2
$\begingroup$

RotationTransform has options RotationTransform[{u,v},p]

gives a rotation about the point p that transforms u to the direction of v.

But why there is only Rotate[g,{u,v}]

How to set the point p in Rotate?

Improve this question
$\endgroup$
8
  • 5
    $\begingroup$ But there is a third argument (coordinate list} for Rotate which does just that... $\endgroup$
    – Yves Klett
    Commented Nov 10, 2015 at 17:28
  • $\begingroup$ @YvesKlett I can't find it, which option do you mean? $\endgroup$
    – matheorem
    Commented Nov 11, 2015 at 0:56
  • $\begingroup$ reference.wolfram.com/language/ref/Rotate.html $\endgroup$
    – Yves Klett
    Commented Nov 11, 2015 at 6:39
  • $\begingroup$ @YvesKlett Er... I am really stupid now. But I can't find the exact same thing like RotationTransform[{u,v},p]. There is only Rotate[g,{u,v}] but without a reference point. And Rotate[g,θ,{u,v}] is totally different thing. Would you help me again? $\endgroup$
    – matheorem
    Commented Nov 11, 2015 at 7:08
  • $\begingroup$ From the help: "Rotate[g,θ,{x,y}] rotates about the point". $\endgroup$
    – Yves Klett
    Commented Nov 11, 2015 at 8:06

1 Answer 1

Reset to default
3
$\begingroup$

You could translate the figure being rotated back and forth.

GeometricTransformation[g, RotationTransform[{u, v}, p]]

is equivalent to

Translate[Rotate[Translate[g, -p], {u, v}], p]

For example,

u = {1, 0};
v = {1, 1/5};
p = {1/3, 1/3};
g = Rectangle[];
Graphics[GeometricTransformation[g, RotationTransform[{u, v}, p]], Axes -> True]
Graphics[Translate[Rotate[Translate[g, -p], {u, v}], p], Axes -> True]

rotated rectangle

This works in both 2D and 3D.

Improve this answer
$\endgroup$
1
  • $\begingroup$ Rotate[g, VectorAngle[u, v], p] $\endgroup$
    – yode
    Commented Jan 28, 2016 at 4:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.