[Tex/LaTex] Draw a line over a node Tikz

drawlinenodestikz-pgf

Can someone help me to draw a red line — like in the photo?
Thank you so much in advanced.

\begin{tikzpicture}
\node[draw,fill=white,ellipse,minimum height=4cm,minimum width=7cm,text width = 5cm,align=center,label=above:\textbf{qStqsfate-spqsface mqsdfodel}] (A)
  {Tranqsdfqsiqsftion \\
  $ \tilde{y}_{t/t-1} = g \big( \tilde{y}_{t-1} ; u_t ; \omega_t \big) $ \\
  $ \downarrow $ \\
  Measurement\\
  $ \tilde{z}_{t/t-1} = f \big( \tilde{y}_{t-1} ; u_t ; \omega_t \big) $  };
\node[xshift=8cm,draw,fill=white,ellipse,minimum height=4cm,minimum width=7cm,text width=5cm,align=center,label=above:\textbf{Estqsdfqsimateqsdfd daqsdfqsdta \; \; \; Empiriqsdfqsdfcal daqsdfqdsfta}] (B)
  {$ \; \; \tilde{y}_{t} \rightarrow \emptyset $ \\
  \vspace{5mm}
  $  \tilde{z}_{t/t-1} \rightarrow z_t $};
\node[xshift=4cm,yshift=-4.5cm,draw,fill=white,ellipse,text width=4cm,align=center,label={[name=kalman]above:\textbf{Kqsdfqalmqsdfqan fqsdfqsdiltqsdfqser}}] (C)
  {$ v_t = y_t - y_{t,t-1} $};
\node[xshift=4cm,yshift=-6.5cm,draw,fill=white,rectangle,minimum height=1.2cm,text width=1.5cm,align=center] (D)
  {$ y_t $};  

\draw [->] (A) to (kalman);
\draw [->] (B) to (kalman);
\draw [->] (C) to (D);

\end{tikzpicture}

Best Answer

Is this what you are looking for?

The node in question already has the name (B), therefore you simply want to draw a line from (B.south) to (B.north). To extend these coordinates slightly use yshift within the coordinates like so: ([yshift=-0.5cm]B.south) and ([yshift=0.5cm]B.north).

\documentclass[border=5mm]{standalone}
\usepackage{amsmath}
\usepackage{tikz}
\usetikzlibrary{shapes.geometric}
\begin{document}
\begin{tikzpicture}
\node[draw,fill=white,ellipse,minimum height=4cm,minimum width=7cm,text width = 5cm,align=center,label=above:\textbf{State-space model}] (A)
  {Transition \\
  $ \tilde{y}_{t/t-1} = g \big( \tilde{y}_{t-1} ; u_t ; \omega_t \big) $ \\
  $ \downarrow $ \\
  Measurement\\
  $ \tilde{z}_{t/t-1} = f \big( \tilde{y}_{t-1} ; u_t ; \omega_t \big) $  };
\node[xshift=8cm,draw,fill=white,ellipse,minimum height=4cm,minimum width=7cm,text width=5cm,align=center,label=above:\textbf{Estimated data \; \; \; Empirical data}] (B)
  {$ \; \; \tilde{y}_{t} \rightarrow \emptyset $ \\
  \vspace{5mm}
  $  \tilde{z}_{t/t-1} \rightarrow z_t $};
\node[xshift=4cm,yshift=-4.5cm,draw,fill=white,ellipse,text width=4cm,align=center,label={[name=kalman]above:\textbf{Kalman filter}}] (C)
  {$ v_t = y_t - y_{t,t-1} $};
\node[xshift=4cm,yshift=-6.5cm,draw,fill=white,rectangle,minimum height=1.2cm,text width=1.5cm,align=center] (D)
  {$ y_t $};  

\draw [red,dashed] ([yshift=-0.5cm]B.south)--([yshift=0.5cm]B.north); %<---- added

\draw [->] (A) to (kalman);
\draw [->] (B) to (kalman);
\draw [->] (C) to (D);

\end{tikzpicture}
\end{document}

Related Solutions

[Tex/LaTex] Top-align text in a TikZ node of given size for single- and multiline case

You could work around this by using two nodes instead of one: The first contains just the text, the second uses the fit library to draw a rectangle of a specified minimum height around the text.

