[l-math-devel] thanks for the package and am I doing something wrong?

[Mirko Vukovic]

On Thu, May 20, 2010 at 5:37 PM, Rudy Neeser <rudy.neeser at gmail.com> wrote:
> Hi Mirko,
>
> Thanks for the bug report. This is definitely a bug and not something that
> you're doing wrong. The error doesn't occur in SBCL, which is why I never
> noticed it.

I also have SBCL on another machine, but I like to use CLISP too
(don't know why).  Anyways, this is not the first time that running on
clisp found `errors' in code.  Something like this happened with GSLL
as well.

>
> The patch you've given won't work in all cases: unfortunately when the
> VECTOR and MATRIX classes initialise themselves, they never initialise the
> values in their data arrays. So I've fixed their respective INITIALISE-DATA
> methods to ensure that their data arrays are always initialised.
>
> I've put a fix in the 0.3 series repository, and I'm about to release
> version 0.3.2 with the fix, which should be out later today or on Friday. If
> the new version also gives you problems, let me know.

Can you put out an announcement when the 0.3.2 comes out.  I will
check it out then.

>
> Thank you very much for pointing this out!
>

Hey, thank *you* for the package :-)  Saved me some time and coding.
> Best,
> Rudy
>

Mirko
>
>
> On Thu, 2010-05-20 at 11:06 -0400, Mirko Vukovic wrote:
>
> Hello,
>
> First, thanks for the package.  Second, here is a little problem.  I
> fixed it, but I wonder if I am doing something wrong.
>
> For starters, this is on clisp 2.47 running on cygwin/windows.
>
> I am doing some vector rotations, and I was getting errors such as
> trying to add a number to NIL.
>
> Consider the following:
> (let* ((vec (vector 1.0 0.0 0.0))
> 	   (mat (roll-matrix 3 (/ pi 2))))
>       (* mat vec))
>
> I get the following error:
>
> COMMON-LISP:+: NIL is not a number
>    [Condition of type SIMPLE-TYPE-ERROR]
>
> I traced the error to the matrix being filled with nil's instead of zeros.
>
> I did two modifications in the code, where I tagged the modifications
> as features
>
> In operations.lisp,
>
> (defmethod c* ((lhs matrix) (rhs vector))
>   (test-dimensions lhs rhs)
>   (let ((result
> 	 #-clisp (make-vector (matrix-rows lhs))
> 	 #+clisp (make-vector (matrix-rows lhs)
> 			     :initial-elements
> 			     (make-list (matrix-rows lhs)
> 					:initial-element 0.0))))
>     (do-each-matrix-element (el lhs i j)
>       (setf (elt result i)
> 	    (cl:+ (elt result i)
> 		  (cl:* el (elt rhs j)))))
>     result))
>
> and in matrix.lisp
>
> (defun make-identity (size)
>   "Creates an size x size identity matrix."
>   (let ((matrix
> 	 #-clisp (make-matrix size size)
> 	 #+clisp (make-matrix size size
> 			     :initial-elements
> 			     (make-list (* size size)
> 					:initial-element 0.0))))
>     (dotimes (i size matrix)
>       (setf (matrix-elt matrix i i) 1))))
>
> Thanks,
>
> Mirko
>
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