#### 15.1 Settings for expressions

By right-clicking on an expression and choosing ’settings’ you get a settings dialog for the
expression.

For expressions that were generated with ’enter expression’, you can change the expression you
entered. Be aware of the fact that this might lead to a re-ordering of objects. If you
generate a circular dependency of objects by changing the expression, the change will be
refused.

The setting ’display in HUD’ is now the standard-setting for expressions. HUD means ’heads up
display’, meaning that you always see the expression from above. If you deselect this option, the
expression will rotate with the scene.

This makes sense if you do not want the expressions to rotate with the scene. For those ’fixed’
expressions you will have to check ’Display in HUD’. If you want to be able to move expressions like
points, deactivate this option.

The font-size for expressions can be changed here.

In the ’variable-list’ you can enter a comma-separated list. If those variables are contained in
the expression they will be treated as function-argumets. This way it is possible to define your own
functions.

Example: The determinant of three vectors. This can be computed by (×) ⋅ . If you enter the
expression (a^b)*c in the expression-dialogue and write a,b,c to the variable-list, you have
defined the determinant as a function. Name this expression ’det’ and use it as ’det(a,b,c)’ in other
expressions.