Is there a lisp routine available to draw either a circle or rectangle
with a known square yard area?

JPC
A routine like this would draw a circle at whatever size and position

On Sep 4, 11:28 pm, John Callaway <jca... at (no spam) erols.com> wrote:
Is there a lisp routine available to draw either a circle or rectangle
with a known square yard area?

JPC
A routine like this would draw a circle at whatever size and position
specified (in your preferred working units):

; ----- CTEST.LSP -----
; Draw circles by area

(defun C:CTEST()
(setq ar (getreal "Area? "))
(setq pt (getpoint "Centerpoint?"))
(setq rad (sqrt (/ ar pi)))
(command "circle" pt rad)
(princ)
)

Rectangles are a little trickier. Do you have some way of relating the
length of the rectangle to its width?

Is there a lisp routine available to draw either a circle or rectangle
with a known square yard area?

expression: at (no spam) +[sqrt(123),sqrt(123)]

expression: at (no spam) +[sqrt(ar),sqrt(ar)]

Strawberry,
Thanks, that is good for a circle area. I tried to set my units to 9'
(ddunits) so I can get square yards when I run your lisp, but I am
having problems. Can you guide me how to set my units to 9'?

JPC

On Sun, 6 Sep 2009 15:08:46 -0700 (PDT), strawberry



zac.ca... at (no spam) gmail.com> wrote:
On Sep 6, 2:24 pm, John Callaway <jca... at (no spam) erols.com> wrote:
Strawberry,
Thanks, that is good for a circle area. I tried to set my units to 9'
(ddunits) so I can get square yards when I run your lisp, but I am
having problems. Can you guide me how to set my units to 9'?

JPC

Hi John,

Try to avoid top-posting. My provider handles it OK but it drives some
people around here absolutely bananas.

You don't really need to set your units 'to' anything. Although
AutoCAD supports conventions for inputting measurements like [ ' ] for
feet and [ " ] for inches, don't be fooled, AutoCAD really has no
interest in what your preferred units are. The issue only arises when
working with data provided by others. In your case, it seems like
you're working on a drawing drawn in 'feet'. Because there are 3 feet
in a yard just scale the drawing by 1/3rd. If the drawing's in inches
just scale it by 1/(3*12) = 1/36. When you're done using the lisp
command, just scale it back again - or at least make it very apparent
in the drawing that that's what you've done!

Also, I forgot to mention that AutoCAD's RECTANGLE command has of
course already got a feature built-in for drawing rectangles based
upon their area and a known length or width.

Strawberry,
        I posted this below your message, I didn't realize it made any
difference and do apologize. Your lisp works fine. Would it be
possible to tweak it?
        2 issues
1) Could you explain further how I can insert a known area in square
yards when I use the rectang command?
2)  Since I know what my area is in square yards and there are 1296 sq
inches in a square yard, could you modify the lisp you sent  to prompt
for an "area SY"?

JPC

On Sep 7, 1:03 pm, John Callaway <jca... at (no spam) erols.com> wrote:



On Sun, 6 Sep 2009 15:08:46 -0700 (PDT), strawberry

zac.ca... at (no spam) gmail.com> wrote:
On Sep 6, 2:24 pm, John Callaway <jca... at (no spam) erols.com> wrote:
Strawberry,
Thanks, that is good for a circle area. I tried to set my units to 9'
(ddunits) so I can get square yards when I run your lisp, but I am
having problems. Can you guide me how to set my units to 9'?

JPC

Hi John,

Try to avoid top-posting. My provider handles it OK but it drives some
people around here absolutely bananas.

You don't really need to set your units 'to' anything. Although
AutoCAD supports conventions for inputting measurements like [ ' ] for
feet and [ " ] for inches, don't be fooled, AutoCAD really has no
interest in what your preferred units are. The issue only arises when
working with data provided by others. In your case, it seems like
you're working on a drawing drawn in 'feet'. Because there are 3 feet
in a yard just scale the drawing by 1/3rd. If the drawing's in inches
just scale it by 1/(3*12) = 1/36. When you're done using the lisp
command, just scale it back again - or at least make it very apparent
in the drawing that that's what you've done!

Also, I forgot to mention that AutoCAD's RECTANGLE command has of
course already got a feature built-in for drawing rectangles based
upon their area and a known length or width.

Strawberry,
        I posted this below your message, I didn't realize it made any
difference and do apologize. Your lisp works fine. Would it be
possible to tweak it?
        2 issues
1) Could you explain further how I can insert a known area in square
yards when I use the rectang command?
2)  Since I know what my area is in square yards and there are 1296 sq
inches in a square yard, could you modify the lisp you sent  to prompt
for an "area SY"?

