# 2D Coordinate Plane

I want to sketch a plane to illustrate the relations between the Polar and the Cartesian coordinate systems, but I have no idea how to make it look good. I need some help, because all I've done is this:

\documentclass{standalone}

\usepackage{tikz}

\begin{document}

\begin{tikzpicture}
\draw[very thin,color=gray] (-3,-3) grid (3,3);
\draw[->] (-3,0) -- (3,0) node[right] {$x$};
\draw[->] (0,-3) -- (0,3) node[above] {$y$};
\draw[->] (0,0) -- (2,1)            node[right] {$\vec{r}$};
\end{tikzpicture}

\end{document}


It's the closest I got.

here's how it should look like \documentclass[tikz, border=1 cm]{standalone}
\usetikzlibrary{angles,quotes}
\begin{document}
\begin{tikzpicture}
%\draw[very thin,color=gray] (-3,-3) grid (3,3);
\coordinate (o) at (0,0);
\coordinate (r) at (2,1);
\coordinate (x) at (1,0);
\draw[->] (-3,0) -- (3,0) node[right] {$x$};
\draw[->] (0,-3) -- (0,3) node[above] {$y$};
\draw[->] (o) -- (r) node[right] {$\vec{r}$};
\draw[dashed] (o|-r) node[left]{$y$} -- (r) -- (r|-o) node[below]{$x$};
\pic[draw, "$\varphi$", angle eccentricity=1.5] {angle = x--o--r};
\node[below left] {$o$};
\end{tikzpicture}
\end{document} • You beat me on this one ;) +1 Sep 23 at 18:25
• Thank you very much! You helped me a lot! Where can I read about Tikz? There are so many Tikz- tutorials about circuits (for e. g. CircuiTikZ), but I din't find any good manuals on Tikz in general. Do you know any? Thank you again and have a nice day! Sep 24 at 14:09
• Yes - simply read the manual. You probably already have it on your computer as part of a LaTeX installation, or find it here: ctan.org/pkg/pgf?lang=en. The manual is huge, but well formed - just read the sections you need. Sep 24 at 18:56

I propose a solution with pstricks:

\documentclass{article}
\usepackage{pst-plot, pst-eucl}

\begin{document}

\begin{pspicture}
\psset{arrowinset=0.1, linejoin=1, ticks=none, labels=none, unit = 1.5cm}
\psaxes{->}(0,0)(-3,-3)(3,3)[$X$,-30][$Y$,60] \uput[dl](0,0){$O$}
\psline{->}(0,0)(2,1) \uput(2,1){$\vec{r}$}
\pnodes(0,0){O}(2,1){R}(2,0){H}
\pstMarkAngle[MarkAngleRadius=0.5, LabelSep=0.75\cite{}, arrows=->]{H}{O}{R}{$\varphi$}
\psCoordinates[linestyle=dashed, linewidth=0.5pt, markPoint=false](2,1) \uput[d](2,0){$x$}\uput[l](0,1){$y$}
\end{pspicture}

\end{document} • Thank you very much, I didn't even know about psticks package. Do you have any tutorials about this package? Thank you again and hope you have a nice day! Sep 24 at 14:25
• I don't know tutorials, but you may look at the pstricks web page on CTAN. Furthermore, the documentation is very well done. For me, it has the advantage to be less verbose than tikz/pgf, and to use a latex-like syntax (actually it is some kind of interface between latex and postscript.) Sep 24 at 16:28