creation date: 2025-02-10 11:57
modification date: 2025-02-10 11:57

XY Plots

\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} 

Circuit Diagrams

\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} 

Latice Structures

\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} 

3D Graph

\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}