Coordinate Transformation (GM)
Purpose: To translate or rotate a structure with respect
to the coordinate system or to generate new structures translated
or rotated from the original.
Card:
__________________________________________________________
/2| 5| 10| 20| 30| 40| 50| 60| 70| 80|
/ | | | | | | | | | |
| | | | | | | | | | |
|GM |I1 | I2 | F1 | F2 | F3 | F4 | F5 | F6 | F7 |
| | | | | | | | | | |
| | I | M | ROX | ROY | ROZ | XS | XY | XZ | ITS |
| | T | R | | | | | | | |
| | G | P | | | | | | | |
| | G | T | | | | | | | |
| | | | | | | | | | |
| | | | | | | | | | |
| | | | | | | | | | |
|The numbers along the top refer to the last column in each field
| | | | | | | | | | |
- Parameters:
- Integers
- ITSI (I1) - Tag number increment.
- NRPT (I2) - The number of new Structures to be generated
- Decimal Numbers
- ROX (F1) - Angle in degrees through which the structure is rotated about
the X-axis. A positive angle causes a right-hand rotation.
- ROY (F2) - Angle of rotation about Y-axis.
- ROZ (F3) - Angle of rotation about
- XS (F4) - X, Y. Z components of vector by which
- YS (F5) - structure ir translated with respect to
- ZS (F6) - the coordinate system.
- ITS (F7) - This number is input as a decimal number but is rounded
to an integer before use. Tag numbers are searched sequentially
until a segment having a tag of this segment through the end of
the sequence of segments is moved by the card. If ITS is blank
(usual Case) or zero the entire structure is moved.
Notes:
- If NRPT is zero, the structure Is moved by the specified rotation
and translation leaving nothing in the originallocation.
If NRPT is greater than zero, the original structure remains fixed
and NRPT new structures are formed, each shifted from the previous
one by the requested transformation.
- The tag increment, ITGI, is used when new structures are generated
(NRPTgreater than zero) to avoid duplication of
tag numbers. Tag numbers of the segments in each new copy of the
structure are incremented by ITGI from the tags on the previous
copy or original. Tags of segments which are generated from segments
having no tags (tag equal to zero) are not incremented. Generally,
ITGI will be greater than or equal to the largest tag number used
on the original structure to avoid duplication of tags. For example,
if tag numbers 1 through 100 have been used before a (GM) card
is read having NRPT equal to 2, then ITGI equal to 100 will cause
the first copy of the structure to have tags from 101 to 200 and
the second copy from 201 to 300. If NRPT is zero, the tags on
the original structure will be incremented.
- The result of a transformation depends on the order in which
the rotations and translation are applied. The order used is first
rotation about X-axis, then rotation about the Y-axls, then rotation
about the Z-axis and, finally, translation by (XS, YS, ZS). All
operations refer to the fixed coordinate system axes. If a different
order is desired, separate GM cards may be used.
This file was last modified on