TikZ

📐 Introduction to TikZ

TikZ is a powerful package for creating high-quality vector graphics directly in LaTeX documents. It is widely used in scientific documents for plotting diagrams, geometric figures, biological pathways, and more.

✅ Key Features

• Seamless integration with LaTeX
• Outputs publication-quality vector graphics (PDF)
• Supports coordinates, layers, and mathematical operations

🧱 Basic TikZ Structure

\documentclass{article}
\usepackage{tikz}
\begin{document}
 
\begin{tikzpicture}
  \draw (0,0) -- (2,0) -- (1,1.5) -- cycle;  % Draws a triangle
\end{tikzpicture}
 
\end{document}

🔧 Common Commands

Command	Description
\draw	Draws lines and paths
\node	Places labeled nodes or text
\fill	Fills shapes with color
--	Straight line between points
cycle	Closes the shape back to the starting point

✏️ Example: Labeled Graph

\begin{tikzpicture}
  \node[circle,draw] (A) at (0,0) {A};
  \node[circle,draw] (B) at (2,0) {B};
  \draw[->] (A) -- (B);  % Arrow from A to B
\end{tikzpicture}

Use TikZ with DK.BeesGO

The DK.BeesGO use tikzjax Obsidian plugin to render TikZ code.

If you forked the DK.BeesGOand use it locally with Obsidian, then you can draw some fancy plots like below:

Example 1:

```tikz
\begin{document}
  \begin{tikzpicture}[domain=0:4]
    \draw[very thin,color=gray] (-0.1,-1.1) grid (3.9,3.9);
    \draw[->] (-0.2,0) -- (4.2,0) node[right] {$x$};
    \draw[->] (0,-1.2) -- (0,4.2) node[above] {$f(x)$};
    \draw[color=red]    plot (\x,\x)             node[right] {$f(x) =x$};
    \draw[color=blue]   plot (\x,{sin(\x r)})    node[right] {$f(x) = \sin x$};
    \draw[color=orange] plot (\x,{0.05*exp(\x)}) node[right] {$f(x) = \frac{1}{20} \mathrm e^x$};
  \end{tikzpicture}
\end{document}
```

Output (visible in local Obsidian):

\begin{document}
  \begin{tikzpicture}[domain=0:4]
    \draw[very thin,color=gray] (-0.1,-1.1) grid (3.9,3.9);
    \draw[->] (-0.2,0) -- (4.2,0) node[right] {$x$};
    \draw[->] (0,-1.2) -- (0,4.2) node[above] {$f(x)$};
    \draw[color=red]    plot (\x,\x)             node[right] {$f(x) =x$};
    \draw[color=blue]   plot (\x,{sin(\x r)})    node[right] {$f(x) = \sin x$};
    \draw[color=orange] plot (\x,{0.05*exp(\x)}) node[right] {$f(x) = \frac{1}{20} \mathrm e^x$};
  \end{tikzpicture}
\end{document}

---

Example 2:

```tikz
\usepackage{circuitikz}
\begin{document}
 
\begin{circuitikz}[american, voltage shift=0.5]
\draw (0,0)
to[isource, l=$I_0$, v=$V_0$] (0,3)
to[short, -*, i=$I_0$] (2,3)
to[R=$R_1$, i>_=$i_1$] (2,0) -- (0,0);
\draw (2,3) -- (4,3)
to[R=$R_2$, i>_=$i_2$]
(4,0) to[short, -*] (2,0);
\end{circuitikz}
 
\end{document}
```

Output (visible in local Obsidian):

\usepackage{circuitikz}
\begin{document}
 
\begin{circuitikz}[american, voltage shift=0.5]
\draw (0,0)
to[isource, l=$I_0$, v=$V_0$] (0,3)
to[short, -*, i=$I_0$] (2,3)
to[R=$R_1$, i>_=$i_1$] (2,0) -- (0,0);
\draw (2,3) -- (4,3)
to[R=$R_2$, i>_=$i_2$]
(4,0) to[short, -*] (2,0);
\end{circuitikz}
 
\end{document}

---

Example 3:

```tikz
\usepackage{pgfplots}
\pgfplotsset{compat=1.16}
 
\begin{document}
 
\begin{tikzpicture}
\begin{axis}[colormap/viridis]
\addplot3[
	surf,
	samples=18,
	domain=-3:3
]
{exp(-x^2-y^2)*x};
\end{axis}
\end{tikzpicture}
 
\end{document}
```

Output (visible in local Obsidian):

\usepackage{pgfplots}
\pgfplotsset{compat=1.16}
 
\begin{document}
 
\begin{tikzpicture}
\begin{axis}[colormap/viridis]
\addplot3[
	surf,
	samples=18,
	domain=-3:3
]
{exp(-x^2-y^2)*x};
\end{axis}
\end{tikzpicture}
 
