Drawing Parabolic Curve

Hello group,

I have a request from a customer to draw a specific parabola curve
described as follows: Y=X squared / 4P. Where P = 6.

Anybody knows how to do that?

Thanks,

Jeannette

 

Dish antenna?

Bob

 

select a value for x calculate y
X=-1
P=6
Y=(x*x)/(4*P)
Y=(-1*-1)/(4*6)
Y=1/24

X=0
P=6
Y=(x*x)/(4*P)
Y=(0*0)/(4*6)
Y=0/24
Y=0

X=1
P=6
Y=(x*x)/(4*P)
Y=(1*1)/(4*6)
Y=1/24

X=2
P=6
Y=(x*x)/(4*P)
Y=(2*2)/(4*6)
Y=4/24

so the command is draw single point
enter the location if x=1 then
1,1/24
if x=2 then
2,4/24
if x=3 then
3,9/24
etc.
connect the dots with polyline arcs.
the closer the dots to each other the more accurate the curve.

Bob

 

or connect the dots with a spline

 

Hello,

There is a a little program (20 years old) to draw parabolic curves at
http://www.martinvogel.de/prog/marvolisp.html - you can download the
marvolisp.zip file, extract it into your AutoCAD's support directory
and start the program with the command !(load "parabel.lsp") and then
"parabel".

Martin

 

There is also a program called Z-grapher (freeware) which will do any
functional, parametric or polar graph, and can export to a rastered
format by copying and pasting. For this, I use Irfanview.
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