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revised How did the rule of addition come to be and why does it give the correct answer when compared empirically?
Grammar fix
Jan
9
comment Find the volume of the solid formed by rotating about the $x$-axis
@JohnMolokach $e^0 = 1$ by definition...
Jan
8
awarded  Nice Answer
Dec
23
comment Is there a name for this expression?
@Ian in that case you can symmetrize $K$, $K' = \frac12(K+K^T)$ and call it the $K'$ (semi-)norm on said subspace.
Dec
23
comment Is there a name for this expression?
@Ian my bad about semidefiniteness. About the definedness: that subset will always be a subspace (in the finite-dimensional case), so I'd call that subspace "the space where $V$ comes from".
Dec
23
comment Is there a name for this expression?
@PeterFranek There's a 15 minute wait time afaik.
Dec
23
comment Is there a name for this expression?
And in any case. using $K$ it can be written as $\sqrt{V^TKV}$. The given quantity is only defined if $K$ is positive definite on the space where $V$ comes from.
Dec
23
comment Is there a name for this expression?
I removed the numerical-linear-algebra tag since it's not relevant to the question. Please read the tag description before applying a tag.
Dec
23
revised Is there a name for this expression?
edited tags
Nov
19
comment Given two matrices A and B, compute the convolution mask sending A to B?
You forgot your own constraints on $K$. In your OP you wrote the corner elements are $0$, you named them $x_1, x_3, x_7, x_9$. Now that I look at it, you can't really conclude $x_3 = x_7 = 0$ from anywhere unless that's a given, but they must be equal so you would need one additional set of equations to find them.
Nov
18
comment Given two matrices A and B, compute the convolution mask sending A to B?
@working Done. Does it help?
Nov
18
revised Given two matrices A and B, compute the convolution mask sending A to B?
added 347 characters in body
Nov
18
comment Given two matrices A and B, compute the convolution mask sending A to B?
It doesn't follow from anything but the "value" of $A$. $A^T$ is the transpose of $A$.
Nov
18
comment Given two matrices A and B, compute the convolution mask sending A to B?
Ummm, none of these are identity matrices. But they are both symmetric ($A=A^T$ and $B=B^T$).
Nov
18
answered Given two matrices A and B, compute the convolution mask sending A to B?
Nov
16
comment Which statistic test for difference in downloads per week?
@Ansjovis86 You would have many more weeks. The problem is that your current sample size is 2. All you could say here is that week1 happens to only have a third of the downloads if week2, but no explanation for it. You first need assumptions (such as the number of downloads is uniformly distributed among the days of week, but per week there's pattern XYZ) Then you can test this specific hypothesis. The problem at hand is that it's very hard to generate meaningful hypotheses from such a small sample.
Nov
16
comment Which statistic test for difference in downloads per week?
You need much more data if you want any kind of significant result. Also, you might want to check out Cross Validated, our sister site about statistics.
Nov
16
comment Limit of an integral that resembles the Riemann-Lebesgue Lemma
Please do not use titles consisting only of math expressions; these are discouraged for technical reasons -- see meta.
Nov
16
revised Limit of an integral that resembles the Riemann-Lebesgue Lemma
edited title
Nov
16
comment Colour of bear in Earth's surface
+1 for the family of south-pole solutions ;)