[Tex/LaTex] Cyrillic sans font in beamer (LyX)

Question

I am trying to use Cyrillic sans-serif font in a beamer presentation. I make it using LyX 2.0.0.
The code produced by LyX (exported as plain LaTeX) is

%% LyX 2.0.0 created this file.  For more info, see http://www.lyx.org/.
%% Do not edit unless you really know what you are doing.
\documentclass[russian]{beamer}
\usepackage[T1]{fontenc}
\usepackage[koi8-r]{inputenc}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{graphicx}

\makeatletter

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% LyX specific LaTeX commands.
\DeclareRobustCommand{\cyrtext}{%
  \fontencoding{T2A}\selectfont\def\encodingdefault{T2A}}
\DeclareRobustCommand{\textcyr}[1]{\leavevmode{\cyrtext #1}}
\AtBeginDocument{\DeclareFontEncoding{T2A}{}{}}

%% A simple dot to overcome graphicx limitations
\newcommand{\lyxdot}{.}


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Textclass specific LaTeX commands.
 % this default might be overridden by plain title style
 \newcommand\makebeamertitle{\frame{\maketitle}}%
 \AtBeginDocument{
   \let\origtableofcontents=\tableofcontents
   \def\tableofcontents{\@ifnextchar[{\origtableofcontents}{\gobbletableofcontents}}
   \def\gobbletableofcontents#1{\origtableofcontents}
 }
 \long\def\lyxframe#1{\@lyxframe#1\@lyxframestop}%
 \def\@lyxframe{\@ifnextchar<{\@@lyxframe}{\@@lyxframe<*>}}%
 \def\@@lyxframe<#1>{\@ifnextchar[{\@@@lyxframe<#1>}{\@@@lyxframe<#1>[]}}
 \def\@@@lyxframe<#1>[{\@ifnextchar<{\@@@@@lyxframe<#1>[}{\@@@@lyxframe<#1>[<*>][}}
 \def\@@@@@lyxframe<#1>[#2]{\@ifnextchar[{\@@@@lyxframe<#1>[#2]}{\@@@@lyxframe<#1>[#2][]}}
 \long\def\@@@@lyxframe<#1>[#2][#3]#4\@lyxframestop#5\lyxframeend{%
   \frame<#1>[#2][#3]{\frametitle{#4}#5}}
 \def\lyxframeend{} % In case there is a superfluous frame end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% User specified LaTeX commands.
\usepackage{listings}
\usetheme{Warsaw}
%\usepackage{helvet}
% or ...
%\usetheme{Antibes} % tree outline, neat
%\usetheme{JuanLesPins} % like Antibes, with shading
%\usetheme{Bergen}  % outline on side
%\usetheme{Luebeck} % like Warsaw, square sides
%\usetheme{Berkeley}    % interesting left bar outline
%\usetheme{Madrid}  % clean, nice.  7/12 page numbers
%\usetheme{Berlin}  % dots show slide number
%\usetheme{Malmoe}  % OK, plain, unshaded
%\usetheme{Boadilla}    % nice, white bg, no top bar
%\usetheme{Marburg} % nice, outline on right
%\usetheme{boxes}   % ???
%\usetheme{Montpellier} % tree outline on top, plainish white
%\usetheme{Copenhagen}  % like Warsaw
%\usetheme{PaloAlto}    % looks good
%\usetheme{Darmstadt}   % like Warsaw with circle outline
%\usetheme{Pittsburgh}
%\usetheme{default}
%\usetheme{Rochester}   % like boxy, unshaded warsaw
%\usetheme{Dresden} % circle outline on top
%\usetheme{Singapore}   % purple gradient top
%\usetheme{Frankfurt}   % like Warsaw with circle outline on top
%\usetheme{Szeged}
%\usetheme{Goettingen}  % light purple right bar outline
%\usetheme{Warsaw}
%\usetheme{Hannover}    % like Goett with bar on left
%\usetheme{compatibility}
%\usetheme{Ilmenau}

\setbeamercovered{transparent}
% or whatever (possibly just delete it)

%\usecolortheme{seahorse}
%\usecolortheme{rose}

% seems to fix typewriter font in outline header:
\usepackage{ae,aecompl}
\beamertemplatenavigationsymbolsempty
%\pgfdeclareimage[height=1cm]{institution-logo}{hint-logo-mn.jpg}

\makeatother

\usepackage{babel}
\begin{document}

\title[Высокогорные леса]{Историческое использование\\высокогорных лесов}


\subtitle{современное значение\\на государственном и местном уровнях}


\author[S\o{}veig; Наумов]{Robert S\o{}veig, Владимир Наумов}


\institute{Niht}


\date{5 сентября 2012}

\makebeamertitle
%\beamerdefaultoverlayspecification{<+->}


\lyxframeend{}\lyxframe{Robert S\o{}veig}

\begin{center}
\par\end{center}
\begin{block}
{}
\begin{itemize}
\item место работы: 
\item специализация:
\item опыт:
\end{itemize}
\end{block}

\note[item]{Начало доклада}


\note[item]{Теперь я перейду собственно к нашему докладу.}


\lyxframeend{}
\end{document}

The problem is that the font in the output is not sans-serif, although I know that by default beamer uses sans serif font. F.ex. this code:

\documentclass[russian]{beamer}

\usepackage[T2A]{fontenc}
\usepackage[utf8]{inputenc}
\begin{document}
  \begin{frame}
    ПРИВЕТ! Этот текст написан шрифтом без засечек.
  \end{frame}
\end{document}

works flawlessly in plain LaTeX.

I suppose that the problem is in font encoding.

How to force LyX to use correct font encoding, e.g. to produce beamer presentation with sans serif cyrillic fonts?

Answer 1

The first code example is rather messy and, in my opinion, a good demostration why LyX should not be used as it complicates things rather than simplifying them.

In the second code you are forgetting to load babel

\documentclass{beamer}

\usepackage[T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[russian]{babel}

\begin{document}
  \begin{frame}
    ПРИВЕТ! Этот текст написан шрифтом без засечек.
  \end{frame}
\end{document}

In general I prefer to pass the language option to babel rather than to the class (you may have surprises if you want to use multiple languages).

Here's a "more correct" version of the first code (I used utf8 instead of koi8-r). The ae and aecompl packages are obsolete.

\documentclass{beamer}
\usepackage[T1,T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[russian]{babel}

% \usepackage{listings}

\usetheme{Warsaw}

\setbeamercovered{transparent}
\beamertemplatenavigationsymbolsempty

\begin{document}

\title[Высокогорные леса]{Историческое использование\\высокогорных лесов}


\subtitle{современное значение\\на государственном и местном уровнях}


\author[S\o{}veig; Наумов]{Robert S\o{}veig, Владимир Наумов}


\institute{Niht}


\date{5 сентября 2012}

\begin{frame}
\maketitle
\end{frame}

%\beamerdefaultoverlayspecification{<+->}


\begin{frame}
\frametitle{Robert S\o{}veig}

\begin{block}{}
\begin{itemize}
\item место работы: 
\item специализация:
\item опыт:
\end{itemize}
\end{block}

\note[item]{Начало доклада}


\note[item]{Теперь я перейду собственно к нашему докладу.}

\end{frame}
\end{document}