How do I get a line's Angle?

You can find the angle using 'axis_angle' measurement.

(axis_angle object1 object2) => Measures the smallest angle (in degrees) between the objects.

There are a couple of different measurements for working with angles, depending on which angle you are looking for. The angle measurement returns the counter-clockwise angle between two linear objects in the range [0, 360]. The principal_value measurement can be used to normalize this angle to the range [-180, 180]. There is also axis_angle, which treats two linear objects as directionless axes and returns the smallest angle between them, which is going to be in the range [0, 90].

I was not familiar with this "normalized" segment angle displayed in the Show Element window, but it seems to be the counter-clockwise angle within the quadrant from x or y coordinate axis to the segment. This angle will be the same regardless of segment direction, it will just shift the quadrant. If we have the angle from a unit vector [1, 0] to the segment, the normalized angle na can be expressed as a mod 90, or the reminder after dividing a with 90. Like in many programming languages, mod only works on integer numbers in Ravel, so we will have to express this a bit more convoluted as na = a - 90(floor(a/90)).

Suppose that you have a relation mysegment with the segments that you want to check. You could then find this angle by:

(define mysegment_angle
  (transform (s) mysegment
    (s (angle (CREATE_VECTOR 1 0) s))))

(define mysgement_normalized
  (transform (s a) mysegment_angle
    (s a - 90.0*(floor a/90.0))))

You would then subtract this from your constraint value and compare the absolute value with some epsilon.

Thanks for the help.  What is this (CREATE_VECTOR) function above?  I thought maybe it was built-in until I got:

    E- *Error* No such derivation or measurement create_vector

Can you "draw" a new line with some make line or vector function?
     (makeLine (start_point myLine),  (point  (xcoordinate myLine + 100), (ycoordinate myLine)) )

So the same starting point as the trace line but add 100 to the X (and the same Y of course so it is horizontal) and then use the angle function with those 2 lines?

My email is rchipman @ micron .com if you need the .SIP file or just want to get in touch. Thanks, Rian

Hello

CREATE_VECTOR is in the Ravel Standard Library.

Purpose: Create a vector from the origin to the given coordinates. Syntax (CREATE_VECTOR x/number y/number) => vector/vector

If you don't have RSLYou can add this before your code.

(macro CREATE_VECTOR (X Y)
"CREATE_VECTOR x/number y/number => vector/vector

Create a vector from the origin to the given coordinates."
(connecting_line (create_point 0.0 0.0) (create_point X Y)))

Thanks,

Kirti

Thanks. Turned out just the angle function and that "normalized" principal_value function did the trick (which is good because I never could get that CREATE_VECTOR to work). Here's the complete code:

(constraint MIN_ANGLE 29.9)
(constraint MAX_ANGLE 30.1)

(define PlatingTrace
  (select (mLine) line
    (and
      (layer? mLine, "SUBSTRATE GEOMETRY/UNITBOT_PLTG_RT") ; RT = Routed
      (length mLine) < 10000.0 ; Exclude main vertical line segment
     )
   )
)

; Go 1000 out on the X axis but same Y axis so it is horizontal
; Yes end_point is the end of the line next to the middle vertical line

(define BadAngles
  (select (mLine, mAngle)
    (transform (mLine) PlatingTrace
      (mLine, (abs (principal_value (angle mLine, (connecting_line (end_point mLine), (create_point 1000.0           (ycoordinate (end_point mLine))))))))
     )
     (or ; angle must be between 29.9 and 30.1 so errors are outside this range < 29.9 OR > 30.1
      (mAngle < (value MIN_ANGLE))
      (mAngle > (value MAX_ANGLE))
     )
   )
)