[PD] Calculating Inverse Kinematics Using Expr

[me.grimm]

Hello,

I am trying to calculate inverse kinematics in 2D space with 2 DOF
according to this tutorial(1) and formulas within using [expr]. For some
reason my calculations for "c2" using [expr] deliver quite a different
result than the excel sheet calculation that the tutorial provides.

What am I doing wrong here? It may be I don't quite understand how "^" is
used?

Using:
Linkage 1 length of 5
Linkage 2 length of 4

and plotting my the end of joint 2 at (3.56, 6.43) I should get c2 to equal
0.3254625 but get 0.25 with [expr]. Because of this further calculations to
get joint angles are also off, obviously.

attached is patch.

but maybe someone has already done this type of work which might save me
some trouble...

cheers
m


(1)
http://www.societyofrobots.com/robot_arm_tutorial.shtml#inverse_kinematics

-- 
____________________
m.e.grimm, m.f.a, ed.m.
syracuse u., tc3
megrimm.net
____________________
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20170125/f510c855/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: kin.inv.2d.2dof.pd
Type: application/octet-stream
Size: 1108 bytes
Desc: not available
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20170125/f510c855/attachment.obj>