Analytic Methods in Social Ecology Summer Semester 2010 Mag. Christoph Plutzar Dr. Julia K. Steinberger

Today’s course plan Introductions –name, background, interests –Any specific wishes from this class? Practical & administrative information –Course plan –How it will function: alternate lectures/practice, work in groups, save work for next time. –Course wiki Course-related information –Grade requirements Getting started!

Class schedule MonthMarchAprilMay Date: Friday Class # 5,19,26 1, 2, Class times: 9 AM – 17 PM, location SR5 (usually) –2 breaks (morning & afternoon), lunch (not today!) Seminar contents 1.Lectures 2.Exercises 3.Discussions/questions

Class online Class website: Content: –Presentations –References –Software –Links English + specialized vocabulary Please always stop us when you don’t understand a word or a concept (or we’re speaking too fast)

Requirements for a positive grade Participation and completion of exercises (all class components): 2/3 Final exam on class materials (take notes!!!): 1/3 Goal: Proficiency at basic analysis: you can do it yourself Scientific literacy of further methods: you can understand what the goal of the method is

Syllabus (so far) March 5th: · Introduction to class (form groups, where to find information, do and save class work). (JKS) · Beginning data handling and analysis in excel. o Basic data types (CP) o Unit conversion, extensive and intensive variables. (JKS) o Basic statistical measure: mean, variance, standard deviation, coefficient of variation and so on (CP) March 19th: Visualization and presentation of data: do's and don'ts. Appropriate use of different types of graphs. Guidelines for charts and tables for presentations and publications. linear vs. logarithmic scales: what is a logarithmic scale? When should it be used for representation, or for data analysis, for intensive or extensive variables? Time-series data: calculating growth rates, graphical representation of time series data (indexation). March 26th: introduction to computer language Octave for data analysis. Basics of scripting languages. Assigning and manipulating variables in Octave. Reading in data (concept of NA), manipulating and graphing data, labeling data points. Log and linear plotting in Octave. Saving work as a script. Discussion of differences between excel and Octave: when to use which? April 30th: Linear regression: explanation of concept and method. Examples of linear regressions: lin-lin, log-lin, log-log. How to plot the results of a log log regression in excel. Linear regression in Octave, in linear and log space, understanding and plotting results. When is a result significant? Concept of co-linearity of variables, multiple variable regression in Octave, interpretation of results. Discussion of factor analysis, cluster analysis. May 28th: Introduction to Geographical Information Systems.

Getting started Data types Unit conversion, extensive & intensive variables Basic descriptive statistics.

Intensive and extensive variables Extensive variable: grows proportionally to scale of system –System x 2 => variable x 2, system / 2 => variable / 2 Intensive variable: does not change when system size changes Examples? –Extensive: volume, mass, population, area, GDP, crop production,... –Intensive: density, income, population density, crop yield per ha,... How do you obtain intensive variables from extensive? –Intensive = extensive / other extensive –Units? How do you obtain extensive variables from intensive?

Extensive/Intensive cont. Extensive or intensive? –Imports as a share of total consumption –Percentage of meat in diet –Average diet (kcal/cap/day) –Population of Vienna –Average population of Vienna’s districts –Energy consumption (Joules / year) –Energy per population density –Averages and percentages in general? What is the point of each type of variable? When would you use intensive vs. extensive?

A quick note on inverses What is “the inverse of X”? –Inverse of X = 1 / X = X -1 –Review of exponents? If X is large, inverse is small, and if X is small, inverse is large. When are X and inverse equal? What are the units of the inverse of population density? –The inverse of income? x Y = X -1

Unit conversion! First and last warning: every excel column/row, every plot axis, EVERY number in this class must have (correct) units! X (some units) = ? (other units) Need to know: 1 (some units) = a (other units) In words: “there are a (other units) in 1 (some units)” “there are 1000 (meters) in 1 (km)” In math: 1 = (a other units) / (1 some units) Then: X (some units) = ? (other units) = X (some units) * 1 = X (some units)* (a other units) / (1 some units) = X * a (other units).

Exercise 10 km = ? meters If 1 kWh = 3.6 MJ, how many kWh are 5 MJ? –5 MJ = ? kWh –1 MJ = a kWh. Since 1 kWh = 3.6 MJ, a = 1/3.6 –5 MJ = 5 x a kWh = 5 x (1/3.6) kWh = kWh. 1 km 2 = 100 hectares (ha). If population density is 100 cap/km 2, what is it in cap/ha? what is the population density (cap/km 2 ) of a country with 8 million people and 8 million ha? –Starting units are: (million cap)/(million ha) = a (cap/km 2 ) = 1’000’000/ (1’000’000/100) (cap/km 2 ) = 100 (cap/km 2 ) –So: 8/8 (million cap/ million ha) = 1 (million cap/million ha) = 1 x 100 (cap/km 2 ) = 100 (cap/km2) –Or: 1e2 cap Exponents – scientific notation (1e3, 1e-4, 7*1e5...)