Math with XYZWPR variables in Karel?

    Hey guys, I am having some trouble doing math with XYZWPR variables.

    I have two XYZWPR variables, say pos1 and pos2.

    At first I tried to subtract them and get the result into a 3rd XYZWPR variable like so:

    Code
    VAR
pos1, pos2, pos3: XYZWPR

BEGIN
pos3 = pos2 - pos1
END

    But I got an error saying:

    Operator expected POSITION data type for left operand.


    Any idea how to properly do math with that datatype?

    Quote from hermann
    Code
    VAR
pos1, pos2,pos3 : XYZWPR 
pos4: POSITION

BEGIN
 pos4 = pos2 : INV(pos1)
 pos3 = pos4

END

    The robot in most times does automatic conversions between XYZWPR and POSITION.

    Hi,

    Is it possible to access fields of POSITION data just like XYZWPR?

    I have initialized

    uframe, utool : POSITION

    and gett the following error.


    What is the correct syntax to access fields of this position variable? This works for an XYZWPR

    Quote from mahboobelahi93

    Hi,

    Just to confirm,

    Does the orient field contain the roll, pitch, and yaw values? and Location field just contains XYZ values?

    No. This is a matrix representation of the point. The location vector just contains XYZ values, but if you're looking for WPR representation you'll need to convert your position into XYZWPREXT. I believe that karel automatically converts between the data types, so you should be able to declare a new variable as XYZWPREXT and then assign it your position value. Something like this:


    uframe : position

    uframe2 : XYZWPREXT

    .

    .

    .

    .

    uframe2 = uframe

    write(uframe2.x,cr)


    I haven't tested this but from what I've read it should work.

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