[Tex/LaTex] Vertically align a tikzpicture and forest

foresttikz-pgfvertical alignment

I have this

\documentclass{article}

\usepackage{tikz}
\usepackage{forest}

\usetikzlibrary{positioning}
\usetikzlibrary{automata}

\begin{document}

\begin{tikzpicture}[%
    node distance=0.8cm,
    ->,
    font=\small,
    baseline=(current bounding box.north)
]
\node[state] (s1) {$s_1$};
\node[state] (s2) [above left=of s1] {$s_2$};
\node[state] (s3) [right=of s1] {$s_8$};
\node[state] (s4) [left=of s2] {$s_3$};
\node[state] (s5) [left=of s1] {$s_5$};
\node[state] (s6) [right=of s2] {$s_9$};
\node[state] (s7) [below left=of s3] {$s_{11}$};
\node[state] (s8) [left=of s5] {$s_4$};
\node[state] (s9) [right=of s6] {$s_{10}$};
\node[state] (s10) [left=of s7] {$s_6$};
\node[state] (s11) [left=of s10] {$s_7$};

\path (s1) edge (s2);
\path (s1) edge (s3);
\path (s2) edge (s4);
\path (s2) edge (s5);
\path (s3) edge (s6);
\path (s3) edge (s7);
\path (s4) edge (s8);
\path (s6) edge (s9);
\path (s5) edge (s10);
\path (s5) edge (s11);
\end{tikzpicture}
\qquad
\begin{forest}
for tree={%
    math content,
    state,
    edge={->},
    l sep=0.1cm,
    s sep=0.1cm,
    font=\small
}
[s_1
    [s_2
        [s_3
            [s_4]
            [,phantom]
        ]
        [s_5
            [s_6]
            [s_7]
        ]
    ]
    [s_8
        [s_9
            [,phantom]
            [s_{10}]
        ]
        [s_{11}]
    ]
]
\end{forest}

\end{document}

which produces

I want these two graphs/trees to be equal in height (or at least top-aligned).

I have tried with baseline=(current bounding box.north), but it did not work as expected.

How do I make an arrow between these with some small text above the arrow? Should I put each graph in a node and use \draw (graph1) -- node[above] {text above} (graph2)?

Edit 1

Using baseline=(current bounding box.south), I get

so they are still not aligned vertically.

Seems to be the same as omitting baseline option completely.

Edit 2

The problem is that I cannot fit the two graphs side by side on my page if the tikzpicture has node distance=2cm. So either the forest should be smaller or I should give up on making them the same height, and instead just align them vertically.

Also, it seems placing an tikzpicture side by side with a forest makes a left margin:

My code is

Some text

\begin{center}
\begin{tikzpicture}[%
    node distance=0.9cm,
    ->,
    font=\small,
    framed
]
\node[state] (s1) {$s_1$};
\node[state] (s2) [above left=of s1] {$s_2$};
\node[state] (s3) [right=of s1] {$s_8$};
\node[state] (s4) [left=of s2] {$s_3$};
\node[state] (s5) [left=of s1] {$s_5$};
\node[state] (s6) [right=of s2] {$s_9$};
\node[state] (s7) [below left=of s3] {$s_{11}$};
\node[state] (s8) [left=of s5] {$s_4$};
\node[state] (s9) [right=of s6] {$s_{10}$};
\node[state] (s10) [left=of s7] {$s_6$};
\node[state] (s11) [left=of s10] {$s_7$};

\path (s1) edge (s2);
\path (s1) edge (s3);
\path (s2) edge (s4);
\path (s2) edge (s5);
\path (s3) edge (s6);
\path (s3) edge (s7);
\path (s4) edge (s8);
\path (s6) edge (s9);
\path (s5) edge (s10);
\path (s5) edge (s11);
\end{tikzpicture}
\hfill
\begin{forest}
for tree={%
    math content,
    state,
    edge={->},
    l sep=0.1cm,
    s sep=0.1cm,
    font=\small,
}
[s_1
    [s_2
        [s_3
            [s_4]
            [,phantom]
        ]
        [s_5
            [s_6]
            [s_7]
        ]
    ]
    [s_8
        [s_9
            [,phantom]
            [s_{10}]
        ]
        [s_{11}]
    ]
]
\end{forest}
\end{center}

If I remove the forest and does not center it, it it left aligned with Some text just above it.

