# User:Regina/ODF AngleProblems

Dashboard for collecting, where ODF and LibeOffice differ in regard to angles.

## Angles in ODF

### Datatype Angle

It is in **18.3.1 angle**.

An angle, as defined in §4.1 of [SVG]. An angle is a double value that may be followed immediately by one of the following angle unit identifiers: deg (degrees), grad (gradiants) or rad (radians). If no unit identifier is specified, the value is assumed to be in degrees.

Note: OpenDocument v1.1 did not support angle specifications that contain an angle unit identifier. Angle unit identifiers should be omitted for compatibility with OpenDocument v1.1.

**Problems**

`angle`

is defined as reference to SVG. The default*degrees*is a problem for LibreOffice, because it uses*radians*in most cases. Idea: Introduce a datatype "draw-angle" with default*radians*.- The Note is misleading. Better: If compatibility to OpenDocument v1.1 is desired, then unit identifiers should be omitted.
- Only referencing SVG hides the problem of orientation of angles.
- The attribute 20.77 dr3d:end-angle refers to 18.3.1 for its angle. But in LibreOffice this angle is neither degrees nor radians, but it is 1/10 degree in content, but without unit.
- The attributes draw:start-angle and draw:end-angle (from circle sector) refer to 18.3.1. and they are used in degree without unit.
- draw:transform="rotate(0.523598775598299)" is interpreted as counterclockwise in regard to UI in LibreOffice and as clockwise in regard to UI in Powerpoint. The users sees 30° for rotation in PowerPoint and in LibreOffice as well.

### Trigonometric Functions

In **19.171 draw:formula**

sin(n) returns the trigonometric sine of n, where n is an angle specified in **degrees**

cos(n) returns the trigonometric cosine of n, where n is an angle specified in **degrees**

tan(n) returns the trigonometric tangent of n, where n is an angle specified in degrees

atan(n) returns the arc tangent of n in degrees

atan2(x,y) returns the angle in degrees of the vector (x,y) with the x-axis

LibreOffice uses radians in all cases.