[Tex/LaTex] TikZ: how to draw a diamond child

tikz-pgfworkflow

I need to draw an "easy" flowchart. I would do that, using the child statement. I've used (as example) an example found here. I've modified it and this is the code:

    \documentclass{article}
\usepackage{tikz}
\usetikzlibrary{trees}

\usepackage[active,tightpage]{preview}% just for showing image
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{5pt}%
%-------definisce stile dei nodi---------------
\tikzstyle{startstop} = [rectangle, rounded corners, minimum width=5cm, minimum height=1cm,text centered, draw=black, fill=red!50]

\tikzstyle{io} = [trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=blue!30]

\tikzstyle{process} = [rectangle, minimum width=3cm, minimum height=1cm, text centered, text width=3cm, draw=black, fill=orange!30]

\tikzstyle{decision} = [diamond, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=green!30]

\tikzstyle{arrow} = [thick,->,>=stealth]
%--------------------------------------

    \begin{document}
\begin{tikzpicture}[
thick,
every node/.style = {
      text width = 5em,
      top color = blue!60,
      bottom color = blue!60,
      rectangle,
      font = \sffamily,
      text=white
                    },
sibling distance = 7em,
edge from parent fork down                  
  ]
\node[text width=10em] (T0) {test0}
    child {node (T1) {test1}
    %child {node[ellipse,draw] (right node) {right}};
        child {node[diamond, red] (T4) {test4}
            child {node (T5) {test5}}
        }}
    child {node (T2) {test2}}
       ;
\end{tikzpicture}
    \end{document}

But the "diamond" icon doesn't work. I've also tried to insert the "decision" style that I've created

 \tikzstyle{decision} = [diamond, minimum width=3cm, minimum
 height=1cm, text centered, draw=black, fill=green!30]

and neither this nor "diamond" works.

How can I draw a "diamond" (because I need to draw a decision Icon)?

Best Answer

As Claudio Fiandrino said, you need to load the shapes (or shapes.geometric) tikzlibrary, too, in order to make diamond work.

When I tried your code, the setting every node./style={...} gave some problems, because it was overriding the decisionstyle (and all the other styles):

Since you have defined a style for each node, I'd suggest you to use them:

This is the code:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{trees,shapes.geometric}

\usepackage[active,tightpage]{preview}% just for showing image
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{5pt}%
%-------definisce stile dei nodi---------------
\tikzstyle{startstop} = [rectangle, rounded corners, minimum width=5cm, minimum height=1cm,text centered, draw=black, fill=red!50]

\tikzstyle{io} = [trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=2cm, minimum height=1cm, text centered, draw=black, fill=blue!30]

\tikzstyle{process} = [rectangle, minimum width=2cm, minimum height=1cm, text centered, text width=2cm, draw=black, fill=orange!30]

\tikzstyle{decision} = [diamond, minimum width=2cm, minimum height=1cm, text centered, draw=black, fill=green!30]

\tikzstyle{arrow} = [thick,->,>=stealth]
%--------------------------------------

\begin{document}
\begin{tikzpicture}[
thick,
every node/.style = {
      font = \sffamily,
      text=white
                    },
sibling distance = 7em,
edge from parent fork down                  
  ]
\node[startstop,text width=10em] (T0) {test0}
    child {node[process] (T1) {test1}
    %child {node[ellipse,draw] (right node) {right}};
        child {node[decision,text=red] (T4) {test4}
            child {node[process] (T5) {test5}}
        }}
    child {node[process] (T2) {test2}}
       ;
\end{tikzpicture}
\end{document}

EDIT: some more suggestions, thanks to Claudio Fiandrino's comment:

In order to show only the image the standalone class is better, and you won't need this code:

\usepackage[active,tightpage]{preview}% just for showing image
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{5pt}%

but only \documentclass{standalone}.

Usually it's better to use \tikset{...} than \tikzstyle{...} to define the style of a node. For more information, you can read the answer linked by Claudio Fiandrino (Should \tikzset or \tikzstyle be used to define TikZ styles?).

