Latex Flow Diagrams using Tikz

The flowchart is a method to outline an algorithm. It is widely used for effectively representing the information. It is a visual representation of steps and the decision, which are required to perform the specific process.

The process can be viewed quickly, and the steps can be followed from the beginning to the end. The different shapes used in the diagram or chart are termed as flowchart symbols.

Similarly, in latex, you can insert any flow chart or diagram anywhere using some commands.

Let-s understand it with an example. The topic here will give you the idea to create flow diagrams. You can create your type and style for the diagram.

The first diagram will give you the basic idea of a simple flow diagram, while the second example will be a complicated flow diagram.

1. The code for the first example is given below:

\documentclass{article}

\usepackage{tikz} % the tikz package
\usetikzlibrary{shapes.geometric,arrows} % to implement the corresponding shapes and arrows, these are used.
\begin{document}

% the commands given below are used to define the styles for particular blocks. You can modify the dimensions, texture, etc. according to the requirements.
 
\tikzstyle{block} = [rectangle, draw, fill=yellow!50, 
    text width=4.5em, text centered, rounded corners, minimum height=4em] % the width signifies the width of the box. You can change the width accordingly, while the height will be adjusted according to the text.
    % it signifies that for the Block section, the Rectangle shape will be used. The color or shape can be modified.
    % here, distance is the distance between the corresponding block
\tikzstyle{line} = [draw, -latex']
\tikzstyle{cloud} = [draw, ellipse,text width= 2.9em, fill=red!50, node distance=2cm, minimum height=3em]
% the greater the value of the larger, the darker the color.
% the shapes that are determined above with the width, and the color will only be used further. The shapes not declared here, will not be recognized by the Latex.
 \tikzstyle{io} = [trapezium, draw, trapezium right angle=110, rounded corners, fill=red!20, node distance=1.9cm, minimum height=2.9em]  
 % the draw command here is used to draw the boundary of mentioned shape.
% you can add more parameters to the tikzstyle according to the requirements.
\begin{tikzpicture}[node distance = 1.8cm, auto] % the command node distance is important as it determines the space or the length of the arrow between different blocks.
    % the command given below are the place of nodes
    \node [cloud] (init) {Start};
    \node [io, below of= init](ReadA){Read A};
    \node [io, below of= ReadA](ReadB){Read B};
    \node [block, below of = ReadB](Sum){Sum = A+B};
    \node [block, below of = Sum](P){Print Sum};
    \node [cloud, below of = P](Out){End};
    \path [line] (init) -- (ReadA); 
    \path [line] (ReadA) -- (ReadB); 
    \path [line] (ReadB) -- (Sum); 
    \path [line] (Sum) -- (P); 
    \path [line] (P) -- (Out); 
    
\end{tikzpicture}
\end{document}

Output:

$Latex Flow Diagrams using Tikz$

2. The code for the second example is given below:

\documentclass{article}

\usepackage{tikz} % the tikz package
\usetikzlibrary{shapes.geometric, arrows} 
\begin{document}

\tikzstyle{decision} = [diamond, draw, fill=orange!80, 
    text width=5.0em, text centered, node distance=3.1cm,] 
    \tikzstyle{document} = [rectangle, draw, fill=blue!30, 
    text width=4.7em, text centered, node distance=2.5cm,] 
   \tikzstyle{block1} = [rectangle, draw, fill=green!50,  %here, we have chosen another block for the different color
    text width=4.5em, text centered, rounded corners, node distance= 3cm, minimum height=3em] % you can create as many different shapes to make your diagram more creative and attractive, depending on the requirements
\tikzstyle{block} = [rectangle, draw, fill=yellow!50, 
    text width=4.5em, text centered, rounded corners, node distance=2.25cm, minimum height=4em]
\tikzstyle{line} = [draw, -latex']
\tikzstyle{cloud} = [draw, ellipse,text width= 2.9em, fill=red!50, node distance=2cm, minimum height=3em]

\tikzstyle{ioi} = [trapezium, draw, trapezium right angle=120,rounded corners, fill=blue!60, node distance=2.8cm, minimum height=2.7em]
 \tikzstyle{io} = [trapezium, draw, trapezium right angle=110,rounded corners, fill=red!20, node distance=1.9cm, minimum height=2.9em]   % the draw command here is used to draw the boundary of mentioned shape.
\begin{tikzpicture}[node distance = 1.8cm, auto] % the command node distance is important as it determines the space or the length of the arrow between different blocks.
    % the command given below are the place of nodes
    \node [cloud] (init) {Start};
    \node [io, below of=init](A){Step A};
    \node [io, below of=A](B){Step B};
    \node [block, below of = B](C){Step C};
    \node [block, below of = C](D){Step D};
    \node [decision, below of = D](E){Step E};
    \node [document, below of = E](F){Step F};
    \node [cloud, below of = F](G){Step G};
    \node [block1, right of = D](H){Step H};
    \node [ioi, below of = H](I){Step I};
    \node [decision, left of = D](J){Step J};
    \node [ioi, below of = J](K){Step K};
    \path [line] (init) -- (A); 
    \path [line] (A) -- (B); 
    \path [line] (B) -- (C); 
    \path [line] (C) -- (D); 
    \path [line] (D) -- (E); 
    \path [line] (E) -- (F); 
    \path [line] (F) -- (G); 
    \path [line] (D) -- (H); 
    \path [line] (H) -- (I); 
    \path [line] (I) |- (G.east); % |- is used for making the rectangular arrow
    \path [line] (C) |- (J.north); % to position the arrow, you can use north, south, east, and west directions
    \path [line] (J) -- (K); 
    \path [line] (K) |- (F.west); 
    \path [line, dashed] (H) |- (init.east); % the dashed command is used to create the dashed line
    
\end{tikzpicture}
\end{document}

Output: