Message Boards Message Boards

Solve goes into infinite loop, when solving a quadratic equation system

I have written a program for the principal axis transformation of quadrics in matrix form with homogeneous coordinates. The Solve command goes into an infinite loop in the third function call of "principalAxisMat" with matrix "A3". It fails to solve a system of quadratic equations in exact form. Is this a failure of Wolfram Mathematica or is this my fault?

Attachments:
principalAxis-03.nb
principalAxisMat.wl
POSTED BY: Ralph Trenkler
2 Replies
Sort By:

Not that I would go about it in this way, but if I did, I would change this construct:

Solve[Thread[Chop[Flatten[Transpose[T1s] . As . T1s -
                   B1s]]==ConstantArray[0,n*n]],...]

Since T1s is constructed to be orthogonal, you can make the system linear by multiplying through by Transpose[T1s].
POSTED BY: Daniel Lichtblau

Try with:

 A3 = Transpose[T30] . A30 . T30 // FullSimplify

I don't know why it works with FullSimplify.

I tried with Mathematica 13.0.
POSTED BY: Mariusz Iwaniuk
Reply to this discussion
Community posts can be styled and formatted using the Markdown syntax.
Tag limit exceeded
Note: Only the first five people you tag will receive an email notification; the other tagged names will appear as links to their profiles.
Reply Preview
Attachments
Remove
or Discard

Group Abstract Group Abstract