X, Y Filtering

DRAW Reference Manual

Point and Line Construction : X, Y Filtering

A 2D position may be defined in terms of the X or Y coordinates of other points. For example, rather than an explicit point definition such as:

a constructed point could be defined by:

AT X200 Y OF point

The above command would define a position whose Y coordinate would be the Y coordinate of point, where point could include:

•

The endpoint of a line or an arc

•

The centre of a circle or an arc

•

A tangency point

•

An intersection points

•

The point on a line or an arc nearest to a given point

•

The point defined by the perpendicular from a given point

The constructed point could also be defined explicitly or by a cursor hit. For example:

Set the Y coordinate to the Y coordinate of the cursor hit

AT X OF @ Y OF @

X coordinate from first cursor hit, Y coordinate from second cursor hit

The process of deriving a coordinate from a coordinate of another point is known as X, Y filtering. X and Y filters may be used in any command that requires a 2D position on a Sheet, including edits on various Dimension attributes. For example:

PTOF X OF /VALV1 Y @
DTOF X @ Y250
PLCL X @ Y OF POS E3000 S2000 U0

Y coordinate set to the Y coordinate of 2D projection of given 3D position.

3D positions may also be constructed, but this only applies to 2D drafting primitives that are members of VNOT elements. X, Y filtering can be used with any 2D element which has a position attribute, e.g. VIEWs, Labels, Dimension Points etc.

1.

NEW STRA
FPT X100 Y100
TPT X OF @ Y OF @

(or NEW STRA DEF X100 Y100 X OF @ Y OF @)

Here a straight line is created with one of its endpoints defined explicitly and the other constructed using cursor hits. Refer to Figure 19:1.: X, Y Filtering - General 2D Position for further information.

Figure 19:1.

X, Y Filtering - General 2D Position

Here, the ‘to’ point of the line takes its X coordinate from the X coordinate of hit 1 (at 200, 300) and its Y coordinate from the Y coordinate of hit 2 (at 500, 400). The ‘to’ point is therefore (200, 400).

2.

With a cursor hit at (400, 900), the above command would move a Dimension text origin to (400, 250).

3.

PLCL X @ Y OF POS E3000 S2000 U0

Here, a projection line clearance X coordinate would be set to the X coordinate of the cursor hit, the Y coordinate being set to the Y coordinate of the 2D projection of the given 3D position.

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