JPC

1.
; ----- RECTEST.LSP -----
; Draw rectangles by area (in square yards) and one known length (in
yards)

(defun C:RECTEST()
(setq ar (getreal "AreaSY? "))
(setq ar (* ar 1296))
(setq len (getreal "LengthY? "))
(setq len (* len 36))
(setq pt (getpoint "Cornerpoint?"))
(command "rectangle" pt "a" ar "l" len )
(princ)
)

2.
; ----- CTEST.LSP -----
; Draw circles by area (in square yards)

(defun C:CTEST()
(setq ar (getreal "AreaSY? "))
(setq ar (* ar 1296))
(setq pt (getpoint "Centerpoint?"))
(setq rad (sqrt (/ ar pi)))
(command "circle" pt rad)
(princ)
)

On Sep 6, 2:24 pm, John Callaway <jca... at (no spam) erols.com> wrote:
Strawberry,
Thanks, that is good for a circle area. I tried to set my units to 9'
(ddunits) so I can get square yards when I run your lisp, but I am
having problems. Can you guide me how to set my units to 9'?

JPC


Hi John,

Try to avoid top-posting. My provider handles it OK but it drives some
people around here absolutely bananas.

You don't really need to set your units 'to' anything. Although
AutoCAD supports conventions for inputting measurements like [ ' ] for
feet and [ " ] for inches, don't be fooled, AutoCAD really has no
interest in what your preferred units are. The issue only arises when
working with data provided by others. In your case, it seems like
you're working on a drawing drawn in 'feet'. Because there are 3 feet
in a yard just scale the drawing by 1/3rd. If the drawing's in inches
just scale it by 1/(3*12) = 1/36. When you're done using the lisp
command, just scale it back again - or at least make it very apparent
in the drawing that that's what you've done!

Also, I forgot to mention that AutoCAD's RECTANGLE command has of
course already got a feature built-in for drawing rectangles based
upon their area and a known length or width.

Thanks, that is good for a circle area. I tried to set my units to 9'
(ddunits) so I can get square yards when I run your lisp, but I am
having problems. Can you guide me how to set my units to 9'?

Try to avoid top-posting.

1.
; ----- RECTEST.LSP -----
; Draw rectangles by area (in square yards) and one known length (in
yards)

(defun C:RECTEST()
(setq ar (getreal "AreaSY? "))
(setq ar (* ar 1296))
(setq len (getreal "LengthY? "))
(setq len (* len 36))
(setq pt (getpoint "Cornerpoint?"))
(command "rectangle" pt "a" ar "l" len )
(princ)
)

2.
; ----- CTEST.LSP -----
; Draw circles by area (in square yards)

(defun C:CTEST()
(setq ar (getreal "AreaSY? "))
(setq ar (* ar 1296))
(setq pt (getpoint "Centerpoint?"))
(setq rad (sqrt (/ ar pi)))
(command "circle" pt rad)
(princ)
)

BTW, although I'm not the world's worst lisp programmer, I'm
definitely a contender for that prize, so feel free to have a go at
this stuff yourself!

1.
; ----- RECTEST.LSP -----
; Draw rectangles by area (in square yards) and one known length (in
yards)

(defun C:RECTEST()
(setq ar (getreal "AreaSY? "))
(setq ar (* ar 1296))
(setq len (getreal "LengthY? "))
(setq len (* len 36))
(setq pt (getpoint "Cornerpoint?"))
(command "rectangle" pt "a" ar "l" len )
(princ)
)

2.
; ----- CTEST.LSP -----
; Draw circles by area (in square yards)

(defun C:CTEST()
(setq ar (getreal "AreaSY? "))
(setq ar (* ar 1296))
(setq pt (getpoint "Centerpoint?"))
(setq rad (sqrt (/ ar pi)))
(command "circle" pt rad)
(princ)
)

BTW, although I'm not the world's worst lisp programmer, I'm
definitely a contender for that prize, so feel free to have a go at
this stuff yourself! :-)

        The circSY lisp works great! However I have trouble with the
rectangSY lisp. Is there a way to just have the prompt ask only for
the Square Yards? When I enter the sy it then asks for one corner then
another which then will not be the square yards I entered.
        I cleaned out the rest of the thread to improve my protocol.

JPC    

It works fine on my machine (XP running AutoCAD2008). Your version
must be a little different.
Run through the rectang command (using the area option - and not using
my rectest routine) and post the results here, e.g.:

Command: rec RECTANG
Specify first corner point or [Chamfer/Elevation/Fillet/Thickness/
Width]: [User clicks point on screen]
Specify other corner point or [Area/Dimensions/Rotation]: a
Enter area of rectangle in current units <129600.0000>: 100

Calculate rectangle dimensions based on [Length/Width] <Length>: l

Enter rectangle length <360.0000>: 10

        Lengths & widths are not  factors at all.

        Lengths & widths are not  factors at all.

!?!

So you'd be just as happy with a square?

On Wed, 9 Sep 2009 00:19:58 -0700 (PDT), strawberry

zac.ca... at (no spam) gmail.com> wrote:
        Lengths & widths are not  factors at all.

!?!

So you'd be just as happy with a square?

I never really thought about that, but yes, that is correct.