Entity Data Access Symbols Overview | Symbol List
There are several EDAs that access the geometric properties of a spline. READ ONLY EDAs can be accessed to extract the geometric properties only.
Coordinates of point n represent the X, Y, and Z location in the work coordinate system of the nth knot point in the spline. If the number specified is larger than the number of knot points in the spline, the error message ILLEGAL OBJECT displays and 0,0,0 is returned.
|
Geometric Property |
EDA Symbol |
Access Type |
Data Type |
|
Start point (X,Y,Z) |
&SPOINT(obj) |
RO |
Num. Array |
|
End point (X,Y,Z) |
&EPOINT(obj) |
RO |
Num. Array |
|
Number of points |
&NUMSPT(obj) |
RO |
Number |
|
Coord's of point n |
&POINT(obj,n) |
RO |
Num. Array |
|
Tan. vect. at point n |
&TVECT(obj,n) |
RO |
Num. Array |
|
Chord sum at point n |
&PAR(obj,n) |
RO |
Number |
This example demonstrates the use of the spline EDAs to extract the coordinates of the last knot point in any spline.
Declarations
ENTITY/SPL
NUMBER/N(3)
L10:IDENT/'PICK SPLINE',SPL,RESP
JUMP/L10:,TERM:,,,,RESP
K=&NUMSPT(SPL)
N=&POINT(SPL,K)
PRINT/'LOCATION OF POINT'
PRINT/FSTR(N(1))
PRINT/FSTR(N(2))
PRINT/FSTR(N(3))
TERM:HALT
The location of the point would be displayed:
LOCATION OF POINT
6.375
2.250
0.000
By using the number of points EDA, you are assured of always reading the last point and never exceeding the number of points in the spline.