Software Venture Consulting
ToMarket

FileMaker Pro downloads & Resources
FileMaker Custom Functions
FileMaker Web Viewer Examples
FileMaker Pro & Lasso Consulting
Training
FileMaker Books
FileMaker Articles
FileMaker Error Reference

Free Web Tools
Free FileMaker Tools

Personal Pages
Videos
Adventures
Links

Shopping Cart
Shopping Cart

Search:

Free Newsletter
Signup


Contact


Privacy Policy



FileMaker is a registered trademark of FileMaker, Inc. in the U.S. and other countries.

 FileMaker Pro Custom Functions

List  |  Show Random  |  Upload  |  Add This to Your Site

atan2 ( y ; x )

Rate this function:  

RatingRatingRatingRatingRating
  Average rating: 3.5  (16 votes)
  Discuss this Custom Function

Michael George, Michael George Consulting
mailto:mgeorge@coresupport.com

returns the base angle (arctan) of a triangle with the sides X and Y.

Sample Input:
atan2 ( y ; x )
1 0
1 1
0 1
-1 1
-1 0
-1 -1
0 -1
1 -1
Sample Output:
(in radians)
0
0.7853...
1.5707...
2.3561...
3.1415...
3.9269...
4.7123...
5.4977...


 Then copy & paste into FileMaker Advanced's Edit Custom Function window.

Click here to copy To Clip Manager if you have myFMbutler's Clip Manager installed

Description:

The function atan2(y;x) returns the arctan of y,x with adjustments for the signs of x and y so that the angle returned is the angle of the cartesian point (x,y) in radians.
The commonest use of atan2 is in converting between rectangular and polar co-ordinates. The formula for calculating the *initial* heading for a great-circle route from point A to point B uses atan2.
Please be aware that the parameter order is y,x and not x,y as usual.

Note: these functions are not guaranteed or supported by BrianDunning.com. Please contact the individual developer with any questions or problems.

This is my Custom Function and I want to edit it

Discuss:

The above does not give the same results as Microsoft Excel. I use the following, Note the special for x=0 and y=0, I define ATAN2(x,y) = 0:

Let ( [
a =
Case ( x > 0 ; Atan( y / x ) ;
x < 0 ; If ( y ≥ 0 ; Pi + Atan ( y / x) ; -Pi + Atan ( y / x)) ;
x = 0 ; If ( y > 0 ; Pi / 2 ; If ( y < 0 ; -Pi / 2 ; 0) )) ;
result =a
];
result
)


Convert from 0 to 2*pi: result = mod ( 2* pi + a ; 2 * pi)

Rouel Fernandez, Mountain View, Ca
December 22, 2010 7:20am

Make a comment about this Custom Function (please try to keep it brief & to the point). Anyone can post:

Your Name:
City/Location:
Comment:
characters left. If you paste in more than 1500 characters, it will be truncated. Discuss the function - advertisements and other useless posts will be deleted.
Answer 4 + 1 =
Search for Custom Functions:

Custom Functions Widget
Download the Custom Function Dashboard Widget for OS X
Keep all the latest Custom Functions right at your fingertips!

Newest Custom Functions:

1. phpArrayValue ( array ; key ; pos )
  (Fri, Jan 27, 1:49pm)
2. solfm_timeToMinutes (theTime;roundSec)
  (Fri, Jan 20, 6:26am)
3. filterLines(filterField;filterValue;Result)
  (Sat, Jan 14, 2:20pm)
4. getMaxValue ( theList )
  (Thu, Jan 12, 1:06pm)
5. MiddleWordsIncPunct ( text ; startingWord ; numberOfWords )
  (Sat, Jan 07, 9:16am)
6. WindowInfo
  (Fri, Jan 06, 12:39pm)
7. CenterWindow in Window vert horiz (demension)
  (Fri, Jan 06, 12:25pm)
8. UTF8_to_TXT ( Text , Platform )
  (Wed, Dec 28, 10:44pm)

RSS Feed of Custom Functions