ATAN2 missing?

[cdeaglejr]

The ATAN2 function appears to missing.

a = 0.5

b = -0.765

c = atan2(a, b)

PRINT "c = ", c

END

Start program
No such variable line # 5

[Andries Pretorius]

Agree. I've got Control BASIC v0.79. Gives the same error!

[Andries Pretorius]

ATAN2 was first implemented in the Control BASIC v0.75 firmware.

I therefore tested ATAN2 with the following firmware versions:
Control BASIC v0.75
Control BASIC v0.76
Control BASIC v0.77
Control BASIC v0.78
Control BASIC v0.79
Control BASIC v0.80

I can confirm that ATAN2 ONLY works in the Control BASIC v0.75 firmware and NONE of the subsequent firmware versions up to v0.80.

Maybe Daniel can help here!

Regards

Andries Pretorius

[cdeaglejr]

Here's a four quadrant inverse tangent subroutine named ATAN3. It determines angles between 0 and 2 PI radians.

Code: Select all

' demo_atan3.bas

' June 24, 2015

' demonstrates how to intereact with the ATAN3 subroutine

dtr = PI / 180.0

rtd = 180.0 / PI

angle_deg = 222.25678

' convert angle to radians

angle_rad = dtr * angle_deg

' compute sin and cosine of angle

a = sin(angle_rad)

b = cos(angle_rad)

' call four quadrant inverse tangent

GOSUB ATAN3:

' print results

print " "
print "user-defined angle = ", angle_deg, " degrees"
print " "
print "a = ", a
print "b = ", b
print " "
print "angle from ATAN3   = ", rtd * c, " degrees"

END

ATAN3:

  ' four quadrant inverse tangent function

  ' input

  '  a = sine of angle
  '  b = cosine of angle

  ' output

  '  c = angle (0 =< c <= 2 * pi : radians)

  '''''''''''''''''''''''''''''''''''''''''

  pidiv2 = PI / 2.0

  x = a

  GOSUB SIGN:

  sgn_a = sgn

  x = b

  GOSUB SIGN:

  sgn_b = sgn

  IF (ABS(a) < 1.0e-10) THEN

    c = (1.0 - sgn_b) * pidiv2

    RETURN

  ELSE

    c = (2.0 - sgn_a) * pidiv2

  ENDIF

  IF (ABS(b) < 1.0e-10) THEN

    RETURN

  ELSE

    c = c + sgn_a * sgn_b * (ABS(ATAN(a / b)) - pidiv2)

  ENDIF

RETURN

'''''''''''''''
'''''''''''''''

SIGN:

' sign of a variable subroutine

' input

'  x = argument

' output

'  sgn = sign of x

''''''''''''''''''

IF (x > 0.0) THEN

   sgn = 1.0

ENDIF

IF (abs(x) <= 1.0e-12) THEN

   sgn = 0.0

ENDIF

IF (x < 0.0) THEN
  
   sgn = -1.0

ENDIF

RETURN

Here are the results from the demo;

Start program

user-defined angle = 222.25678 degrees

a = -0.672454395
b = -0.7401385589

angle from ATAN3 = 222.25678 degrees

Program Ended.