http://secant.cs.purdue.edu/ 2008-07-24T15:11:37-04:00 http://secant.cs.purdue.edu/ http://secant.cs.purdue.edu/lib/images/favicon.ico text/html 2008-07-24T12:14:13-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/cs190c:lab14?rev=1216916053&do=diff Lab 14: First Hour For today's lab, you are to work independently. You will have one hour to complete the assignment. If, at the expiration of this one hour, you are unfinished, submit what you have finished. Write a program that will encrypt and decrypt simple lower-case strings using a substitution cipher, like a cryptoquote. The key, or the mapping from the plaintext letters to the code letters is given in . This is only one possible mapping, there are 26!-1 different mappings. text/html 2008-07-24T12:13:51-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/cs190c:lab13?rev=1216916031&do=diff For today's lab, we will be investigating the benefits of using an efficient algorithm. We will be searching datasets ranging in size from 100 to 10,000 elements. * Sizes of the lists should be from 100 to 10,000, stepping by 100. The list should be the numbers from 0 to N-1. sizes = range(100,10000, 100) text/html 2008-07-24T12:13:30-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/cs190c:lab12?rev=1216916010&do=diff Today's in-lab project is similar to the movie-matching game called six degrees of Kevin Bacon. We are providing you a data file that represents an undirected graph where there exists an edge between an actor and a movie if that actor was in that movie. Thus, your problem is to leverage NetworkX such that you can perform lookups of the shortest paths between actors. text/html 2008-07-24T12:13:02-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/cs190c:lab10?rev=1216915982&do=diff Lab 10: First Hour * Go over the [word frequency program]. * In Lab problem: * Read in the file [dictionary.txt] and create a Python dictionary that contains each word in the file. Then, prompt the user for a file to spell check. Print out each word that is in the user's file that does not reside in the dictionary. The words you print out should be unique and in alphabetical order. Use the word frequency program as a template of how to split apart the words in the file. You should … text/html 2008-07-24T12:12:37-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/cs190c:lab9?rev=1216915957&do=diff Lab 9: Part 1 * Go over trees from Wednesday lecture * [Binary Tree] * [File System Tree] * In-lab assignment * To the binary tree program, you are to add a function that performs a post order traversal of the tree. (This is what is provided as input to create a tree.) This means that if you are at a node, add the traversal of the left node to the string, then the traversal of the right node to the string, then the node itself. After writing the function, write a __main__ pr… text/html 2008-07-24T12:11:43-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/cs190c:lab3?rev=1216915903&do=diff Lab 3: Examples using functions (first hour) ## What do these functions return? def mystery(x): if x > 8: return 1; if x < 3: return 5; else: return 10; val = 2 mystery(val) mystery(mystery(val)) mystery(mystery(mystery(val))) text/html 2008-07-24T12:11:11-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/cs190c:lab4?rev=1216915871&do=diff * Plot function for vertical percolation in Matplotlib * the function is f(p) = 1–(1-p^n)^n * plotting multiple figures in different frames [ code] and plotting all graphs in one frame [ code] * While loop that loops until something is true. text/html 2008-07-24T12:10:34-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/cs190c:lab6?rev=1216915834&do=diff Lab 6: First hour * Returned exam and discussed related issues. [ Exam 1 solutions.] * Spoke about academic misconduct. * High level discussion is acceptable collaboration on the problem sets. Copying of code is cheating, and will be reported. text/html 2008-07-24T12:09:37-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/cs190c:lab7?rev=1216915777&do=diff * Discussion of numerical stability * Binary decimal structure. Is it possible to represent every number exactly? >>> a = 3.1 >>> a 3.1000000000000001 >>> a = 35.95 >>> a 35.950000000000003 * IEEE floating point structure * Numpy's round allows you to choose the number of decimal places, but how can you floor a decimal to two places? a = floor(a * 100.0)/100.0 text/html 2008-07-24T12:08:45-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/cs190c:lab8?rev=1216915725&do=diff The variance of n sample values \(x_1\), \(x_2\), ... , \(x_n\) is one measure of statistical dispersion, obtained by averaging the squared distance of the sample values from the expected value (mean). The mean captures the location of a distribution and the variance captures the degree of the values being spread out. The square root of the variance is called the standard deviation. text/html 2008-07-21T13:44:56-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/start?rev=1216662296&do=diff SECANT is a community building project funded through the NSF CPATH (Pathways to Revitalized Undergraduate Computing Education) program. The goal of SECANT is to bring together scientists who recognize that computer science has become indispensable to scientific inquiry and is set to permeate science in a manner that is transformative, changing computing from a service discipline for the sciences into a fundamental paradigm for science in general. The effort complements Purdue's recently adopted… text/html 2008-07-21T13:42:58-04:00 Susanne Hambrusch http://secant.cs.purdue.edu/sidebar?rev=1216662178&do=diff Community * Join * Event Calendar * Members * Related Websites * Contact Info * Workshop Videos 2008 Workshop * Local Info 2007 Workshop * Description * Agenda and Talks * Panel Descriptions * Participants * Local Info