21,262 reputation
23379
bio website
location
age 29
visits member for 4 years, 3 months
seen 25 mins ago

May
10
comment On the semantics of the gamma distribution
I see, but what do you do mathematically with the probability distribution of the so-called detection probability?
May
10
comment On the semantics of the gamma distribution
I dare say the gamma distribution describes the value of noise at any pixel, not the probability of its existence, whatever that may mean. If you don't mind me saying, something seems fishy about the way you are going about this. How do you intend to use these probabilities?
May
10
comment On the semantics of the gamma distribution
...You have a probability distribution over the probabilities of noise? That seems redundant at best. And why do you believe that this is best modelled by a gamma distribution in the first place?
May
10
comment Correlation Coefficient and Determination Coefficient
It might help if you define the terms in your question. What is the equation for $R^2$, in particular?
May
10
comment On the semantics of the gamma distribution
Given the shape of the gamma distribution, I don't see how you can get either of them anywhere close to 1 while simultaneously keeping 98% of the mass between 0 and 1... unless $k$ is really high, in which case there won't be much of a difference between $\theta k$ and $\theta (k-1)$. Can you elaborate on what you are really trying to achieve by varying the parameters of the distribution?
May
10
answered On the semantics of the gamma distribution
May
10
revised Three-dimensional art galleries
added 253 characters in body
May
10
answered Three-dimensional art galleries
May
10
comment Optimizing a Composed Function
For all $x$ and $y$ in $\mathbb R^n$, $f(x) \le f(y)$ if and only if $g(f(x)) \le g(f(y))$, so yes.
May
9
comment Wrapping polyhedral of a volumetric mesh
Oh, is this a volumetric mesh? I've always heard the term "hexahedral mesh" used in this context, rather than "6 faced elements". But in that case I don't understand how removing certain nodes and elements would leave you with a polyhedron rather than a smaller collection of volumetric elements. (Perhaps you could include a diagram to show an example mesh and what output you expect to get?)
May
9
comment Wrapping polyhedral of a volumetric mesh
Can you explain your question more clearly? I cannot understand what you mean by a "wrapping polyhedral" or what "6 faced elements" are.
May
9
comment Achilles and the tortoise paradox?
Does it really make physical sense to speak of a turtle that can turn a right angle in arbitrarily small intervals of time? This is like saying, I put a ball in the box at time $t = 0$, take it out of the box at $t = 0.9$, put it back in at $t = 0.99$, take it out at $t = 0.999$, and so on; is the ball in the box at $t = 1$? The scenario described is impossible in real life. I feel that you have stretched this paradox past its breaking point.
May
9
comment Achilles and the tortoise paradox?
What you've done is exhibited an infinite sequence of times at which you are ahead of me. But since that sequence doesn't extend all the way into the future, your logic says nothing about whether you remain ahead of me at any time after all the times in your sequence.
May
9
comment Distance between points in a convex set and outside of a convex set.
I edited your answer to replace $<, >$ with $\langle, \rangle$. Hope that's OK.
May
9
revised Distance between points in a convex set and outside of a convex set.
changed $<, >$ to $\langle, \rangle$
May
8
comment Is the expectation of a probability distribution the point on which a physical cutout of the distribution would balance?
A spike in the pmf is a point mass. That's not too hard to imagine; you just think of putting a small heavy lead weight on top of your infinitely light wooden board.
May
8
comment Derivation of the derivative of a square matrix w.r.t. a vector
What you're looking for is called the Jacobian matrix. You should be able to apply the definition given there to get the expected answer.
May
7
comment What is the proper name for this number system?
There's also a sign change somewhere along the line; the OP has $ij = k$ but Wikipedia has $ik = -j$.
May
7
comment Infinitesimals in the denominator
Surely you've made a mistake in the derivation. The $4$'s should cancel out when you subtract $y(x_0)$ from $y(x_0+\Delta x)$.
May
7
answered What does an inverse matrix abstracts?