Friday, December 5, 2008

Star Plots

A star plot is a graphical data analysis method used for examining the relative behavior of all variables in a multivariate data set. This is an example of several different star plots. They show different observations about different cars, including Price, Mileage (MPG), 1978 Repair Record (1 = Worst, 5 = Best), 1977 Repair Record (1 = Worst, 5 = Best), Headroom, Rear Seat Room, Trunk Space, Weight, and Length.

http://www.itl.nist.gov/div898/handbook/eda/section3/gif/starplot.gif

Correlation Matrix

A correlation matrix lists the variable names down the first column and across the first row. The diagonal of a correlation matrix always consists of ones. In every correlation matrix there are two triangles that are the values below and to the left of the diagonal and above and to the right of the diagonal. A correlation matrix is always a symmetric matrix. The Correlation map above shows the correlation between different regions (US, Japan, UK, Europe, Asia, and Engineering Markets) and principal bond, forex markets, equity regions, sectors and styles of investing.



http://www.investors-routemap.co.uk/images/correlation.gif

Similarity Matrix

A similarity matrix is a matrix of scores which show the similarities between two data points. They are generally used in sequence alignment. The higher the score the more similar characters it receives. This is a similarity matrix comparing different types of organisms. The red line that goes down the center suggest high similarity or exactness. The different shades of blue (and green) represent how similar the organisms are.





http://www.mbioekol.lu.se/staff/dag/genomeconservation_similarity_matrix.jpg

Thursday, December 4, 2008

Stem and Leaf Plot

Stem and leaf plot is a way to show quantitative data in a graphical format to help visualize the distribution among categories. It came about from teh work of Arther Bowley in the early 1900's. The plot above is a stem and leaf plot of the ages of people that were at a family reunion. Most of the people were in their 30's. There were 3 children, one in their 40's, two in their 50's, and one in their 80's.


http://www.eduplace.com/math/mhm/5/06a/ts_5_6a_wi-1.gif

Saturday, November 29, 2008

Box Plot

Box plots are very useful to graph groups of numerical data through their five number summaries. It was invented in 1977 by John Tukey who was an American. They are also used to depict differences in populations without making assumptions on statistical distribution. This is a Box Plot of votes favoring the Coalition TPP. The majority of rural voters voted in favor, while less than half of the voters in the Inner Metro area were not in favor.


http://www.ozpolitics.info/election2004/e2004-boxpolt-seat-type-by-CTPP-vote.png

Sunday, November 16, 2008

Histogram


A histogram is a graphical display of tabulated frequencies. It shows what proportion of cases fall into each of several categories. There is a difference between a histogram and a bar chart in the sense that it is the area of the bar that dictates the value, not the height, which is a very important difference particularly when the variables are not all the same width. The histogram above show the different employee's salaries.



http://www.whizdog.com/qmblog/images/histogram_032005_5927_image001.gif

Tuesday, November 4, 2008

Parallel Coordinate Graph

Multivariate relations are obtained through the use of parallel coordinate graphs. Specific properties of the relationship correspond to the geometrical properties of the graph. This is a parallel cooridinate graph of baseball statistics. It shows statistics from many different players. The top of the graph is the lead for that particular statistic.


http://www.matthewtavares.com/baseball_report/graph_allteams.bmp