1. CS 102 Computers In Context (Multimedia)‏ 02 / 06 / 2009 Instructor: Michael Eckmann

2. Michael Eckmann - Skidmore College - CS 102 - Spring 2009 Today’s Topics Questions/comments? Let's read over the hw I assigned Review of reading pages 39-60 All the JES image functions covered in those pages Write a few more functions

3. Michael Eckmann - Skidmore College - CS 102 - Spring 2009 Calling functions What do we need to know to be able to call a function that already exists correctly?

4. Michael Eckmann - Skidmore College - CS 102 - Spring 2009 Some JES image functions makePicture getWidth, getHeight getPixel getPixels getX, getY getRed, getBlue, getGreen setRed, setBlue, setGreen distance getColor, setColor, makeColor pickAColor makeLighter, makeDarker writePictureTo show

5. Michael Eckmann - Skidmore College - CS 102 - Spring 2009 Try these Let's look at my solution to this: greetWrite a function named greet that takes in someone's name and displays a greeting to that person. For example if I call greet like this: greet('Mike')‏ –It should display Hello, Mike, nice to see you.

6. Michael Eckmann - Skidmore College - CS 102 - Spring 2009 Try these displayWrite a function named display that displays an image, given a file name as a parameter. display('boat.jpg')‏ –It should display the image boat.jpg noRedWrite a function named noRed that alters an image so that it has 0 for the red channel of each pixel. It should take in a picture object as a parameter and alter that picture. pic = makePicture('boat.jpg')‏ noRed(pic)‏ show(pic) # display the boat image after noRed set all reds to 0

7. Michael Eckmann - Skidmore College - CS 102 - Spring 2009 docstrings Docstrings are special comments describing the function, module, class or method being defined. Example: def factorial(num): """ factorial computes the factorial of the number num. num! = num * (num-1) * (num-2) *... * 1 returns an integer, the factorial of num """ fact = 1 while (num > 1): fact = fact * num num -= 1 return fact