Best Answer

To top-align the trees, you need to set an appropriate (north) baseline for both trees. You have already done that for the tikzpicture tree. For the forest tree, you achieve this by adding options baseline and anchor=north to the root node (either in the root node specification, or in the preamble).

You need to specify anchor=north as baseline sets the node's anchor as the baseline for the picture (manual section 3.7.5).

The full code:

\documentclass{article}

\usepackage{tikz}
\usepackage{forest}

\usetikzlibrary{positioning}
\usetikzlibrary{automata}

\begin{document}

\begin{tikzpicture}[%
    node distance=0.8cm,
    ->,
    font=\small,
    baseline=(current bounding box.north)
]
\node[state] (s1) {$s_1$};
\node[state] (s2) [above left=of s1] {$s_2$};
\node[state] (s3) [right=of s1] {$s_8$};
\node[state] (s4) [left=of s2] {$s_3$};
\node[state] (s5) [left=of s1] {$s_5$};
\node[state] (s6) [right=of s2] {$s_9$};
\node[state] (s7) [below left=of s3] {$s_{11}$};
\node[state] (s8) [left=of s5] {$s_4$};
\node[state] (s9) [right=of s6] {$s_{10}$};
\node[state] (s10) [left=of s7] {$s_6$};
\node[state] (s11) [left=of s10] {$s_7$};

\path (s1) edge (s2);
\path (s1) edge (s3);
\path (s2) edge (s4);
\path (s2) edge (s5);
\path (s3) edge (s6);
\path (s3) edge (s7);
\path (s4) edge (s8);
\path (s6) edge (s9);
\path (s5) edge (s10);
\path (s5) edge (s11);
\end{tikzpicture}
\qquad
\begin{forest}
  baseline,anchor=north,
for tree={%
    math content,
    state,
    edge={->},
    l sep=0.1cm,
    s sep=0.1cm,
    font=\small
}
[s_1
    [s_2
        [s_3
            [s_4]
            [,phantom]
        ]
        [s_5
            [s_6]
            [s_7]
        ]
    ]
    [s_8
        [s_9
            [,phantom]
            [s_{10}]
        ]
        [s_{11}]
    ]
]
\end{forest}

\end{document}

To get the trees of the same height, first measure the height of the tikzpicture tree (https://tex.stackexchange.com/a/137367/16819) and then use this information to compute (within forest) the needed level separation.

This is the code, explanation below. Note that the node distance in the left tree needed to be increased, otherwise that tree was just not high enough.

\documentclass{article}

\usepackage{fullpage}
\usepackage{tikz}
\usepackage{forest}

\usetikzlibrary{positioning}
\usetikzlibrary{automata}
\usetikzlibrary{backgrounds}

\newlength{\mywidth}
\newlength{\myheight}

% computes width and height of tikzpicture
\makeatletter
\newcommand{\pgfsize}[2]{ % #1 = width, #2 = height
 \pgfextractx{\@tempdima}{\pgfpointdiff{\pgfpointanchor{current bounding box}{south west}}
 {\pgfpointanchor{current bounding box}{north east}}}
 \global#1=\@tempdima
 \pgfextracty{\@tempdima}{\pgfpointdiff{\pgfpointanchor{current bounding box}{south west}}
 {\pgfpointanchor{current bounding box}{north east}}}
 \global#2=\@tempdima
 %\draw (current bounding box.north east) -- (current bounding box.south west);
}
\makeatother



\begin{document}

\begin{center}
\begin{tikzpicture}[%
    node distance=1.5cm,
    ->,
    font=\small,
    %framed
]
\node[state] (s1) {$s_1$};
\node[state] (s2) [above left=of s1] {$s_2$};
\node[state] (s3) [right=of s1] {$s_8$};
\node[state] (s4) [left=of s2] {$s_3$};
\node[state] (s5) [left=of s1] {$s_5$};
\node[state] (s6) [right=of s2] {$s_9$};
\node[state] (s7) [below left=of s3] {$s_{11}$};
\node[state] (s8) [left=of s5] {$s_4$};
\node[state] (s9) [right=of s6] {$s_{10}$};
\node[state] (s10) [left=of s7] {$s_6$};
\node[state] (s11) [left=of s10] {$s_7$};

