affines

[cjmallan]

what does 'affines' mean

[Big Al1st]

Hi CJ If you mean Affine I can give you a dictionary definition which I cant understand.
If you mean Affined this means joined by kinship or affinity
Rgds Al

[Peter Pedant]

I think they are something in projective geometry

[Big Al1st]

Hi Peter, You are right but its one big mouthful in the dictionary. If CJ wants it I will post it for hern Rgds Al

[Jay_Jay]

Is the word 'aphine'? I think PP has it correctly. Distortion of an image when projected onto a two-dimensional surface?

Like when you get an image of a bicycle symbol, for instance, painted on a road - it's distorted when applied to the road surface but is readable when viewed from the point of view of the motorist.

[Big Al1st]

Hi Jay Jay No there is a word Affine but I am holding out in posting it unless someone wants me too. With my typing it would take me all night. Lol
Bet you will ask me now! If so will tomorrow watching football Take Care

[cjmallan]

not sure how to reply to everyones 'answers' to my question...as this was my very 1st question.
But the context of this word is to do with families/relationships etc just wondered about the origins of 'affines'
thanks

[Big Al1st]

Hi No problems
Affine is to do with mathmatics
Affined is from the French AFFINEmeaning joined by kinship, closely related, neighbouring, allied by marriage

Affine, affinity and affined all come from the same French word. I am afraid I can find no reference to Affines as you asked. Sorry. Rgds Al

[Peter Pedant]

Hi me again

You k n ow if you cut a cone directly across, the base is a circle and if you do it at an angle the base will be an ellipse

I think the circle and the ellipse are related to each other through an affine transformation

The point (ha!) being that the corresponding points on the circle and the ellipse sort of go to the apex of the cone.

and in projective geometry, which sort of goes around as RP2, then the apex of the cone sort of becomes the point of perspective on the horizon.

Having said that, Descartes spent about ten years proving that an ellipse can always be drawn around an irregular hexagon, and now you can see, with an affine transformation, its a regular hexagon and a circle and REALLY easy to prove.

yeah honestly, someone asked what an affine was........

[Big Al1st]

Hi Peter You asked for it

AFFINE Of or pertaining to a mathematical transformation of co-ordinates that is equivalent to a transformation, contraction or expansion with respct to a fixed origin and fixed co-ordinate system.

I suppose that is what you said? lol Rgds Al