LISP programming help

[acadstudent]

Hello, I am new to LISP and programming in general and stuck with an issue. I am to create a program that will calculate the area and volume ofa 3D box.

 

Input:

Enter width of 3D Box:

Enter depth of 3D Box:

Enter height of 3D Box:

 

Output:

-------------------------------------------------

Box Statistics

-------------------------------------------------

Box Width: XX.XXXX

Box Depth: XX.XXXX

Box Height: XX.XXX

Box Surface Area: XX.XXXX square inches

Box Volume: XX.XXXX cubic inches

-------------------------------------------------

 

Algorithms: V=w*d*h

SA= 2(hd + dw + hw)

 

Now here is what I have as far as drawing the 3D box, I understand mostly how to figure the W/D/H of both and such, but I'm having trouble figuring out best way to make these all print how they should and look correct. Any help is appreciated.

 

 

(defun C:3DBOX ( / )

 

(setq SP (getpoint "\nPick Starting Point of Box: "))

(setq L (getreal "\What is the Length of the box? "))

(setq W (getreal "\What is the Width of the box? "))

(setq H (getreal "\What is the Height of the box?

 

(command ".box" SP "L" L W H )

 

);eop

[MSasu]

Please look for PRINT, STRCAT and RTOS functions.

[ymg3]

Acadstudent,

 

Are you familiar with reverse polish notation ?

 

You seem to be stuck there. This is among the first thing you will need to get familiar with

 

(setq v (* w d h)                             ;  V = w * d * h           
(setq sa (*  2  (+ (* h d) (* d w) (* h w)))  ;  SA = 2(hd + dw + hw)

 

ymg

[acadstudent]

Okay so I should set up something like:

 

(setq BW "L" BD "W" BH "H" BSA "(* ( + (* BH BD) (* BD BW) (* BH BW) ) 2)" BV "( * BW BD BH)" )

 

(strcat "Box Width: " BW)

(strcat "Box Depth: " BD)

(strcat "Box Height: " BH)

(strcat "Box Surface Area: " BSA)

(strcat "Box Volume: " BV)

 

Does this look like the right idea?

[MSasu]

As already told you, you should look for RTOS to convert a number into a string. By using your way you set those variables to strings; to understand just test this into console/command prompt:

(progn
(setq aa 1.2345)
(print "aa")
(print (rtos aa 2 4))
)

 

Presuming that L, W and H were the ones defined into your previous post, then:

(setq BSA (* (+ (* H W) (* W L) (* H [color=red]L[/color])) 2)
     BV  (* L W H))
(print (strcat "Box Width: " (rtos L 2 3)))

Please edit your post and add the code tags!

[acadstudent]

I have taken you advice and changed my code as mentioned. I'm still not getting the correct returns, but I appreciate all the help in getting there. Here is what I have thus far:

 

(defun C:3DBOX ( / )


 (setq SP  (getpoint "\nPick Starting Point of Box: ")) ;Starting 
Point of box
 (setq W  (getreal "\What is the Width of the 
box? "));Box Length           

 (setq D  (getreal "\What is the Depth of the box? ")) ;Box 
Width            

 (setq H  (getreal "\What is the Height of the box? "));Box 
Height           


 (command ".box" SP "L" L W H "" )


 (setq BW W BD D BH H BSA (* (+ (* H W) (* W L) (* H L)) 2) BV ( * D W 
H) )


(print
(strcat "Box Width: " (rtos W 2 3))
(strcat 
"Box Depth: " (rtos D 2 3))
(strcat "Box Height: " (rtos H 2 
3))
(strcat "Box Surface Area: " (rtos BSA 2 3))
(strcat "Box 
Volume: " (rtos BV2 3))
)
 


 );eop

 

 

thanks again!

