Alpha Alias:	-Arc Dir
Description:	Computes the point of intersection of a line with two or more concentric arcs
Data Format:	-4 Set From Bearing RadiusPoint Near Radius {[Radius] ... } ;
Problem:	Given point number 19 on a line bearing North 65°20’14" East; point number 20 (a point number near the required solution); and point number 21 as the radius point of a curve having a radius of 200 feet. Set point number 22 at the intersection of the line and arc.
Solution:	-4 22 19 -1 65 20 14 21 20 200 ;

Data Description

Command	-4	Computes the point of intersection of two or more concentric curves with the same straight line. The defined line or bearing may intersect the curve at two points. You must indicate your required point of intersection by specifying a point number that is located nearest to the solution to be retained.
Set	22	Point number of the initial point to be computed.
From	19	Point number of a previously computed or stored point which defines the line on which the computed point is to be set.
Bearing	-1 65 20 14	Direction of the line on which the point is to be computed. Bearings may be entered using quadrant definition and angle or point definition.
RadiusPoint	21	Point number of the previously computed radius point of the curve.
Near	20	Point number that is located nearer to the required solution than to the alternate solution.
Radius	200	Radius length of the curve.
{[Radius] ... }		Repeating feature of this command. See Methodology 2 for more information.
End Command	;	All commands end with a semi-colon.

Methodology Number 2 of 2

Command: -4

Alpha Alias: -Arc Dir

Description: Computes the point of intersection of a line with two or more concentric arcs

Data Format: -4 Set From Bearing RadiusPoint Near Radius {[Radius] ... } ;

Problem: Given point number 19 on a line bearing North 65°20’14" East; point number 20 (a point number near the required solution); and point number 21 as the common radius point of curves having radius lengths of 200, 225 and 175 feet. Set point numbers 22, 23 and 24 at the intersection of the line and arcs as shown.

Solution:
-4 22 19 -1 65 20 14 21 20 200 225 175 ;

Data Description

Command	-4	Computes the point of intersection of two or more concentric curves with the same straight line. The defined line or bearing may intersect the curve at two points. You must indicate your required point of intersection by specifying a point number that is located nearest to the solution to be retained. Note:If you use the repeating feature of this command to compute the points of intersection with more than one arc, be sure to enter a Near point that will define all the required solutions.
Set	22	Point number of the initial point to be computed.
From	19	Point number of a previously computed or stored point which defines the line on which the computed point is to be set.
Bearing	-1 65 20 14	Direction of the line on which the point is to be computed. Bearings may be entered using quadrant definition and angle or point definition.
RadiusPoint	21	Point number of the previously computed radius point of the curve.
Near	20	Point number that is located nearer to the required solution than to the alternate solution. Note:If you use the repeating feature of this command to compute the points of intersection with more than one arc, be sure to enter a Near point that will define all the required solutions.
Radius	200	Radius length of the curve or arc.
{[Radius] ... }	225 175	Repeating feature of this command. It allows you to set additional points on the same line by defining new radii from the specified curve center. These concentric curves will intersect with the line and their points of intersection will be tabulated after the original radius length. Additional computed points will be numbered automatically from the Set point number.
End Command	;	All commands end with a semi-colon.

Example Command File

$ Example data set for -4 (-ARC DIR) command,
$   methodology 2

$ Set initial points.
  0 
    21 1000 1000 ;
  1 1000 21 -1 65 0 0 200 ;
  1 1001 21 -4 65 0 0 200 ;
  0 
    19 1123.2  922.6 
    20 1208.4 1192.6 ;

$ Set points using the -4 command
  -4 22 19 -1 65 20 14 
              21 20 200 
                    225 
                    175 ;

$ Set additional points for plotting
  1 1002 22 19 22 100 ;
  1 1003 19 22 19 200 ;

$ Set points using the -4 command
  -4 25 19 19 1003 
           21 1003 200 ;

$ Set additional points for plotting
 -1 1004 21 21 1000 175 
            21 1000 225 ;
 -2 1006 21 21 1000 
                    -50 0 0 175 
                    -60 0 0 225 ;

$ Setup plotting parameters with 
$   feature, layer, color, style, thickness
  15.1 L1 LINES1 7 1 1;

$ Turn plot on
  91;

$ Activate the current feature
  15 L1 ;
          $ Draw the lines.
            7 1 1001 21.1 1000 ;
            7 1 1003 1002      ;
            7 1 1006 21.1 1004 ;
            7 1 1007 21.1 1005 ;

Help for this command was last updated: 06/28/2000 12:08:45 AM

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Group:Command:

4) Brg-Dist Intx-4 or -Arc Dir

Group:
Command:

4) Brg-Dist Intx
-4 or -Arc Dir