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## Using enable_if, in class template method, to check if two function arguments arguments are both std::array or both std::vector

I am not a professional coder and I apologise if my question seams naive or malformed. I am trying to have a class member function take std::array or std::vector in the arguments. Specifically I am passing two arguments that should either both be std::array or both be std::vector. BEFORE trying to make the above work, […]

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## Upper-Bound on the number of local maximums in sum of quasi-concave functions

Is there any approach to find a good upper-bound on the number of modes (local maximums) in the sum of several quasi-concave functions? What is the tightest upper-bound? I’m very interested to know whether it is possible to find better bounds by considering some constraints on the functions. For example, in special cases, it can […]

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Let $(X, \mathcal{B}, \mu, S)$ and $(Y, \mathcal{C}, \nu, T)$ be invertible probability-measure-preserving systems, with a measurable factor map $\pi: X \to Y$, i.e. $\pi \circ S = T \circ \pi$. Suppose that there is some $N \in \mathbb{N}$ such that $\nu$-almost every $y \in Y$ has at most $N$ preimages under $\pi$, i.e. $\# […] Categories ## Can I use SVD to find complex eigenvectors from complex eigenvalues? Assume that we have a real square matrix$A$and we know its eigenvalues. Let’s assume that matrix$A$is A = [0.018142, 0.968856, 0.151740, 0.757174, 0.017829, 0.474323, 0.358832, 0.970854, 0.184523, 0.063063, 0.680511, 0.191901, 0.806877, 0.830208, 0.977169, 0.222291]; And the eigenvalues are eigs = [1.87922 + 0.00000i -0.45009 + 0.11680i -0.45009 – 0.11680i 0.41623 + […] Categories ## Take a ten minute walk I’m pretty new at coding and I am doing a Codewars test in which my code had this results: Time: 837ms Passed: 1 Failed: 3 Exit Code: 1 Test Results: Test Passed should return False should return False should return False I don’t know why my code doesn’t pass everything but it has passed in […] Categories ## what is the idea to calculate this integral i have to calculate$G(t,s)=\int_0^{+\infty} G_1(t,\tau) \times G_2(\tau, s) d\tau$where$G_1(t,\tau)=\begin{cases} f_1(t,\tau),\, t<\tau\\ f_2(t,\tau),\,\, \tau<t\end{cases}$and$G_2(\tau,s)=\begin{cases} g_1(\tau,s),\, s<\tau\\ g_2(\tau,s),\,\, \tau<s\end{cases}$how to calculate$G(t,s)$, how to de with the cases$s<\tau$and$\tau<s$? thank you Categories ## Null space of square matrix$A\$ by using Gaussian Elimination – How?

I have a matrix: $$A = \begin{bmatrix} 23.941& 30.000& 20.000& 14.000 \\ 30.000& 49.941& 32.000& 49.000\\ 20.000& 32.000& 20.941& 32.000\\ 14.000& 49.000& 32.000& 108.941 \end{bmatrix}$$ And I want to find the null space by using gaussian elimination. First of all, I know that the null vector is: (and my goal is to find the eigenvectors […]

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## How i solve the problem “Huaauhahhuahau”?

I have tried to solve this problem (using c++) but my answers are not the same those in the tests. Help, please! All my tests output are “S”. Question: In chats, it is very common among young people and teenagers to use sequences of letters, which often seem random, to reproduce. Some common examples are: […]

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## Bounds on the number of modes in sum of quasi-concve functions

Is there any approach to find a good upper-bound on the number of modes in the sum of several quasi-concave functions? What is the tightest upper-bound? I’m very interested to know whether it is possible to find better bounds by considering some constraints on the functions. For example, in special cases, it can be unimodal. […]