Drawing Sine/Cosine Waves, Any thoughts?

[harrison-matt]

All,

 

Before i start bashing my head on the desk reverting back to old trig, is there anywone with neat suggestions to drawing a cosine wave between two points?

 

 

Matt

[lpseifert]

Save a desk... have a look here

http://www.cadalyst.com/cad/autocad/autolisp-solutions-draw-a-sinusoidal-curve-a-spline-or-polyline-5120

[BlackBox]

Use the getint, getpoint (with an (initget 32) twist), distance, angle, and polar functions..?

 

Oh! And for kicks, throw in a little lambda+mapcar combo on the side (to handle any curve frequency). :wink:

[BlackBox]

Save a desk... have a look here

http://www.cadalyst.com/cad/autocad/autolisp-solutions-draw-a-sinusoidal-curve-a-spline-or-polyline-5120

 

I didn't see your post until I was done typing mine, great link, Larry!

[harrison-matt]

I like this function however, I am really trying to find out how to draw one by specifying two points.

The ratio of Period to Amp i am looking forward is 2:0.5

and i would like to be able to specify the Amp

[BlackBox]

I like this function however, I am really trying to find out how to draw one by specifying two points.

The ratio of Period to Amp i am looking forward is 2:0.5

and i would like to be able to specify the Amp

 

See post #3.

[harrison-matt]

Do you think a Spline or polyline should be the victom of this command?

[David Bethel]

 (initget 7)
 (setq amp (getdist "\nAmplatude:   "))
 (initget 7)
 (setq frq (getdist "\nFrequency:   "))
 (initget 6)
 (setq rep (getint "\n# of Points per Wave <1000>:   "))
 (and (not rep)
      (setq rep 1000))
 (setq i 0
     inc (/ (* 2 pi) rep))
 (command "_.PLINE")
 (repeat (1+ rep)
     (command (list (* i frq) (* amp (sin i))))
     (setq i (+ i inc)))
 (command "")

 

 

-David

[Lee Mac]

Another 'fun' one

 

(defun c:DynFun ( / _GenerateFunctionPoints fun p1 gr )
 ;; © Lee Mac 2010

 ;; Function to evaluate
 (setq fun sin)

 (defun _GenerateFunctionPoints ( p1 p2 / d a1 a2 i j )
   (setq d (distance p1 p2) a1 (angle p1 p2) a2 (+ a1 (/ pi 2.)) i 0 p3 (polar p1 a2 (fun 0.)))

   (while (<= (setq x (* 0.1 (setq i (1+ i)))) d)
     (grdraw p3 (setq p3 (polar (polar p1 a1 x) a2 (fun x))) 3)
   )
 )

 (if (setq p1 (getpoint "\nSpecify First Point: "))
   (while (= 5 (car (setq gr (grread 't 13 0)))) (redraw)
     (_GenerateFunctionPoints p1 (cadr gr))
   )
 )
 
 (princ)
)

Could work with any function

 

 

I like this one

 

(setq fun (lambda ( x ) (* (sin (* 2.0 x)) (exp (/ x 10.0)))))

[BlackBox]

Another 'fun' one

 

 

Lee, DynFun is really neat.

 

(fun 2) is also cool. :wink:

[Lee Mac]

Glad you like it Mr Render

[harrison-matt]

Lee,

 

That is really cool! Grread is pretty sweet! i'll keep trying on my end and will post my attempts and errors here.

 

David, thanks for the tips.

 

Thanks,

Matt

[Lee Mac]

That is really cool! Grread is pretty sweet! i'll keep trying on my end and will post my attempts and errors here.

 

Grread is great for visual effect, but useless for practical applications as you have no OSnap, Ortho, Tracking or any other standard functionality. GrRead is purely for tracking keystrokes, mouse movements - general user input. Any OSnap or other functionality must be imitated within the grread loop.

 

Lee

[AHMEDSAL]

This is awosome and exactly what i want, drawing sin wave controlling amplitude decreasing increasing i am doing some FEA project

 

but life cant be awsome like that always cause i got this error

 

SINECURVE - Error: quit / exit abort

SYSTEM VARIABLES have been reset

 

i googled the system variables thing but never got an answer beside the original forum is closed down and i cant get to Tony the man how come up with it ....please if any one know any thing on how to fix this error in 2011 i would really appreciated

 

I am attaching the files for the SINCURVE function if you can do anything to fix the errors please

0305.lsp

0305alspsol-sinecurve.dcl

[marko_ribar]

Here, I've corrected error (it was name of *.dcl - you should not rename file as it was written - should be sinecurve.dcl)... Anyway, I've incorporated dcl into lsp and you don't have to store it in support search path of ACAD - you can load it from anywhere - it should work - creates temp dcl file, use that dcl and at the end removes temp dcl...

 

Regards, M.R.

sinecurve.lsp

[raed]

I know this is a super old topic, but I've been looking for something like this.

 

I ended up coming to my own solution for parametric sine/cosine waves using contiguous ellipse arcs with an apparatus of parametric construction geometry to define osnaps for each axis of the unit arc.

 

However the only parameters I could figure out to create, and which I think might exist with a setup like this, are the amplitude and frequency - no damping or anything like that.

 

Additionally I just came across this: https://www.cadstudio.cz/en/apps/2dplot/, which looks like it might be really for providing appropriate fidelity and additional parameters such as damping.

sine_generator.dwg

Edited November 2, 2020 by raed
not quadrants