stfpr2/stipr2/stspr2

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DCL:GRPH1:STPACK: Transformation Functions:Explanation of Subroutines: Coordinate Transformation

6.3.2 stfpr2/stipr2/stspr2

1.

Function

Performs a 2-D perspective transformation.

2.

Call

rx, ry = NumRu::DCL.stfpr2(x,y)
x, y = NumRu::DCL.stipr2(rx,ry)
NumRu::DCL.stspr2(ix,iy,sect)

3.

Explanation of Arguments

vx,vy (R) The coordinates in VC.

rx,ry (R) The coordinates in RC.

ix,iy (I) Specifies by number which axes in the 3-D space will correspond to the X- and Y-axes in 2-D. (1: X axis; 2: Y axis; 3: Z axis) When a negative value is specified, the axes are inversed.

sect (R) The coordinates for the point of intersection of the axis and the 2-D plane.

4.

Notes

(a)
The parameters for perspective transformation are common with 3-D perspective transformation.

`vx,vy`	`(R)`	The coordinates in VC.
`rx,ry`	`(R)`	The coordinates in RC.
`ix,iy`	`(I)`	Specifies by number which axes in the 3-D space will correspond to the X- and Y-axes in 2-D. (1: X axis; 2: Y axis; 3: Z axis) When a negative value is specified, the axes are inversed.
`sect`	`(R)`	The coordinates for the point of intersection of the axis and the 2-D plane.