I've written a style called add rectangle that takes an optional height and uses the append after command style to add a second node directly after the text node.

In order to fill the background, you can use the backgrounds library and place the rectangle on the background layer using the pgfonlayer environment.

\documentclass{scrreprt}

\usepackage{tikz}
\usetikzlibrary{positioning,fit,calc,backgrounds}

\usepackage{varwidth}

\tikzset{
    add rectangle/.style={
        alias=tempname,
        append after command={
            ; \begin{pgfonlayer}{background}
        \node [
            fill=yellow,
                draw=yellow!80!black,
                        fit={(tempname) ($(tempname.north)+(0,-#1)$)},
                        inner sep=0pt] {};
        \end{pgfonlayer} \path
        }
    },
    add rectangle/.default=2cm
}

\begin{document}

\begin{tikzpicture}
\node (left) [
    add rectangle=2cm
] {%
\begin{varwidth}{3cm}%
Short%
\end{varwidth}%
};

\node at (left.north east) [name=middle,anchor=north west,add rectangle=2cm] {%
\begin{varwidth}{3cm}%
Somehow a longer text for testing%
\end{varwidth}%
};

\node at (middle.north east) [anchor=north west,add rectangle=2cm] {%
\begin{varwidth}{3cm}%
Somehow a longer text for testing. This is a really long text that will stretch the box vertically.%
\end{varwidth}%
};
\end{tikzpicture}


\end{document}

[Tex/LaTex] Rotate a node but not its content: the case of the ellipse decoration

The source of the difficulty is that ellipses are constructed in a particular way in TikZ. They are paths that start from the x-axis and proceed counter-clockwise around their centre. The vast majority of the time, the exact parametrisation doesn't matter. You appear to have found the one situation where it does!

In the actual question, you only want to be able to mirror the ellipse, and so draw it starting from the negative x-axis (the title of the question suggests a more flexible approach). That's actually not too hard since we can exploit the symmetry of the ellipse. The key is to provide it with a negative x-radius, since then it will start from the negative x-axis (and proceed clockwise, but we could correct for that by negating the y-radius as well). To do this, we interrupt the call from the node shape to the drawing command and flip the sign of the x-radius. The simplest way to do this is to redefine the \pgfpathellipse macro to do the negation and then call the original macro. The following code does this.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{decorations,shapes,decorations.markings}
\makeatletter
\let\origpgfpathellipse=\pgfpathellipse
\def\revpgfpathellipse#1#2#3{%
  #2%
  \pgf@xa=-\pgf@x
  \origpgfpathellipse{#1}{\pgfqpoint{\pgf@xa}{0pt}}{#3}}
\makeatother

\tikzset{
  reversed ellipse/.style={
    ellipse,
    reverse the ellipse%
  },
  reverse the ellipse/.code={
    \let\pgfpathellipse=\revpgfpathellipse
  }
}
\begin{document}
\begin{tikzpicture}
\node[ellipse,
  draw,
  postaction={
    decorate,
    decoration={
      markings,
      mark=at position 1 with {
        \arrow[line width=5pt,blue]{>}
      }
    }
  }
] at (0,0) {hello world};

\node[reversed ellipse,
  draw,
  postaction={
    decorate,
    decoration={
      markings,
      mark=at position 1 with {
        \arrow[line width=5pt,blue]{>}
      }
    }
  }
] at (0,-2) {hello world};
\end{tikzpicture}

\end{document}

Here's the result:

rotated ellipse

(the arrow got clipped, but you can see where it lies)

Best Answer

Related Solutions

[Tex/LaTex] Top-align text in a TikZ node of given size for single- and multiline case

[Tex/LaTex] Rotate a node but not its content: the case of the ellipse decoration

Related Question