Posts

Showing posts from January 19, 2019

Are there cases where fontenc + luatex (or xetex) cause problems?

Image
3 According to the luatex docs, you shouldn't use fontenc with luatex. People swear up and down that fontenc is incompatible, but I haven't been able to find an example where loading the package causes problems. (I'm curious about this because it can be easier to load the same base set of packages for pdftex/luatex/xetex, and add fontspec only when handling the latter two.) I know fontenc is not the right way to deal with fonts in luatex or xelatex, but I'm specifically looking for cases where it's detrimental to load the fontenc package. Do you know of any? fonts xetex luatex share | improve this question asked 4 hours ago ...

Showing a function is Frechet Differentiable?

Image
6 1 $begingroup$ I just started learning the Frechet Derivatives. So I have a function $H:mathbb{R}^{Ntimes n}tomathbb{R}^{Ntimes n}$ , i.e. $U^Tinmathbb{R}^{Ntimes n}$ and $$H(U^T)=GWtimes (F(U))^T+Stimes U^T+C$$ with $G,W,Sin mathbb{R}^{N times N}$ are two matrices of size $Ntimes N$ , $F(cdot)in mathbb{R}^ntomathbb{R}^n $ is a nonlinear function which maps each column vetor of $U$ to the corresponding column vector of $F(U)$ , and $Cinmathbb{R}^{Ntimes n}$ . My question is what property should the nonlinear unknown function $F(cdot)$ satisfy to ensure the function $H(cdot)$ is Frechet differentiable? What does the Frechet derivative matrix looks like? What should I start?Thank you! calculus real-analysis banach-spaces fixed-point-theorems frechet-deriva...