Type problem

[Cookie Monster]

Hello,

I was wondering whether there is anyone who can help me to override this
error message.

>(check n1 200)

Error: NIL is not of type (OR RATIONAL FLOAT).
Error signalled by <.

(defun check (qnode num_of_sweeps)
(let ((counter 0))
(do ((i 0 (+ i 1)))
((mapc #' (lambda (n)
(cond
((null (node-clamped (eval n)))
(let ((p (node-clamped (eval n)))
(q (prob (eval n))))
(cond ((< p q) (setf (node-tvalue (eval n)) t))
(t (setf (node-tvalue (eval n)) nil)))))))
*node_list*))
(cond ((equal t (node-tvalue qnode)) (+ counter 1)))
((equal i num_of_sweeps) (/ counter i)))))

And here's are the declarations for:

(set *node_list* '(n1 n2 n3 n4 n5 n6 n7))

;; Data Structure for node
(defstruct node tvalue matrix causes effects clamped)

;; Setting each node up with associated values
(setq n1 (make-node :tvalue t
:matrix '()
:causes '()
:effects '(n3 n4)
:clamped t))

.
.
.
etc

Thank you very much.

I would be much appreciated if you could email to me.

Thank you very much,
Doreen

[Lyman S. Taylor]

In article <365850D2...@hotmail.com>,

Cookie Monster <lo...@cs.man.ac.uk> wrote:
>Hello,
>
>I was wondering whether there is anyone who can help me to override this
>error message.
>
>>(check n1 200)
>
>Error: NIL is not of type (OR RATIONAL FLOAT).
>Error signalled by <.

> (cond
> ((null (node-clamped (eval n)))

only take this condition when (node...) is NIL.

> (let ((p (node-clamped (eval n)))

bind NIL (i.e., (node...) ) to p.

> (cond ((< p q) (setf (node-tvalue (eval n)) t))

(< NIL q ) which fails.

Perhaps you only want to take this condition when (node...) is
not NIL. Or bind P to some number.

>
>(set *node_list* '(n1 n2 n3 n4 n5 n6 n7))
>

I imagined this is

(setq *node_list* '(n1 n2 ..... ))

Note you probably should consider

(setq *node_list* (list n1 n2 n3 .... ) )

And then chuck all of those calls to EVAL; just simply use N.

Unless you need the globals variables n1, n2, etc. elsewhere.

--

Lyman S. Taylor "Computers are too reliable to replace
(ly...@cc.gatech.edu) humans effectively."
Commander Nathan Spring, "Starcops"

[Marco Antoniotti]

Cookie Monster <lo...@cs.man.ac.uk> writes:

> Hello,
>
> I was wondering whether there is anyone who can help me to override this
> error message.
>
> >(check n1 200)
>
> Error: NIL is not of type (OR RATIONAL FLOAT).
> Error signalled by <.
>
>

> (defun check (qnode num_of_sweeps)
> (let ((counter 0))
> (do ((i 0 (+ i 1)))
> ((mapc #' (lambda (n)

> (cond
> ((null (node-clamped (eval n)))

> (let ((p (node-clamped (eval n)))

> (q (prob (eval n))))

> (cond ((< p q) (setf (node-tvalue (eval n)) t))

> (t (setf (node-tvalue (eval n)) nil)))))))
> *node_list*))
> (cond ((equal t (node-tvalue qnode)) (+ counter 1)))
> ((equal i num_of_sweeps) (/ counter i)))))

From the code below, it seems that 'node-clamped' returns either 't'
or 'nil'. That is your main problem. The second problem is the use of
'eval'. First, I'd substitute them with '(symbol-value n)', next I'd
look for a different solution based on a separate repository for nodes.

>
>
> And here's are the declarations for:
>

> (set *node_list* '(n1 n2 n3 n4 n5 n6 n7))
>

> ;; Data Structure for node
> (defstruct node tvalue matrix causes effects clamped)
>
> ;; Setting each node up with associated values
> (setq n1 (make-node :tvalue t
> :matrix '()
> :causes '()
> :effects '(n3 n4)

> :clamped t)) <=== This seems to be a generalized
boolean.
>

Cheers

--
Marco Antoniotti ===========================================
PARADES, Via San Pantaleo 66, I-00186 Rome, ITALY
tel. +39 - (0)6 - 68 10 03 17, fax. +39 - (0)6 - 68 80 79 26
http://www.parades.rm.cnr.it