CMSC 15100 - Fall 2006

Part 1 Define the functions celsius->kelvin and fahrenheit->celsius, and celsius->fahrenheit based on these formulas:

Degrees Celsius = (Degrees Fahrenheit - 32)* 5/9
Degrees Kelvin = Degrees Celsius + 273.16

Remember to write a contract, purpose statement, and examples before you write your functions' bodies.

Part 2 Now write the rest of the temperature-conversion functions:

fahrenheit->kelvin
kelvin->celsius
kelvin->fahrenheit

Part 3 Write three functions:

kelvin->thermometer
celsius->thermometer
fahrenheit->thermometer

Each function takes a number and draws a thermometer of the temperature, where a thermometer is an image that looks like one of these:


40C	90C	25C

The image is always 100 pixels tall and 10 pixels wide. A completely red thermometer corresponds to the boiling point of water (100 degrees Celsius), and a completely empty thermometer corresponds to the freezing point of water (0 degrees Celsius). You may assume that the temperature given is always between these ranges. In fact, it may be useful to assume that the temperature is always at least a little higher than freezing or a little lower than boiling; you may assume that too if you want.

Here are a few hints:

Don't write the hard part of this function three times. Instead figure out a way to reuse what you've already written.
Stacking images together Look up the move-pinhole function in the documentation.
The rectangle function requires you to give it exact integers that are greater than zero for the width and height; fractions and zero are not allowed. To make sure you give it an exact integer you may find it useful to round numbers occasionally; you can use the built-in DrScheme functions floor and ceiling for that purpose (look them up in the Help Desk for more information).

Jacob Matthews
jacobm at cs.uchicago.edu
Hinds 026

CMSC 15100 - Fall 2006 - Lab Assignment 1