topic Re: Please help! Lisp problem in AutoCAD Forum

Please help! Lisp problem

jlee107 — Fri, 22 Dec 2023 06:32:59 GMT

Hello, just to let you all know I only have basic knowledge of coding and I used ChatGpt to create this code. I'm trying to create a Lisp for zwcad(autocad) that could help me to increase my performance at my job. I want a block name to be automatically chosen and placed according to a length of a polyline selected on a model space after command is executed. So after I select a polyline, it should calculate a length of a polyline and find a midpoint. I want base point of a block to be an inserting point of a block and base point should be placed at midpoint of a polyline. For example if a length of a polyline I select is '8000mm', it calls a block name '7100e (8000-900 + suffix 'e')' from the block list and places that block at midpoint of selected polyline. I am certain there are block names ranging from 5400e~12200e (in increment of 100), but it doesn't seem to be able to find a block name appropriate to the length of a polyline. I've been keep getting this error message "Error: Retrieving the ID of the failed name - nil". Please help me it's urgent...

(setq selectedPolyline (car (entsel "\nSelect a polyline: ")))

(if (and selectedPolyline

(member (cdr (assoc 0 (entget selectedPolyline))) '("POLYLINE" "LWPOLYLINE")))

(progn

(setq polylinePoints (mapcar 'cdr (vl-remove-if-not '(lambda (x) (= (car x) 10)) (entget selectedPolyline))))

;; Ensure there are at least two points

(if (< (length polylinePoints) 2)

(princ "\nError: The selected polyline must have at least two points.")

(progn

(setq startPoint (car polylinePoints))

(setq endPoint (cadr polylinePoints))

;; Calculate the midpoint

(setq midpoint

(list (/ (+ (car startPoint) (car endPoint)) 2.0)

(/ (+ (cadr startPoint) (cadr endPoint)) 2.0)

0.0))

;; Calculate polyline length

(setq polylineLength

(distance (list (car startPoint) (cadr startPoint) 0.0)

(list (car endPoint) (cadr endPoint) 0.0)))

;; Calculate block name

(setq blockName (strcat (rtos (- polylineLength 900) 2 2) "e"))

;; Insert block at the calculated midpoint

(command "_.INSERT" blockName midpoint 1.0 1.0 0.0)

(princ (strcat "\nBlock '" blockName "' placed."))

)

(princ "\nError: Please select a valid polyline.")

)

Re: Please help! Lisp problem

cadffm — Fri, 22 Dec 2023 06:54:12 GMT

Hi,

there is a special forum for Lisp, next door.

> "I only have basic knowledge of coding"

Okay

> "and I used ChatGpt to create this code."

😞

I will not give my full support to beginners-with-chatGPTcode (not good, if you don't know the basics), but:

Look at RTOS

(rtos (- polylineLength 900) 2 2)

Polylineline length = 1922.00000000

result = "1022.00"

You need zero decimal numbers

(setq blockName (strcat (rtos (- polylineLength 900) 2 0) "e"))

Re: Please help! Lisp problem

cadffm — Fri, 22 Dec 2023 07:37:46 GMT

Hi again,

back at my PC I checked the code: It will work! (with my tiny 'rtos' edit)

some comments more

(defun c:TEST nil (setq selectedPolyline (car (entsel "\nSelect a polyline: "))) (if (and selectedPolyline (member (cdr (assoc 0 (entget selectedPolyline))) '("POLYLINE" "LWPOLYLINE"))) ; Allow 2 kind of plines (progn (setq polylinePoints (mapcar 'cdr (vl-remove-if-not '(lambda (x) (= (car x) 10)) (entget selectedPolyline)))) ; will NOT work with POLYLINE objects" ;; Ensure there are at least two points (if (< (length polylinePoints) 2) (princ "\nError: The selected polyline must have at least two points.") (progn (setq startPoint (car polylinePoints)) (setq endPoint (cadr polylinePoints)) ;; Calculate the midpoint (setq midpoint (list (/ (+ (car startPoint) (car endPoint)) 2.0) (/ (+ (cadr startPoint) (cadr endPoint)) 2.0) 0.0)) ;; Calculate polyline length (setq polylineLength (distance (list (car startPoint) (cadr startPoint) 0.0) (list (car endPoint) (cadr endPoint) 0.0))) ;; Calculate block name (setq blockName (strcat (rtos (- polylineLength 900) 2 0) "e")) ;; Insert block at the calculated midpoint ;;;(command "_.INSERT" blockName midpoint 1.0 1.0 0.0) ; Think about running osnaps command statements! (if (or (tblobjname "BLOCK" blockname) (findfile (strcat blockname ".dwg")) ) (command "_.INSERT" blockName "_non" midpoint 1.0 1.0 0.0) (alert (strcat "Block '" blockname "' missing")) ) (princ (strcat "\nBlock '" blockName "' placed.")) ) ) ) (princ "\nError: Please select a valid polyline.") ) )

Re: Please help! Lisp problem

jlee107 — Fri, 22 Dec 2023 07:23:15 GMT

Thank you for your reply and I kinda understand what the problem is now, but lisp still doesn't work and not able to load any type of block. I will ask on special forum.

Re: Please help! Lisp problem

jlee107 — Fri, 22 Dec 2023 07:35:50 GMT

I have changed the code according to your suggestion. I also ran the test to check if it's retrieving proper information with a fixed value such as 8000. It does return as 7100e, but I'm still having the same issue.

Re: Please help! Lisp problem

cadffm — Fri, 22 Dec 2023 07:58:57 GMT

Try my edited code above.

Sample file attached

edit

Is it working now?

new Testfile with three different situations

Another IF to make your program more smart:

something like that:

(IF <length of polyline divideable with 100>

(IF <matching block found>

insert a new blockreference

alert 'Block missing'

)

alert 'Invalid length'

)

Re: Please help! Lisp problem

jlee107 — Fri, 22 Dec 2023 08:01:06 GMT

Thank you! It does work properly like I want it to.