Hi,

V5

three lines and need elipse tan to them, but I see no elipse tan to 3 command.

As its possible, or so my vision thinks, how is it done ?

elipse tan to lines3.3dm (36.2 KB)

Cheers

Steve

Hi,

V5

three lines and need elipse tan to them, but I see no elipse tan to 3 command.

As its possible, or so my vision thinks, how is it done ?

elipse tan to lines3.3dm (36.2 KB)

Cheers

Steve

There are an infinite number of ellipses o different eccentricities which are tangent to three curves. Steve, will any ellipse work or are there other requirements such as eccentricity?

Hi,

V5

eccentricities, blimey elipses with attitude …or character !

I am happy for any elipse to fit on this occasion.

I must look up what eccentric elipses are when I get 5 mins

Steve

The eccentricity of an ellipse is the ratio of the major axis length to the minor axis length of the ellipse.

I think a circle counts as a ‘special’ kind of ellipse, right? If that counts in your case, there’s already a circle tangent to 3 curves tool.

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A circle is an ellipse with an eccentricity of 1. So if the only requirement is three lines and an ellipse then a circle is a valid answer, and as good as any other ellipse.

Steve’s example with a circle/ellipse fitted using the Circle command and tangent option:

Hi, yes there is a circle tan tan tan but I do need an elipse on this occasion.

Cheers

Steve

@Steve1 Here are a few of the infinite number of ellipses which are tangent to your example lines.

More information/constraints are needed to define the ellipse. The eccentricity and direction of major axis; eccentricity and an additional line; or additional line and direction of major axis may be sufficient to define the ellipse but there is no guarantee that an ellipse will fit any arbitrary set of constraints. More information about the problem you are trying to solve would be helpful.

The suggestion by @phcreates to use Scale1D is brilliant.

The direction of the 1D scaling determines the orientation of the ellipse, and the amount of scaling determines the eccentricity.

Draw a line parallel to the desired orientation of the ellipse.

Place three points on the line with the ratio the distance between point 1 and point 2 to the distance between point 1 and point 3 equal to the desired eccentricity.

`Scale1D`

the lines with Copy=Yes. 1 is base, 3 is first reference point, 2 is second reference point.

`Circle`

with Tangent option. The scaled lines are the tangent lines.

`Scale1D`

the circle. 1 is the base, 2 is the first reference point, 3 is the second reference point.

1 Like

Hi,

The elipse I was after was something of the type as marked here.

Cheers

Steve

So the solution I sent should work, right?

You can make an ellipse like that one using the method I described above with a vertical helper line and three points on the line.