How to convert polar coordinates to cartesian coordinates

Question

I am new to tikz. I am using the following code (Polar co-ordinates)

\def\radius{12cm}

\begin{tikzpicture}

\foreach \x in {0,10,...,350}
  {

\draw  [shading=radial, inner color=white, outer color=red!15,draw=white]  
(\x:\radius) circle (1);

  };

\foreach \x in {0,10,...,350}

  {

\node[scale=3.4] at (360-\x+90:\radius) {t};

  };



\end{tikzpicture}

The code works.

But when I use the code (converting to Cartesian co-ordinates)

\foreach \x in {0,10,...,350}
  {

\node[scale=3.4] at (\radius\*cos(360-\x+90), \radius\*sin(360-\x+90)) {t};

  };

error is generated. My search resulted in

TikZ does not use square coordinates but polar one, how to change it in order to use Cartesian coordinates?

But I am unable to do that. How it can be done? Thanks in advance.

Welcome to TeX.SX! A tip: If you indent lines by 4 spaces, they'll be marked as a code sample. You can also highlight the code and click the "code" button (with "{}" on it). — Jesse, Nov 23 '14 at 02:39
Your question is solved here: http://tex.stackexchange.com/questions/114150/spherical-coordinates-in-tikz-3d — Herman Jaramillo, Nov 23 '15 at 13:43

score 5 · Accepted Answer · answered Nov 23 '14 at 02:44

You need to protect the math operation with braces. Then your code works as is (after removing the backslash before *)

\def\radius{12cm}
\begin{tikzpicture}
\foreach \x in {0,10,...,350}{
\node[circle,shading=radial, inner color=white, outer color=red!15,scale=3.4] 
    at ({\radius*cos(360-\x+90)},{\radius*sin(360-\x+90)}) {t};
}
\end{tikzpicture}

How to convert polar coordinates to cartesian coordinates

1 Answers1