Coordinates on an Ellipse

Description

By Eddie Shore, January 2016 (Eddie's Math and Calculator Blog)

Store the following values before running:
R0 = number of points. θ always starts at 0° to 360° in equal increments.
R1 = a, length of horizontal semi-axis
R2 = b, length of vertical semi-axis
The centre of the ellipse is at (0,0)

To calculate the coordinates:
f B show first point number
R/S show X coordinate
R/S show Y coordinate
R/S show next point number
etc.

Program Resources

Labels

Name Description
 B Main program, initialise registers
 2 Coordinates calculation

Storage Registers

Name Description
 0 Number of points to be calculated
 1 Length of horizontal semi-axis a
 2 Length of vertical semi-axis b
 3 Counter
 4 Angle increment

Program

Line Display Key Sequence Line Display Key Sequence
000 016 45 3 RCL 3
001 42,21,12 f LBL B 017 43 44 g INT
002 43 7 g DEG 018 31 R/S
003 45 0 RCL 0 019 45,20, 4 RCL × 4
004 1 1 020 36 ENTER
005 30 021 24 COS
006 3 3 022 45,20, 1 RCL × 1
007 13 10ˣ 023 31 R/S
008 10 ÷ 024 34 x↔y
009 44 3 STO 3 025 23 SIN
010 3 3 026 45,20, 2 RCL × 2
011 6 6 027 31 R/S
012 0 0 028 42, 6, 3 f ISG 3
013 45,10, 0 RCL ÷ 0 029 22 2 GTO 2
014 44 4 STO 4 030 43 32 g RTN
015 42,21, 2 f LBL 2