Reputation
652
Top tag
Next privilege 1,000 Rep.
Create new tags
Badges
5 14
Impact
~27k people reached

Aug
30
awarded  Popular Question
Aug
16
comment Convex Quadrilateral Test
This looks like an efficient solution. I have finally used Cramer's Rule to check whether intersection of diagonals lays inside the quadrilateral.
Mar
7
revised Derivative of inverse function where inverse is known only numerically.
deleted 18 characters in body
Mar
7
answered Derivative of inverse function where inverse is known only numerically.
Mar
7
revised Derivative of inverse function where inverse is known only numerically.
edited title
Mar
7
comment Derivative of inverse function where inverse is known only numerically.
I don't see how it's trivial. The forward derivative is already a third degree polynomial in $x$. The inverse can be computed only numerically so it seems I need a special numerical approximation routine for $f^{-1}(y,a)$ as $y$ depends on $a$ and we don't have the information on how it depends on it...
Mar
7
revised Derivative of inverse function where inverse is known only numerically.
added 63 characters in body
Mar
7
comment Derivative of inverse function where inverse is known only numerically.
But I computed the inverse without problem numerically. I only need to compute it more precisely using some formula. Please note that I also care about partial derivative only (w.r.t. a), not in both variables (the x can be considered fixed). Such function can be plotted and I can see it has inverse (graphically), but I need the formula...
Mar
7
comment Derivative of inverse function where inverse is known only numerically.
One problem is that it is impossible to compute $J^{-1}$ in this case because it is a non-square matrix ($1\times 2$).
Mar
7
comment Derivative of inverse function where inverse is known only numerically.
I found it, thanks.
Mar
7
comment Derivative of inverse function where inverse is known only numerically.
I was looking for that without success (using keyword "multivariable inverse function theorem"). I found something called "implicit function theorem" but I am not sure if this is it nor how to apply it.
Mar
7
asked Derivative of inverse function where inverse is known only numerically.
Feb
25
revised Inverse function theorem for partial derivatives of a vector function
added 31 characters in body
Feb
25
answered Inverse function theorem for partial derivatives of a vector function
Feb
25
revised Inverse function theorem for partial derivatives of a vector function
added 3 characters in body
Feb
25
revised Inverse function theorem for partial derivatives of a vector function
deleted 477 characters in body
Feb
25
revised Inverse function theorem for partial derivatives of a vector function
removed wrong example
Feb
25
suggested approved edit on Inverse function theorem for partial derivatives of a vector function
Feb
25
revised Inverse function theorem for partial derivatives of a vector function
Added example
Feb
25
suggested approved edit on Inverse function theorem for partial derivatives of a vector function