\end{document}

---

Example 4:

```tikz
\usepackage{tikz-cd}
 
\begin{document}
\begin{tikzcd}
 
    T
    \arrow[drr, bend left, "x"]
    \arrow[ddr, bend right, "y"]
    \arrow[dr, dotted, "{(x,y)}" description] & & \\
    K & X \times_Z Y \arrow[r, "p"] \arrow[d, "q"]
    & X \arrow[d, "f"] \\
    & Y \arrow[r, "g"]
    & Z
 
\end{tikzcd}
 
\quad \quad
 
\begin{tikzcd}[row sep=2.5em]
 
A' \arrow[rr,"f'"] \arrow[dr,swap,"a"] \arrow[dd,swap,"g'"] &&
  B' \arrow[dd,swap,"h'" near start] \arrow[dr,"b"] \\
& A \arrow[rr,crossing over,"f" near start] &&
  B \arrow[dd,"h"] \\
C' \arrow[rr,"k'" near end] \arrow[dr,swap,"c"] && D' \arrow[dr,swap,"d"] \\
& C \arrow[rr,"k"] \arrow[uu,<-,crossing over,"g" near end]&& D
 
\end{tikzcd}
 
\end{document}
```

Output (visible in local Obsidian):

\usepackage{tikz-cd}
 
\begin{document}
\begin{tikzcd}
 
    T
    \arrow[drr, bend left, "x"]
    \arrow[ddr, bend right, "y"]
    \arrow[dr, dotted, "{(x,y)}" description] & & \\
    K & X \times_Z Y \arrow[r, "p"] \arrow[d, "q"]
    & X \arrow[d, "f"] \\
    & Y \arrow[r, "g"]
    & Z
 
\end{tikzcd}
 
\quad \quad
 
\begin{tikzcd}[row sep=2.5em]
 
A' \arrow[rr,"f'"] \arrow[dr,swap,"a"] \arrow[dd,swap,"g'"] &&
  B' \arrow[dd,swap,"h'" near start] \arrow[dr,"b"] \\
& A \arrow[rr,crossing over,"f" near start] &&
  B \arrow[dd,"h"] \\
C' \arrow[rr,"k'" near end] \arrow[dr,swap,"c"] && D' \arrow[dr,swap,"d"] \\
& C \arrow[rr,"k"] \arrow[uu,<-,crossing over,"g" near end]&& D
 
\end{tikzcd}
 
\end{document}

---

Example 5:

```tikz
\usepackage{chemfig}
\begin{document}
 
\chemfig{[:-90]HN(-[::-45](-[::-45]R)=[::+45]O)>[::+45]*4(-(=O)-N*5(-(<:(=[::-60]O)-[::+60]OH)-(<[::+0])(<:[::-108])-S>)--)}
 
\end{document}
```

Output (visible in local Obsidian):

\usepackage{chemfig}
\begin{document}
 
\chemfig{[:-90]HN(-[::-45](-[::-45]R)=[::+45]O)>[::+45]*4(-(=O)-N*5(-(<:(=[::-60]O)-[::+60]OH)-(<[::+0])(<:[::-108])-S>)--)}
 
\end{document}

---

Example 6:

```tikz
\usepackage{chemfig}
\begin{document}
 
\definesubmol\fragment1{
 
    (-[:#1,0.85,,,draw=none]
    -[::126]-[::-54](=_#(2pt,2pt)[::180])
    -[::-70](-[::-56.2,1.07]=^#(2pt,2pt)[::180,1.07])
    -[::110,0.6](-[::-148,0.60](=^[::180,0.35])-[::-18,1.1])
    -[::50,1.1](-[::18,0.60]=_[::180,0.35])
    -[::50,0.6]
    -[::110])
    }
 
\chemfig{
!\fragment{18}
!\fragment{90}
!\fragment{162}
!\fragment{234}
!\fragment{306}
}
 
\end{document}
```

Output (visible in local Obsidian):

\usepackage{chemfig}
\begin{document}
 
\definesubmol\fragment1{
 
    (-[:#1,0.85,,,draw=none]
    -[::126]-[::-54](=_#(2pt,2pt)[::180])
    -[::-70](-[::-56.2,1.07]=^#(2pt,2pt)[::180,1.07])
    -[::110,0.6](-[::-148,0.60](=^[::180,0.35])-[::-18,1.1])
    -[::50,1.1](-[::18,0.60]=_[::180,0.35])
    -[::50,0.6]
    -[::110])
    }
 
\chemfig{
!\fragment{18}
!\fragment{90}
!\fragment{162}
!\fragment{234}
!\fragment{306}
}
 
\end{document}

TikZ to SVG

You can use this LaTeX equations for web online editor to download the SVG figure for further editing inside InkScape software.

For using LaTeX equations for web with the above example code, please remove the heading \usepackage line and start with the \begin{document} line.