Introduction

We’ll use Haskell to draw diagrams. The Diagram type can be displayed directly in the web page.

Coordinate System

Circle

Rectangle

Putting two diagrams together

The <|> operator combines two diagrams into one diagram.

Notice that the square is on top of the circle. How can we put the circle on top of the square?

Task: “Do not enter” sign

How can we draw the following figure?

(Hint: The length measurements are 2, 5, and 8.)

Moving

The move function shifts a diagram in space.

Combining multiple diagrams

Instead of using <|>, we can use union to combine diagrams. union takes a list of diagrams.

Using list comprehensions

We can use list comprehensions to express diagrams.

Task: stack of coins

How can we draw this stack of coins using list comprehensions?

(Hint: The circles’ diameter is 4.)

Task: stairs

(Hint: We use -5, 1, 2, 5.)

Task: Circles

Other interesting diagrams

Colors

Pre-defined colors: black, gray, white, red, green, blue, yellow

Task: “Do not enter” sign with color

How can we draw the following figure?

Rotation

Task: black star

(Hint: the size is 10.)

Task: clock face

Line segment

Task: dandelion

Other basic building blocks