Past Topics >>

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

Getting Started with 4.2: New Licensing Models, Installation, Beta Testing

Date and Time: (TBD)

Presenter: Lonnie Chrisman, Lumina Decision Systems

Abstract

Analytica (and ADE) 4.2 are now in beta testing, and will be for a few months. Existing users with active support are welcomed to beta test. This webinar will be the starting point for a series of upcoming webinars on new Analytica 4.2 features, with the purpose being to let you know what you need to know to get up and running as an Analytica 4.2 beta tester.

During this webinar, I'll walk through the installation process with several different (and new) licensing scenarios. In addition to individual licenses (as we've always offered), Analytica 4.2 introduces centrally managed named-user and floating license options. I'll describe what these mean to you and their advantages. The beta testing period will give you an opportunity to test drive these license types. I'll step through the installation of both the license manager server and Analytica itself, and demonstrate some simple aspects of administering centrally managed licenses. I'll also brief show how to roam a license.

A series of follow-on webinars will cover new enhancements in Analytica 4.2.

Controlling when results are (and are not) cached

Date and Time: (TBD)

Presenter: Lonnie Chrisman, Lumina Decision Systems

Abstract

When a variable is computed, Analytica caches the result (i.e., keeps a copy around) so that when the same result is needed later, it does not need to be recomputed. Large array-valued results can end up consuming large amounts of memory, and lead to annoyances such as running out of available memory. There are instances where it isn't really necessary to cache a result -- either it will never be needed a second time, or it isn't a big deal to recompute it, or it is an exact copy of its parent (perhaps because only the result graph settings are different), so that by configuring that variable to not cache its result, or to release its cache as soon as all its children are computed, memory space can be recovered, perhaps allowing larger simulations to be conducted.

Analytica 4.2 introduces a new feature allowing you to configure when results are (or are not) cached. I'll demonstrate how to utilize this feature, and discuss limitations, such as situations where it would be a very bad idea not to cache.

If time allows (it probably will), I'll also throw in two other small memory-related controls new in 4.2. The WhatIf-style functions (WhatIf, WhatIfAll, Dydx, Elasticity, NlpDefine), i.e., functions that compute hypotheticals, have been modified in 4.2 to preserve previously computed values of other variables. This is a nice feature, but can impact tight-memory cases. I'll explain this change and how to avoid the extra memory consumption where appropriate. Second, I'll also show how Analytica's maximum working set size can be configured (on some operating systems), which can be used to keep other applications on your computer highly responsive even when large memory-intensive computations are churning away.

This talk is appropriate for advanced Analytica modelers.

Local Variables

Date and Time: (TBD)

Presenter: Lonnie Chrisman, Lumina Decision Systems

Abstract

I'll explain distinctions between different types of local variables that can be used within expressions. These distinctions are of primary interest for people implementing Meta-Inference algorithms, since they have a lot to do with how Handles are treated. Analytica 4.2 introduces some new distinctions to the types of local variables, designed to make the behavior of local variables cleaner and more understandable. One type of local variable is the LocalAlias, in which the local variable identifier serves as an alias to another existing object. In contrast, there is the MetaVar, which may hold a Handle to another object, but does not act as an alias. The only local variable option, declared using Var..Do, that existed previously is a hybrid of these two, which leads to confusion when manipulating handles. Since LocalAlias..Do and MetaVar..Do have very clean semantics, the use of these when writing Meta-Inference algorithm should help to reduce that confusion considerably. Inside a User-Defined Function, parameters are also instances of local variables, and depending on how they are declared, may behave as a MetaVar or LocalAlias, so I'll discuss how these fit into the picture, as well as local indexes and local indexes.

This is appropriate for advanced Analytica modelers.

Large Scale Sampling Library

Date and Time:

Presenter: Max Henrion, Lumina Decision Systems

Abstract

The large-scale sampling library provides a functionality to evaluate selected output nodes in small batches, making it possible to run large scale Monte Carlo simulations that otherwise would not fit in available RAM.

This presentation introduces this library and how to use it.

How to Attend

To attend, you need to sign up by contacting Lumina at mailto:webinars@lumina.com. Please sign up at least a day prior. Attendance is limited, so please don't sign up unless you sincerely intend to attend.

These Webinars are FREE to users who have an up-to-date Support for Analytica. If you are unsure, check with mailto:sales@lumina. For those without current support, the fee is US$50.

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:

Guidelines for Model Transparency
Automated Monitoring and Failure Detection
Principle Component Analysis (PCA)
Internal Rate of Return (IRR) and Modified Internal Rate of Return (MIRR)
Bond Portfolio Analysis
Net Present Value (NPV)
The Analytica Wiki, and How to Contribute
Data Center Capacity Planning
Modeling the Precision Strike Process
The Performance Profiler
Variable Stiffness Cubic Splines
Introduction to DetermTables
Importance Sampling (Bayesian posteriors)
Importance Sampling (rare events)
Statistical Functions
Table Splicing
Analytica Web Player
SubTables
Creating Custom Distribution Functions
Using the Check attribute to validate inputs and results
The Dynamic Function
Logistic Regression
Creating Control Panels
Statistical Functions
Creating Scatter Plots
Using Regression
New Functions for Reading Directly from an Excel File
Advanced Tornado Charts -- when inputs are Array-Valued
Using the Analytica Decision Engine (ADE) from ASP.NET
OLE Linking
Tornado Charts
Correlated and Multivariate Distributions
Assessment of Probability Distributions
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
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.

Statistical hypothesis testing.
- Standard textbook tests
- Computing p-values using Monte Carlo for complex and non-standard statistical models.

Time-series analysis

Using the interpolation functions, LinearInterp, CubicInterp, StepInterp.

Numeric precision - numeric round-off, underflow, etc., why they happen, what to do about it.

Net Present Value and Internal Rate of Return -- introduction to the use of these commonly used metrics for quantifying decision quality.

Using the Performance Profiler to understand where your model consumes time and memory resources.

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.

Getting data into Analytica.

DetermTables

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

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.