The Analytica User Group is a way for Analytica users to support each other by sharing tips and function libraries. It includes a webinar series with tutorials and demonstrations on key Analytica features.

Webinar Series

There is usually an Analytica user webinar each week, presented by a user from Lumina or elsewhere. Webinars include demonstrations and tutorials on key issues for Analytica users, sometimes on how to use existing features more effectively, and sometimes on features of new or upcoming releases.

Webinars are interactive, using Citrix Gotomeeting to share screens and a phone teleconference. Questions, comments, and tangents are welcome. Webinars are a great place to learn more about Analytica and other related topics. Seats are limited. To sign up for a particular webinar, see "How to Attend" below. Presentations may last anywhere from 20 to 90 minutes (with an estimate provided upfront).

Lumina often records User Group webinars, including audio and screensharing, and makes them available so that those who couldn't make it at the original time can view them later.

Schedule of Upcoming Webinars

Assessment of Probability Distributions

Date and Time: March 6, 2008 10:00am Pacific Standard Time

Presenter: Lonnie Chrisman, Lumina Decision Systems

Abstract

When building a quantitative model, we usually need to come up with estimates for many of the parameters and input variables that we use in the model. Because these are estimates, it is good idea to encode these as probability distributions, so that our degree of subjective uncertainty is explicit in the model. The process of encoding a distribution to reflect the level of knowledge that you (or the experts you work with) have about the true value of the quantity is referred to as probability (or uncertainty) assessment or probability elicitation.

This webinar will be a highly interactive one, where all attendees are expected to participate in a series of uncertainty assessments as we explore the effects of cognitive biases (such as over-confidence and anchoring), understand what it means to be well-calibrated, and utilize scoring metrics to measure your own degree of calibration. These exercises can help you improve the quality of your distribution assessments, and serve as tools that can help you to when eliciting estimates of uncertainty from other domain experts.

If you plan to attend this talk, please download this model: Probability assessment.ana, but do not open the model until instructed to during the webinar.

Correlated and Multivariate Distributions

Abstract

This talk will discuss various techniques within Analytica for defining probability distributions with specified marginal distributions, and also being correlated with other uncertain variables. Techniques include the use of conditional and hierarchical distributions, multivariate distributions, and Iman-Conover rank-correlated distributions.

How to Attend

To attend, you need to sign up by contacting Lumina at webinars@lumina.com or (650) 212-1212. Attendence is limited to 15 people, so don't sign up unless you sincerely intend to attend. Also, sign up at least a day prior, since the webinar may be cancelled if there are few pre-registered participants.

These Webinars are FREE to users who have an up-to-date annual maintenance subscription (MTS). If you are unsure, check with mailto:sales@lumina. For those without MTS, an attendence fee of US$100 is charged.

How to be a Presenter

Being a presenter at an Analytica webinar provides an opportunity to make others in the Analytica community aware of your successes or capabilities. Consultants may find this an opportunity for exposure to others with particular modeling needs. Also, if you are an Analytica aficionado, this is a great opportunity to help others.

If you would like to be a presenter, submit your proposed topic to webinars@lumina.com and possible presentation times (include the time zone). We will schedule the GotoMeeting conference (you do not need a gotoMeeting subscription yourself) and we will make you presenter during the session, allowing you to share your screen while you talk. You will most likely make use of Power Point and a running Analytica during your presentation.

Archive of Past Topics

Visit the Archive of Past Topics for abstracts, example models, and recordings of previous Analytica User Group webinars. Previous topics that have been presented include:

Graph Style Templates
Sneak preview of Analytica Web Publisher
Querying an OLAP server
Querying an ODBC relational database
Self-Indexes, Lists and Implicit Dimensions
Flattening and Unflattening of Arrays
Introduction to Arrays and Array Abstraction
Local Indexes
The Iterate Function
The Reference and Dereference Operators
Modeling Utility Tariffs in Analytica
Modeling Energy Efficiency in Large Data Centers
Calling External Applications
Introduction to Linear and Quadratic Programming
Non-Linear Optimization
Writing User-Defined Functions
Modeling Markov Processes in Analytica
Manipulating Dates in Analytica
Button Scripting
Using Regression
Creating Scatter Plots
Statistical Functions in Analytica 4.0
Manipulating Indexes and Arrays in Analytica Expressions
Edit Table Enhancements in Analytica 4.0
Handles and Meta-Inference

Potential future topics

If you would like to see a webinar on a given topic, please feel free to add it here. If you see a topic listed and would like to be a presenter, let us know.

Rapid review of features new to Analytica 4.0.

Importance Sampling. Global sample weighting and use of extended statistic functions in 4.0.

Topics in Regression: Using the Regression function in flexible ways, such as infering VARMA models, DFTs, etc. Estimating secondary statistics (i.e., uncertainty in the parameters) and modeling the full uncertainty in resulting model predictions (the RegressionDist function, etc).

Logistic Regression: Quick intro to logistic regression (generalized regression), including Probit_Regression, Logistic_Regression, Poisson_Regression, etc. Using these to fit probability estimates in Analyica, Analyica Optimizer experience, exploring result with new graphing features.

New 4.0 graphing features general overview

Creating graphs of multi-dimensional data.

An in-depth look at graph style settings.

Producing graphs from ADE: Including how to serve graphs from web pages.

Intracacies of the Domain attribute

Mastering Array Abstraction

Writing User-Defined Distribution functions.

Sampling and Distributions - new 4.0 additions/extensions. Also, writing custom User-Defined Distribution Functions.

Getting data into Analytica.

DetermTables

Implementing iterative algorithms. Convergence algorithms using Iterate. Use of While..Do. Recursive functions, slice assignment, etc.

Large-scale sampling. Techniques when memory limitations constrain sampleSize.

Creating User-Defined functions. Review of Function Parameter Qualifiers.

Understanding Evaluation Contexts

Bayesian Inference

Sensitivity Analysis.

Dynamic Programming

Approximate and Stochastic Dynamic Programming

Correlated and multi-dimensional distributions

Probability assessment -- how to estimate uncertainty and select distributions.

User Survey Results

During the first week of September, we sent out a survey to people who had attended webinars so far. Please continue providing us with feedback. Here is some feedback to date:

Level of difficult and speed:

So far, of those who answered this question, 25% say "a bit too easy", 25% say "too hard/fast", and 50% say "just right".

Topics requested for future webinars:

How to run multiple iterations, e.g. 100 iterations with uncertainty sample of 1000.

Sampling for rare events.

Using the lognormal function.

Financial modeling

New array functionality (subtables, choices in tables)

Optimizer !!!

Dynamic models (twice requested)

Choice of distributions

Re-sampling and radomize methods and uncertainty sample size

Tricks for sensitivity analysis

Input and output nodes

Importance analysis

The Analytica Wiki

The Analytica Wiki contains many resources, including in-depth reference materials, relevant articles, example models, tutorials, etc., to help users master Analytica and find what they need. Even better, Analytica users can contribute! You can upload your own models, articles, expand on or correct materials that are there, etc., for the benefit of the entire Analytica community.

The Analytica Forum

The Analytica Forum is a message board where users can post questions to the Analytica community, or view what others have posted. Many materials of general interest have been posted there (however, we hope to eventually update the Wiki to reflect all this material, where it can be more conveniently organized). The forum is maintained indepedently by an enthusiastic Analytica user. Our thanks to to Mike for all his efforts!