Student

[BIGAL]

Just a bit simpler to see whats going on

 

 

(setq BW W BD D BH H BSA (* (+ (* H W) (* W L) (* H L)) 2) BV ( * D W 
H) )


(setq BW W 
BD D 
BH H 
BSA (* (+ (* H W) (* W L) (* H L)) 2) 
BV ( * D W H) 
)

[MSasu]

Seems that you changed the L variable to D, but didn't adjusted the code accordingly. I have did some corrections and commented them:

 

(defun C:3DBOX( / [color=red]SP W D H BSA BV[/color] )   [color=blue];;get used to localize variable - to avoid conflicts with other functions[/color]
[color=blue] ;;ensure user input[/color]
(if [color=red](and [/color]
     (setq SP (getpoint "\nPick Starting Point of Box: "))   ;Starting Point of box
     (setq W  (getreal "\[color=red]n[/color]What is the Width of the box? "))  ;Box Length
     (setq D  (getreal "\[color=red]n[/color]What is the Depth of the box? "))  ;Box Width
     (setq H  (getreal "\[color=red]n[/color]What is the Height of the box? ")) ;Box Height
    [color=red])[/color]
[color=red] (progn[/color]
  [color=blue];;get used to take care of localized AutoCAD[/color]
  (command "[color=red]_[/color].box" SP "L" W [color=red][b]D[/b][/color] H)   [color=red];;order of edge dimensions ?!?[/color]

  [color=blue];;don't need to change variables name, it just make debug harder!!! [/color]
  (setq BSA (* (+ (* H W)
                  (* W D)
                  (* H D)) 
               2)
        BV  (* D W H))

  [color=blue];;switch to text window for report[/color]
[color=red]  (textscr)[/color]
  [color=blue];;PRINT/PROMPT accept only one argument!!![/color]
  (prompt (strcat "[color=red]\n[/color]Box Width:        " (rtos W 2 3))[color=red])[/color]   [color=blue];;print each to new line[/color]
  [color=red](prompt [/color](strcat "[color=red]\n[/color]Box Depth:        " (rtos D 2 3))[color=red])[/color]
  [color=red](prompt [/color](strcat "[color=red]\n[/color]Box Height:       " (rtos H 2 3))[color=red])[/color]
  [color=red](prompt [/color](strcat "[color=red]\n[/color]Box Surface Area: " (rtos BSA 2 3))[color=red])[/color]
  [color=red](prompt [/color](strcat "[color=red]\n[/color]Box Volume:       " (rtos [color=red]BV 2[/color] 3)))   [color=blue];;missed a space[/color]
[color=red]  )
)[/color]

[color=red] (princ) [/color]  [color=blue];;exit silent[/color]
);eop

You may want also to look for GETDIST instead of GETREAL to allow for interactive input.

[acadstudent]

MSasu,

 

Thank you, that makes sense, and I appreciate how you marked up where I made some mistakes, that helps me to realize and see where the issues were. This program works beautifully now! I added in the "Cubic Inches" and "Square Inches" text after the formulas in the rtos functions to complete it. I am curious though if there is a way to return a leading "0" in front of any single digit returns. Example being: if the user inserts 5 as the Width of the box, when that it returned it is returned as:

 

5.000

 

I thought that the 2 3 following the W/D/H/BSA/BV would take care of this, however it does not seem to. Any thoughts? Again I appreciate all of your help and will be posting many more questions as I realize this forum is extremely helpful to learning quickly!

 

Thank you again!

Acadstudent

[MSasu]

You're entirely welcome!

 

For printing those zeros, you will need to play with DIMZIN system variable and RTOS arguments. It should be set to 0 to get the trailing zeros:

(rtos 2.5 2 4) ;this will return "2.5000" for DIMZIN = 0

A good programming practice is to restore user's environment after affecting it:

(defun MyFunction( / oldDimZin )
...
(setq oldDimZin (getvar "DIMZIN"))   ;retain current state of the system variable
(setvar "DIMZIN" 0)                  ;force display of trailing zeros
...
do your prints
...
(setvar "DIMZIN" oldDimZin)          ;restore the system variable

(princ)
)

Edited December 9, 2013 by MSasu