The new improved code, that produces the same output, is the following:

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{trees,shapes.geometric}

%-------definisce stile dei nodi---------------
\tikzset{%
        startstop/.style={rectangle, rounded corners, minimum width=5cm, minimum height=1cm,text centered, draw=black, fill=red!50},
        io/.style={trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=blue!30},
        process/.style={rectangle, minimum width=2cm, minimum height=1cm, text centered, text width=2cm, draw=black, fill=orange!30},
        decision/.style={diamond, minimum width=2cm, minimum height=1cm, text centered, draw=black, fill=green!30},
        arrow/.style={thick,->,>=stealth},
        every node/.style={font = \sffamily,text=white}
}

%--------------------------------------

\begin{document}
\begin{tikzpicture}[
    thick,
    sibling distance = 7em,
    edge from parent fork down                  
  ]
\node[startstop,text width=10em] (T0) {test0}
    child {node[process] (T1) {test1}
    %child {node[ellipse,draw] (right node) {right}};
        child {node[decision,text=red] (T4) {test4}
            child {node[process] (T5) {test5}}
        }}
    child {node[process] (T2) {test2}}
       ;
\end{tikzpicture}
\end{document}

EDIT 2: After some trial and error, I obtained this result:

I defined three diffent styles for the edge between the diamond and its childs:

\tikzset{%
        MyEdgeA/.style={edge from parent path={(\tikzparentnode.west) -| (\tikzchildnode.north)}},
        MyEdgeB/.style={edge from parent path={(\tikzparentnode.south) -| (\tikzchildnode.north)}},
        MyEdgeC/.style={edge from parent path={(\tikzparentnode.east) -| (\tikzchildnode.north)}}
}

You can set the type of edge you want giving it as a child option:

child[MyEdgeA]{...}

Moreover, I changed the distance between the diamond and the subsequent nodes with:

level 3/.style={level distance=5em}

The complete code is:

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{trees,shapes.geometric}

%-------definisce stile dei nodi---------------
\tikzset{%
        startstop/.style={rectangle, rounded corners, minimum width=5cm, minimum height=1cm,text centered, draw=black, fill=red!50},
        io/.style={trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=blue!30},
        process/.style={rectangle, minimum width=2cm, minimum height=1cm, text centered, text width=2cm, draw=black, fill=orange!30},
        decision/.style={diamond, minimum width=2cm, minimum height=1cm, text centered, draw=black, fill=green!30},
        arrow/.style={thick,->,>=stealth},
        every node/.style={font=\sffamily,text=white}
}

\tikzset{%
        MyEdgeA/.style={edge from parent path={(\tikzparentnode.west) -| (\tikzchildnode.north)}},
        MyEdgeB/.style={edge from parent path={(\tikzparentnode.south) -| (\tikzchildnode.north)}},
        MyEdgeC/.style={edge from parent path={(\tikzparentnode.east) -| (\tikzchildnode.north)}}
}
%--------------------------------------

\begin{document}
\begin{tikzpicture}[
    thick,
    sibling distance = 7em,
    edge from parent fork down,
    level 3/.style={level distance=5em}
  ]
\node[startstop,text width=10em] (T0) {test0}
    child {node[process] (T1) {test1}
    %child {node[ellipse,draw] (right node) {right}};
        child {node[decision,text=red] (T4) {test4}
            child[MyEdgeA] {node[process] (T5) {test5}
                edge from parent
                node[pos=0.5,above,text=black] {No}}
            child[MyEdgeB] {node[process] (T6) {test6}
                edge from parent
                node[pos=0.7,right,text=black] {bla bla..}}
            child[MyEdgeC] {node[process] (T7) {test7}
                edge from parent
                node[pos=0.5,above,text=black] {Yes}}
        }}
    child {node[process] (T2) {test2}}
       ;
\end{tikzpicture}
\end{document}

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

Best Answer

Related Solutions

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

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

Related Question