My code about smartdiagram has some problems

Question

My code about smartdiagram has some problems. I would like to ask people who handle Latex, in particular, smartdiagram part.

\begin{frame}{}
    \begin{beamerboxesrounded}[upper=uppercol,lower=lowercol,shadow=true]{Example 2}
        \begin{minipage}[c][3cm]{.5\textwidth}
            \begin{center}
                \smartdiagramset{
                    border color=none,
                    back arrow disabled=true
                }
                \smartdiagram[flow diagram:horizontal]{
                    $X$,
                    Noisy channel,
                    $Y$,
                    $f(\cdot)$,
                    $Z$
                }
            \end{center}
        \end{minipage}

        ...
    \end{beamerboxesrounded}
\end{frame}

I want to draw like the following image:

Moreover, I do not know why the size (width) exceeds the page even though I use minipage environment.

So far, I used to draw image in powerpoint, to save it with pdf extension, to open the pdf file in illustrator program, and re-save the image with eps extension.

Now, I think it's time that I learn to use smartdiagram!!

Thank you for reading my question.

Answer 1

To add text (Y) above the arrow, you can use the additions option of smartdiagram package (see the package documentation for more information).

Concerning your size problem: If you put a something inside a minipage which is larger than said minipage, it will simply stuck out and won't be magically resized. If you want the digram to be smaller, you could try to use \resizebox or similar.

\documentclass{beamer}
\usetheme{Warsaw}

\usepackage{tikz} 
\usepackage{smartdiagram}
\usesmartdiagramlibrary{additions}

\begin{document}
\begin{frame}{}
    \begin{beamerboxesrounded}[upper=uppercol,lower=lowercol,shadow=true]{Example 2}
        \begin{minipage}[c][3cm]{\textwidth}
            \centering
                \smartdiagramset{
                    border color=none,
                    back arrow disabled=true,
                                    additions={
                                      additional item offset=-7mm,
                                      additional item fill opacity=0
                                    }
                }
                \smartdiagramadd[flow diagram:horizontal]{
                    $X$,
                    Noisy channel,
                    $f(\cdot)$,
                    $Z$
                }
                {
                        above right of module2/$Y$~~~,
                }
        \end{minipage}
    \end{beamerboxesrounded}
\end{frame}


\end{document}