# Tagged Questions

**0**

votes

**0**answers

69 views

### Bounding the norm of the Dirichlet kernel as a matrix function

I asked the following there also, but I am beginning to think it would be more appropriate here.
Consider the Dirichlet kerel:
$f(x) = 1+2\sum_{k=1}^{N}\cos(kx)$.
Now, given a diagonalizable real ...

**9**

votes

**1**answer

201 views

### Determinant of $V^* V$ where $V$ is rectangular Vandermonde matrix with nodes on unit circle

Let $z_{1},\dots,z_{k}$
be distinct complex numbers with $\left|z_{j}\right|=1,\;j=1,\dots,k$. For any natural $N\geqslant k$
consider the rectangular Vandermonde matrix
$$
V_{N}=\begin{pmatrix}1 ...

**0**

votes

**1**answer

68 views

### The influence of eigendecomposition on the periodicity of a (rank 2) Hermitian matrix (of functions)

Let $\boldsymbol{R}(u,v);~u,v\in\mathbb{R}$ be a Hermitian matrix (of Hermitian functions) with entries
\begin{equation}
r_{ij}(u,v) = 1 + Ae^{-2\pi i \phi_{ij}(ul_0 + vm_0)}; ...

**9**

votes

**5**answers

644 views

### Eigenvalues of a sum of Hermitian positive definite circulant matrix and a positive diagonal matrix

Suppose I have a real $n\times n$ matrix $\mathbf{C}$ that is Hermitian, positive-definite, and circulant. We know that its eigenvalues $\{\lambda_0,\ldots,\lambda_{n-1}\}$ are extraordinarily nice ...

**4**

votes

**2**answers

2k views

### How does the Laplace Transform work for circuit analysis? [closed]

I would like to understand how signals transformed from the time domain to the frequency domain for algebraic manipulation, can be transformed back to give solutions in the time domain. Knowing how to ...

**2**

votes

**1**answer

110 views

### uniform bit generator

I'm trying this question for days but no luck, if someone can give me a lead or an article that solves this.. it would be great:
A uniform bit generator is a function $f:\{0,1\}^n \times \{0,1\}^n ...

**14**

votes

**1**answer

2k views

### Fast Fourier Transform for Graph Laplacian?

In the case of a regularly-sampled scalar-valued signal $f$ on the real line, we can construct a discrete linear operator $A$ such that $A(f)$ approximates $\partial^2 f / \partial x^2$. One way to ...

**1**

vote

**2**answers

268 views

### Using Wavelet Transforms to Approximate Matrices

It's a long time since I worked on this kind of problem, so please bear with me.
I have an approximate inverse matrix that I'm using as a preconditioner to solve the conjugate gradient method. ...