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: pair C=(0,0); int a=24; pair A=C+(0, a); pair B=A+(10,0); pair E=C-(0,a); pair D = E -(18,0);

draw(C--A--B--C--D--E--C);

draw(rightanglemark(C, A, B, 60)); draw(rightanglemark(C,E,D, 60));

label("", C, W); label("", A, NW); label("", B, NE); label("", E, SE); label("", D, SW);

int f=1; pair F=(A+C)/2; pair G=F-(f,0); pair H=F+(f,0); pair I=(C+E)/2; pair J=I-(f,0); pair K=I+(f,0); draw(G--H); draw(J--K);

label("", (D+E)/2, S); label("", (A+B)/2, N); label("", (B+C)/2, SSE); label("", (D+C)/2, NNW); You can fix certain attributes to this dot, such as color:

dot((0,0),blue);

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:

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

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

And we can fill the inside:

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

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 major axis and the 3 is the length of the minor axis. This results in:

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

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

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

import three; draw(unitsphere,pink); yields

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