\path (s1) edge (s2);
\path (s1) edge (s3);
\path (s2) edge (s4);
\path (s2) edge (s5);
\path (s3) edge (s6);
\path (s3) edge (s7);
\path (s4) edge (s8);
\path (s6) edge (s9);
\path (s5) edge (s10);
\path (s5) edge (s11);
\pgfsize{\mywidth}{\myheight}
\end{tikzpicture}
\hfill
\begin{forest}
for tree={%
    math content,
    state,
    edge={->},
    font=\small,
},
before packing={%
  tempcounta/.max={level}{tree}, % count the levels in the tree
  tempdima=max_y()-min_y(), % node height (assuming it's the same for all nodes)
  tempdimb=((\myheight-(tempcounta()+1)*tempdima())/tempcounta()),
  if tempdimb<={0pt}{TeX={\errmessage{The left picture is not high enough!}}}{},
  for tree={l=0,l sep=tempdimb},
}
[s_1
    [s_2
        [s_3
            [s_4]
            [,phantom]
        ]
        [s_5
            [s_6]
            [s_7]
        ]
    ]
    [s_8
        [s_9
            [,phantom]
            [s_{10}]
        ]
        [s_{11}]
    ]
]
\end{forest}
\end{center}

\end{document}

So:

The desired height is stored in \myheight.
Aggregate function max (manual section 3.14) gets the deepest level.
Using min_x, max_x, min_y, max_y, one can obtain the dimensions of a node. Note that this must be used after the typesetting nodes stage (see manual section 3.4.1). And as the desired level distance must be set before packing, the relevant code goes into temporal propagator before packing.
Some simple math to compute the desired distance between the parent and child node
The result is stored into l sep (not l!). This must be so because we have computed the distance between the southmost point of the parent and the northmost point of the child. (Setting l would set the distance between the parent's and the child's node anchors.) l must be set to 0pt to get rid of the default minimum and let the l sep determine the distance on its own.

An alternative way to set the baseline of the tree is to use tikz's baseline directly. This can be achieved by modifying (appending to) macro stored by begin draw (manual section 3.4.3). To set the baseline to the center of the entire tree, write

begin draw/.append code={[baseline=(current bounding box.center)]},

Note that for historic reasons, begin draw is not a forest toks register, but must be set using pgfkeys handler from the .code family, see PGF manual section 82.4.3. :-(

Related Solutions

[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)

[Tex/LaTex] How to define the default vertical distance between nodes

I don't really get the question so I hope this is what you wanted. If you include a full document (such that we copy paste and see the problem on our systems) things are much more easier.

Here, you can change the default setting within a scope but your block style had a node distance which was resetting every time it is issued. I've made it 2mm such that we can see the difference easier.

\documentclass[tikz]{standalone}
\usetikzlibrary{arrows,shapes.geometric,positioning}

\begin{document}
\begin{tikzpicture}[decision/.style={diamond, draw, text width=4.5em, text badly centered, node distance=3.5cm, inner sep=0pt},
                    block/.style   ={rectangle, draw, text width=6em, text centered, rounded corners, minimum height=4em, minimum height=2em},
                    cloud/.style   ={draw, ellipse, minimum height=2em},
                    line/.style    ={draw,-latex'},
                    node distance = 1cm, 
                    auto]
    \node [block] (1st) {1st};
    \node [block, right= of 1st]  (2nd1) {2nd1};
\begin{scope}[node distance=2mm and 10mm]%Here we change it for everything inside this scope
    \node [block, above= of 2nd1] (2nd2) {2nd2};
    \node [block, below= of 2nd1] (2nd3) {2nd3};
    \node [block, right= of 2nd1] (3rd1) {3rd1};
    \node [block, above= of 3rd1] (3rd2) {3rd2};
    \node [block, above= of 3rd2] (3rd3) {3rd3};
\end{scope}
    \node [block, below= of 3rd1] (3rd4) {3rd4};
    \node [block, below= of 3rd4] (3rd5) {3rd5};

    \path [line] (1st) -- (2nd1);
    \path [line] (2nd1) -- (2nd2);
    \path [line] (2nd1) -- (2nd3);
    \path [line] (2nd2) -- (3rd3);
    \path [line] (2nd1) -- (3rd1);
    \path [line] (1st) -- (2nd1);
\end{tikzpicture}
\end{document}

enter image description here