[Tex/LaTex] tikz put text under rectangle

tikz-pgf

I want to draw a figure like this

But what I get now is this

There are two problems: (1) the red and blue rectangle are not same height, (2) the label stack and buffer are not aligned center. I'm new to tikz, can anyone show some directions that I can improve the figure?

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows}
\usetikzlibrary{calc}

\begin{document}

\begin{tikzpicture}[->,>=stealth',node distance=1cm]
    \draw [help lines] (0,0) grid (6,2);
    \node [text] (1) {I};
    \node [text] (2) [right of=1] {booked};
    \node [text] (3) [right of=2] {a};
    \node [text] (4) [right of=3] {ticket};
    \node [text] (5) [right of=4] {to};
    \node [text] (6) [right of=5] {China};

    \path (2) edge[bend right=70] node [above]{nsubj} (1);
    \path (2) edge[bend left=90] node [above]{dobj} (4);
    \path (4) edge[bend right=70] node [left]{det} (3);
    \path (4) edge[bend left=70] node [above]{prep} (5);
    \path (5) edge[bend left=70] node [above]{pobj} (6);

    \draw [red,thick,minimum height=2cm] (stack) ($(1.north west)$) rectangle ($(2.south east)$);
    \node [text,align=center] [below=stack] {stack};

    \draw [blue,thick,minimum height=2cm] (buffer) ($(3.north west)$) rectangle ($(6.south east)$);
    \node [text,align=center] [below=buffer] {buffer};
\end{tikzpicture}

\end{document}

Best Answer

Do you like to obtain something like this?

I significantly change your MWE:

introduce new libraries: chains, fit and quotes,
delete calc, since it is not used
for red and blue rectangles is used node, which fit txt nodes
define new styles: txt (text is used name in TikZ and had not to be used for locally defined styles) and redefine edge styles
for edge labels is used library quotes
text below red and blue rectangles are labels to respective nodes

Complete MWE:

\documentclass[tikz,
               border=3mm]{standalone}
\usetikzlibrary{arrows, chains, fit, quotes}

\begin{document}
    \begin{tikzpicture}[
node distance = 10mm,
  start chain = A going right,
   txt/.style = {text height=2ex, text depth=0.25ex,
                 on chain},
every edge/.append style = {draw, -stealth'}
                        ]
\draw [help lines] (-1,-1) grid (10,2);
\node [txt] {I};     % nodes are in the chain
\node [txt] {booked};
\node [txt] {a};
\node [txt] {ticket};
\node [txt] {to};
\node [txt] {China};
%
\node (f1)  [draw=red, inner sep=0pt, % red rectangle
             label=below:stack, % "node below rectangle done by node label
             fit=(A-1) (A-2)] {};
\node (f2)  [draw=blue,inner sep=0pt, % blue rectangle
             label=below:buffer,% "node below rectangle done by node label
              fit=(A-3) (A-6)] {};
%
\path   (A-2) edge[bend right=70, "nsubj" '] (A-1)
        (A-2) edge[bend  left=90, "dobj"   ] (A-4)
        (A-4) edge[bend right=70, "det"   '] (A-3)
        (A-4) edge[bend  left=70, "prep"   ] (A-5)
        (A-5) edge[bend  left=70, "pobj"   ] (A-6);
    \end{tikzpicture}
\end{document}

Related Solutions

[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

[Tex/LaTex] Adjusting edge alignment and positioning of fitted node

This is done by setting the width of the first node, and then fitting the other two nodes to the previous nodes, using the fit library.
Same as #1.
Solved with #1.
This depends on what you want to do. If you only want two short nodes inside of the yellow, you can add two more nodes anchored there. But it depends on what you want to do

Output

Code

\documentclass[margin=10pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{positioning,fit}

\tikzset{
    every node/.style={draw, rectangle, align=center, text width=3cm, inner sep=0, thick, outer sep=0}
}

\begin{document}
\begin{tikzpicture}[node distance=5mm]
\node[fill=green!40, minimum height=2cm, minimum width=5cm, text width=3cm] (one) {This is\\block top left};
\node[fill=red!40,  fit={(one.west) (one.east)}, minimum height=1cm, anchor=north west, below =of one] (two) {block bottom left};
\node[fill=yellow, fit={(one)(two)},right =of two.south east, anchor=south west] (three) {This is\\block right};

\end{tikzpicture}
\end{document}