MHB Drawing a Clockwise Rectangle on the Complex Plane with Tikz

[Dustinsfl]

How can I draw a rectangle oriented clockwise on the complex plane with vertices on (0,0), (0,4), (10,4), and (10,0)?

I am guessing the tikz package needs to be used but I am not skilled in making pictures.

 

[Evgeny.Makarov]

If you say \usepackage{tikz}, then you can do

\tikz\draw (0,0) -- (0,4) -- (10,4) -- (10,0) -- cycle;

or

\begin{tikzpicture}
\draw (0,0) -- (0,4) -- (10,4) -- (10,0) -- cycle;
\end{tikzpicture}

What do you mean by a rectangle "oriented clockwise"?

I am sure you can easily do this using other LaTeX packages, but I don't know them very well.

 

[Dustinsfl]

Clockwise is the path you would take around the rectangle.

Ok so that worked but I also want the rectangle on the coordinate axis with arrows along the path and the axes labeled at at 0, 10 and 4. Is there a way to make the rectangle not as big on the pdf?

 

[Evgeny.Makarov]

Well, after a rectangle is finished being drawn, nobody can tell whether it was drawn clockwise or counterclockwise. So I don't see the meaning in stipulating that it is oriented clockwise.

 

[Dustinsfl]

Well, after a rectangle is finished being drawn, nobody can tell whether it was drawn clockwise or counterclockwise. So I don't see the meaning in stipulating that it is oriented clockwise.

I need arrows on the rectangle showing its orientation of clockwise.

 

[Chris L T521]

If you say \usepackage{tikz}, then you can do

\tikz\draw (0,0) -- (0,4) -- (10,4) -- (10,0) -- cycle;

or

\begin{tikzpicture}
\draw (0,0) -- (0,4) -- (10,4) -- (10,0) -- cycle;
\end{tikzpicture}

What do you mean by a rectangle "oriented clockwise"?

I am sure you can easily do this using other LaTeX packages, but I don't know them very well.

Although I've used Tikz for complicated diagrams and images before, I never knew about the cycle option. Thanks for posting that! (Nod)

 

[Evgeny.Makarov]

Although I've used Tikz for complicated diagrams and images before, I never knew about the cycle option.

Yes, and besides shortening the notation, this option causes TikZ to create a proper join between the first and last segment. Here is a picture from TikZ manual.

https://lh4.googleusercontent.com/-k6SyrvG_Yns/T1QBS2e8I6I/AAAAAAAABbA/UyiDOLix9_A/s800/join.png

Here is the code for a rectangle with arrows.

\usetikzlibrary{arrows}
\begin{tikzpicture}[>=stealth',scale=.5]
\draw[->] (-1,0) -- (11,0);
\draw[->] (0,-1) -- (0,5);
\node[below left] at (0,0) {0};
\node[below] at (10,0) {10};
\node[left] at (0,4) {4};
\draw[thick,->] (0,0) -- (0,2);
\draw[thick,->] (0,2) -- (0,4) -- (5,4);
\draw[thick,->] (5,4) -- (10,4) -- (10,2);
\draw[thick,->] (10,2) -- (10,0) -- (5,0);
\draw[thick] (5,0) -- (0,0);
\end{tikzpicture}

This example uses the scale= option, which can be used in each \draw instruction individually or can apply to the whole picture if specified after \begin{tikzpicture}. It affects the specified coordinates, not the line lengths. The option -> adds the arrow tip only to the end of the path, so the rectangle has to consist of several paths.

A more sophisticated way is to use the decorations library.

\usetikzlibrary{arrows,decorations.markings}
\begin{tikzpicture}[>=stealth',scale=.5]
\draw[->] (-1,0) -- (11,0);
\draw[->] (0,-1) -- (0,5);
\node[below left] at (0,0) {0};
\node[below] at (10,0) {10};
\node[left] at (0,4) {4};
\draw[
  thick,
  decoration={
    markings,
    mark=at position 1/14 with {\arrow{>}},
    mark=at position 9/28 with {\arrow{>}},
    mark=at position 4/7 with {\arrow{>}},
    mark=at position 23/28 with {\arrow{>}}},
  postaction={decorate}] (0,0) -- (0,4) -- (10,4) -- (10,0) -- cycle;
\end{tikzpicture}

One advantage is that this allows using the cycle construction, which, as said above, create the correct join at (0, 0). I agree that the syntax of the decorations is rather confusing. (Smile)

 

[Dustinsfl]

Yes, and besides shortening the notation, this option causes TikZ to create a proper join between the first and last segment. Here is a picture from TikZ manual.

https://lh4.googleusercontent.com/-k6SyrvG_Yns/T1QBS2e8I6I/AAAAAAAABbA/UyiDOLix9_A/s800/join.png

Here is the code for a rectangle with arrows.

\usetikzlibrary{arrows}
\begin{tikzpicture}[>=stealth',scale=.5]
\draw[->] (-1,0) -- (11,0);
\draw[->] (0,-1) -- (0,5);
\node[below left] at (0,0) {0};
\node[below] at (10,0) {10};
\node[left] at (0,4) {4};
\draw[thick,->] (0,0) -- (0,2);
\draw[thick,->] (0,2) -- (0,4) -- (5,4);
\draw[thick,->] (5,4) -- (10,4) -- (10,2);
\draw[thick,->] (10,2) -- (10,0) -- (5,0);
\draw[thick] (5,0) -- (0,0);
\end{tikzpicture}

This example uses the scale= option, which can be used in each \draw instruction individually or can apply to the whole picture if specified after \begin{tikzpicture}. It affects the specified coordinates, not the line lengths. The option -> adds the arrow tip only to the end of the path, so the rectangle has to consist of several paths.

A more sophisticated way is to use the decorations library.

\usetikzlibrary{arrows,decorations.markings}
\begin{tikzpicture}[>=stealth',scale=.5]
\draw[->] (-1,0) -- (11,0);
\draw[->] (0,-1) -- (0,5);
\node[below left] at (0,0) {0};
\node[below] at (10,0) {10};
\node[left] at (0,4) {4};
\draw[
  thick,
  decoration={
    markings,
    mark=at position 1/14 with {\arrow{>}},
    mark=at position 9/28 with {\arrow{>}},
    mark=at position 4/7 with {\arrow{>}},
    mark=at position 23/28 with {\arrow{>}}},
  postaction={decorate}] (0,0) -- (0,4) -- (10,4) -- (10,0) -- cycle;
\end{tikzpicture}

One advantage is that this allows using the cycle construction, which, as said above, create the correct join at (0, 0). I agree that the syntax of the decorations is rather confusing. (Smile)

You are great with the tikz stuff. On mhf, you would help with my commutative diagrams. Where do you get a manual for this?

 

[Chris L T521]

You are great with the tikz stuff. On mhf, you would help with my commutative diagrams. Where do you get a manual for this?

I have it somewhere, but it's available here.

EDIT: The most up-to-date one is this one: http://math.mit.edu/~dspivak/files/pgfmanual.pdf

 

[Evgeny.Makarov]

EDIT: The most up-to-date one is this one: http://math.mit.edu/~dspivak/files/pgfmanual.pdf

This is for version 2.0. Here is http://www.ctan.org/tex-archive/graphics/pgf/base/doc/generic/pgf/pgfmanual.pdf on CTAN. Besides, it is included in the distribution at doc/generic/pgf/pgfmanual.pdf.