1/ The extention for a vector is .IJK ; .I gives the first component, .J the second and .K the third.
2/ The length of a vector is 1 (1 mm in mm, 1 " in inches). It means that the sum of the squares of the components is 1.
3/ When you use "ANGLEBETWEEN", angle is calculated in degrees between 2 vectors.
Ex : ASSIGN/V1=ANGLEBETWEEN(PL1.IJK,LN1.IJK)
If PL1 and LN1 vectors are <0,0,1>,Anglebetween gives 0° (angle between vectors, not features !), but angle between the plane and the line is 90° !!!
4/ You can create vectors from hits.
Ex : ASSIGN/V1=PT2.XYZ-PT1.XYZ ; It gives the components of the vector PT1PT2 ; Its length is the 3D distance between PT1 and PT2 (ASSIGN/V2=DIST3D({PT1},{PT2}) or ASSIGn/V2=SQRT(DOT(PT2.XYZ-PT1.XYZ,PT2.XYZ-PT1.XYZ)), or ASSIGN/V2=SQRT(DOT(V1,V1))
5/ If you want a classical vector (length =1) along a line between PT1 and PT2, you don't need to create the line, you can use ASSIGN/V3=UNIT(PT2.XYZ-PT1.XYZ) or ASSIGN/V3=UNIT(V1).
6/ Alignment vectors ares calculated in the current alignment, with their name (ASSIGN/V4=AL1.ZAXIS in AL1 gives <0,0,1>, in AL2, it gives the rotation of Z axis between Al2 and Al1)
7/ Cross function (in PC-DMIS, not in the real life !!!) gives a unit vector, perp to the first and the second. ASSIGN/V5=CROSS(LN1.IJK,LN2.IJK) gives a vector perp to both lines. If you need to calculate the distance between 2 cylinders (non coplanar), then you can ASSIGN/V6=DOT(CYL1.XYZ-CYL2.XYZ,CROSS(CYL1.IJK,CYL2.IJK)), which gives directly the good result without any local alignment.
8/ Another way to create a vector, you can use MPOINT function : ASSIGN/V1=MPOINT(10,20,30) construct a point with coordinates <10,20,30> or a vector with the same components. Just to remember that coordinates of a point have the same values than components of a vector from origin to the point, so MPOINT can give a vector !!!
That's all for a monday morning, it's coffee time !
