Assignment

Published date

Sept. 28, 2017

Due date

Oct. 9, 2017

Method of Submission

OCW-i

Upload answer1.ml at the respective page of OCW-i.

You need to register for this class to open the OCW-i assignment page.

Delayed Submission

Each submission is weighed according to half-value period of 10 days. That means if you submit a perfect answer 30 days after the due date, you will receive \(1/8\) the full points. In other words, you lose \(1 - 1/2^{1/10} \approx 6.7\text {%}\) points each day after the due date has passed. It is very wise to keep the due date.¹

READ the MANUAL FIRST

Read the OCaml Manual Chapter1 first. When you are finished, try to answer the following questions.

Your Mission

Download answer1.ml. This is a template file for your answers. You may find half-solved answers to the five problems described below. OCaml interpreter happily accept this file: (Feed this file to OCaml interpreter with ocaml answer1.ml from the command line and OCaml accepts it without any complaint.) However, answer1.ml contains inappropriate definitions at several places. For example area_of_circle and radius_of_circle always answers zeros which are clearly wrong answers in almost all cases.

Your mission is to correctly modify answer1.ml.

Problem 1. circle_area

Define a function named circle_area that takes a circle’s radius and gives its area.

Problem 2. radius_of_circle

Define a function named radius_of_circle that takes an area of a circle and gives its radius.

Hint

• Basic math functions are documented in Pervasives module.

Problem 3. circle_areas

Define a function named circle_areas that takes a list of circles’ radii and gives their areas.

Hints

• You may reuse the definition of circle_area.

• circle_areas [1.0; 3.0; 5.0] should give [3.14159265358979312; 28.274333882308138; 78.5398163397448315].

• You may want to use functions from the List module. You can equally easily solve this problem without using the List module.

Problem 4. mul_num

Define div_num that emulates faction over numbers: \(n_1 / n_2\).

Hints

• Look at the definition of add_num defined in Section 1.4

Problem 5. rotate

Define a function named rotate that takes a point coordinate (\(p\): mutable_point) and an angle in radian (\(\theta\): float) and performs rotation on \(p\) by \(\theta\) around the origin.

Hints

• Rotation matrix
• Section 1.5: Imperative features

Back to Top