I'm struggling a bit to understand the results of the following program.

Apparently variables are not being changed after the first run. Otherwise I can't explain the results of the last line.

GeometrySegment.mw

Any idea how I catch that error?

(in geometry:-DefinedAs) wrong type of argument |C:/Users/andreas/AppData/Local/Temp/com.maplesoft/NODELibrary-0dc05fe4-0ffc9cfc/lib/NODEFunctions-13751:1976|

Here's the code:

    try
        a := map(coordinates, DefinedAs(segm))[1];
        b := map(coordinates, DefinedAs(segm))[2];
    catch "wrong type of arguments":
        Alert(cat("Error, (in geometry:-DefinedAs) wrong type of arguments, variable segm: ", whattype(segm), segm), table(), 5)
    end try;

I am trying to put an annotation  (dimension of a distance) into a plot.

Any hints about what would the best way to do that?

Apparently functions working on lines do not work on segments.

I can't see any logical explanation why that should be so.

Please consider expanding functionality in future Maple versions.

segprojection.mw

Why is a change in the text area component triggering an action three times in a row?

Download ThePostmanKnocksThreeTimes.mw