Introduction to Matlab What is Matlab? Brief overview, purchasing & installation Using the Command Window As a calculator As a graphing tool To compute basic statistics Using the Editor to create scripts and functions Interactivity: Input/Output Non-standard statistics and simulation

What is Matlab? Matlab is a statistical analysis, visualization, and scripting language Used widely in the physical and engineering sciences Becoming more and more popular in the social sciences

What is Matlab? Matlab is a statistical analysis, visualization, and scripting language Used widely in the physical and engineering sciences Becoming more and more popular in the social sciences Excel? SPSS? SASS? Python?

Acquiring Matlab Visit: Matlab is available for purchase: Professional/academic license: $500 basic package (+$200 for statistics toolbox) Student license: $50 basic package (+$50 for statistics toolbox) Licenses are tied to the installation computer (Mac or PC) and do not expire. Visit: https://www.mathworks.com/products/matlab.html

1. Using the Command Window As a calculator Basic operations with scalars, vectors, and matrices As a graphing tool Scatter plots, line plots, bar graphs, histograms To compute standard statistics Mean, median, mode, quantile, max/min, sorting, and randomization T-tests, correlation, regression, polynomial fitting, ANOVAs

2. Using the Editor Window To create scripts: Save a list of commands Define iterative operations To create functions: Defining input and output variables

3. Interactivity Example 1: Survey questions Ask user a series of questions (of various formats) Save data in Matlab, and in Excel Example 2: Interact with an image Load and display an image of a face Ask user to click on the eyes and nose Save x,y positions of the mouse clicks

4. Nonparametric statistics Example: Bootstrap analysis Load a sample data set (heights from before) Compute the Bootstrap standard error of the mean Take an n-sample with replacement Record the mean of the n-sample Repeat many times Display the distribution of means

5. Other demos Face modeling

Future workshops Workshop 2: Matlab Research Tools for Social Scientists Friday, November 2, 3-5pm, Social Sciences 2, room 121 This workshop I will cover a variety of research tools in Matlab, including designing surveys and behavioral studies, randomizing variables and conditions, collecting user responses (button presses, mouse clicks, reaction times), saving and loading data individual and group data. Workshop 3. Data Analysis and Plotting in Matlab Friday, February 1, 3-5pm, Social Sciences 2, room 121 This workshop will cover more advanced examples of data analysis and plotting using Matlab’s statistics toolbox. Statistical tests included t-tests, ANOVA, correlation, and multiple regression. Plotting functions included scatter, line plots, bar graphs, and histograms. Workshop 4. Visualizing Multivariate Data in Matlab Friday, February 15, 3-5pm, Social Sciences 2, room 121 In this 2-hour workshop I presented methods for plotting and visualizing multivariate data involving 3 or more variables. These included 3D scatter plots, surface plots, and dynamic displays using Matlab video and graphing tools.

Future workshops (cont.) Workshop 5. Introduction to Matlab (refresher) Friday, April 12, 3-4pm, Social Sciences 2, room 121 This workshop will cover the basics of Matlab; using the Command Window for defining variables, conducting standard statistical analyses, making 2D plots, and using the Editor to create iterative scripts. Workshop 6. Nonparametric statistics Friday, April 26, 3-5pm, Social Sciences 2, room 121 This workshop will introduce nonparametric statistics, including rank-order statistics and the Bootstrap Method, that involve minimal assumptions about the underlying data distributions. Workshop 7. Computational simulation Friday, May 10, 3-5pm, Social Sciences 2, room 121 This workshop will introduce the use computational simulations for modeling irregular or non-parametric data. Examples include leave-one-out analyses, Monte Carlo simulation, and iterative parameter searches. .

Questions? Please visit me during my statistical consultation office hours: Fall quarter: Tuesdays 2-4pm (or by appointment), SS2-377 Winter & Spring: TBA (check https://csass.ucsc.edu/consulting/consultants.html ) Email me: ndaviden@ucsc.edu All workshop materials will be posted at: https://davidenko.sites.ucsc.edu/matlab-workshops/