Asymptote: Drawing

Asymptote (Vector Graphics Language)
Getting Started - Basics - Drawing - Labeling - Filling - Useful functions - Examples - Macros and Packages

Help - Reference - Advanced Asymptote - 3D Graphics - CSE5 Package - How to

Dots

Let us start off with the most basic of this basic command: drawing a dot.

To draw a dot, simply write the following code:

dot((0,0));

You can fix certain attributes to this dot, such as color:

dot((0,0),blue);

[asy] dot((0,0),blue); [/asy]

To make the dot an open dot, you could draw a really small circle with a white fill and black outline:

filldraw(circle((0, 0), 0.02), white, black);

For example:

[asy] draw((0, 0) -- (0, 1), EndArrow(10)); label("$(0, 1)$", (0, 1), NW); draw((0, 0) -- (1, 0), EndArrow(10)); label("$(1, 0)$", (1, 0), SE); draw((0, 0) --(1, 1), blue); label("$x = y$", (0, 0) -- (1, 1), SE, blue); filldraw(circle((0, 0), 0.02), white, black); [/asy]

Or you could do this craziness:

dot((0,0),filltype=FillDraw(fillpen=white, drawpen=black));

For example:

[asy] draw((0,1)..(0,0)..(1,0), Arrows(10)); dot((0,0),filltype=FillDraw(fillpen=white, drawpen=black)); [/asy]

Circles

In this article, draw(circle((0,0),5));

We see that the first draw() command creates the circle, which uses the circle() command. How this works is that the circle() command produces a path in which the draw() command draws. Within the circle command, we see the center point is located at the cartesian plane point (0,0), and it has a radius of 5.

This code produces:

[asy] draw(circle((0,0),5)); [/asy]

Once again, we can fix certain attributes to this code:

draw(circle((0,0),5),red+linewidth(1));

[asy] draw(circle((0,0),5),red+linewidth(1)); [/asy]

And we can fill the inside:

filldraw(circle((0,0),5),green,red+linewidth(1));

[asy] filldraw(circle((0,0),5),green,red+linewidth(1)); [/asy]

Ellipse

Another rounded figure we can create is the ellipse.

draw(ellipse((0,0),5,3));

In this case, the (0,0) is the center of the ellipse, the 5 is the length of the semi-major axis and the 3 is the length of the semi-minor axis. This results in:

[asy] draw(ellipse((0,0),5,3)); [/asy]

Once again, we can fix attributes and fill the inside.

filldraw(ellipse((0,0),5,3),green,red+linewidth(1));

[asy] filldraw(ellipse((0,0),5,3),green,red+linewidth(1)); [/asy]

Unit- Paths

There are several useful pre defined paths for drawing things like unit squares, unit circles, etc. Just use the unit- paths!

You can use the

unitsquare 
unitcircle 

paths for 2D. A list of Unit- paths for 3D can be found in the "Definitions": section of Asymptote: 3D graphics

Here is the unitsquare command:

draw(unitsquare); yields [asy] draw(unitsquare); [/asy]

And the unitsphere command.(Note: you have to import the three module for this to work.)

import three; draw(unitsphere,pink); yields [asy]import three; draw(unitsphere,pink);[/asy]

Since the unit- variables are paths, you can assign pen, fill them, and define other paths as them:


path u=unitcircle;
pen p=red+dashed;
draw(u,p);

yields

[asy] path u=unitcircle; pen p=red+dashed; draw(u,p); [/asy]