2. Bar Charts Bar charts are graphs of rectangular bars with the length of the bars proportional to the value represented. Bar charts can be used to represent discrete data (data that changes over discrete intervals, not continuously). Bar charts are useful for showing trends over time. Bar charts are often more visually appealing than line graphs

3. Example http://www.w3schools.com/browsers/browsers_stats.asp w3schools.com Browser survey of their visitors: Month/Year Internet Explorer FirefoxChromeSafari Jan 2008 54.7%36.4%1.9% Jan 2009 44.8%45.5%3.9%3.0% Jan 2010 36.2%46.3%10.8%3.7% Jan 2011 26.6%42.8%23.8%4.0% Jan 2012 20.1%37.1%35.3%4.3% Jan 2013 14.3%30.2%48.4%4.2%

4. Example >> Explorer = [54.7; 44.8; 36.2; 26.6; 20.1; 14.3]; >> Firefox = [36.4; 45.5; 46.3; 42.8; 37.1; 30.2]; >> Chrome = [0; 3.9; 10.8; 23.8; 35.3; 48.4]; >> Safari = [1.9; 3.0; 3.7; 4.0; 4.3; 4.2]; >> Browser = [Explorer Firefox Chrome Safari] Browser = 54.7000 36.4000 0 1.9000 44.8000 45.5000 3.9000 3.0000 36.2000 46.3000 10.8000 3.7000 26.6000 42.8000 23.8000 4.0000 20.1000 37.1000 35.3000 4.3000 14.3000 30.2000 48.4000 4.2000 % browser is a 6 x 4 matrix (2-d array) of values. Each column represents the data from a different browser.

5. Example >> Year = [2008; 2009; 2010; 2011; 2012; 2013]; >> bar(Year,Browser); >> legend('Explorer','Firefox','Chrome','Safari') >> xlabel('Year'); ylabel('Percent of Users'); title('Browser Usage Statistics');