[Tex/LaTex] Why might \sin and \cos be italicized in the output

amsmathitalicmath-modeunicode-math

Introduction

I know that \sin and \cos are supposed to produce non-italicized (operator) output when in math mode.

Oddly, these macros are producing italicized output, as if I had typed sin or cos—that is, without the backslash.

My Question

The unicode-math package seems to be at fault here. What's going on, and why would it override the trig commands?

Minimum Working Example (MWE)

I've got a rather large document, so my MWE includes a few packages that may seem unusual for this MWE. I've stripped it down quite a bit to get what is given below.

Here's the preamble:

\documentclass[10pt,letterpaper,notitlepage,final]{report}
%%##$#% !BIB TS-program = biber
% The above line is REQUIRED -- see http://tex.stackexchange.com/questions/38348/in-texshop-is-there-a-directive-to-select-biber-or-bibtex-on-a-per-document-bas

\usepackage[T1]{fontenc}
\usepackage{lmodern} % better font -- REQUIRED for special unicode characters
\usepackage{unicode-math}  % for \oiint command (also loads fontspec)
\usepackage{amsmath}  % conflicts with \oiint
\usepackage[arrow]{hhtensor}  % for vector and tensor notation
\usepackage{graphicx}   % Allows me to include figures


\begin{document}

Here's an equation:
\begin{equation}
    1 = \cos^2 \theta + \sin^2 \theta
\end{equation}

\end{document}

Best Answer

unicode-math should be loaded after all font-packages (well, packages, that load fonts as well, like amsmath etc.) are loaded, to provide the corresponding changes.

The unicode-math package states (see section 3 Getting started):

Load unicode-math as a regular LATEX package. It should be loaded after any other maths or font-related package in case it needs to overwrite their definitions

\documentclass[10pt,letterpaper,notitlepage,final]{report}
%%##$#% !BIB TS-program = biber
% The above line is REQUIRED -- see http://tex.stackexchange.com/questions/38348/in-texshop-is-there-a-directive-to-select-biber-or-bibtex-on-a-per-document-bas


\usepackage{amsmath}  % conflicts with \oiint
\usepackage[arrow]{hhtensor}  % for vector and tensor notation
\usepackage{graphicx}   % Allows me to include figures
\usepackage{unicode-math}  % for \oiint command (also loads fontspec)

\begin{document}
Here's an equation:
\begin{equation}
    1 = \cos^2 \theta + \sin^2 \theta
\end{equation}

\end{document}

Related Solutions

[Tex/LaTex] How to use AMS Euler font in functions such as \sin and \cos

Euler is not really compatible with Computer Modern, it's better with Palatino, in my opinion.

As a rule, the operator names such as sine, cosine and logarithm are typeset with the normal (upright) text font, in order not to be confused with products of quantities: “sin” does not mean the product “s by i by n”.

\documentclass[border=2]{standalone}

\usepackage{newpxtext,newpxmath}
\usepackage{eulervm}

\begin{document}

$e^{x+iy} = e^x(\cos y + i\sin y)$

\end{document}

Note that eulervm is to be preferred to the outdated euler package.

You can surely see that the appearance is better.

You can change the font for operator names to be the same as for variables:

\documentclass[border=2]{standalone}

\usepackage{newpxtext,newpxmath}
\usepackage{eulervm}

\makeatletter
\renewcommand{\operator@font}{\mathgroup\symletters}
\makeatother

\begin{document}

$e^{x+iy} = e^x(\cos y + i\sin y)$

\end{document}

I recommend not doing it.

[Tex/LaTex] algorithm2e – why are some of the texts are italicized and some are not

There are a number of things wrong with your current approach/usage of algorithm2e. In no particular order:

Use \; as line endings, not \\. If you don't want the semi-colons to be printed, add \DontPrintSemicolon to your preamble.
Surround your math content by $...$.
Define \argmin as an operator.
For consistency, define commands that do stuff. For example, formatting a "variable" in your pseudocode, one could define
```
\newcommand{\var}{\texttt}
```
and use \var for every variable.
The first argument of \ForEach (and other conditional clauses in algorithm2e) is set using \itshape. If you want it to not be italics, then set it using {\upshape ...} or \textup{...}.
Use mathptmx rather than the obsolete times.

\documentclass{article}

\usepackage{mathptmx,amsmath}
\usepackage[linesnumbered,boxed]{algorithm2e}
\DontPrintSemicolon

\DeclareMathOperator{\argmin}{argmin}% https://tex.stackexchange.com/q/5223/5764

\newcommand{\var}{\texttt}

\begin{document}

 \begin{algorithm}
  \SetKwInOut{Input}{Input}
  \SetKwInOut{Output}{Output}
  \Input{a graph $G = (V,E)$}
  \Output{a hierarchical tree}  
  \BlankLine
  Initialize edge weights\;
  \ForEach{ \textup{vertex} $V_i \subset V$ }
  { 
    $j \leftarrow \argmin_k (\var{cost}(V_i, V_k))$ where $k \subset \text{neighbours of $i$}$\;
    $E_{ij} \leftarrow E_{ij} + 1$\;
  }
  \BlankLine
  \ForEach{ \textup{edge} $E_{ij} \subset E$ }
  { 
    $E_{ij} \leftarrow \argmin (E_{ij} \text{.weight})$ where $j \subset N$\;
    $E_{ij} \leftarrow E_{ij} + 1$\;
  }
\end{algorithm}

\end{document}

As a side-note, I find the use of

$E_{ij} \leftarrow E_{ij} + 1$\;

superfluous, as the pseudocode construction already indicates that you're going through each E_{ij}. Moreover, what does E_{ij} + 1 refer to?