Difference between revisions of "Analytica User Group"

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The Analytica User Group provides a support system and various resources among existing Analytica Users.
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[[Category: Training]]
 +
[[Category: Videos]]
  
= Webinar Series =
+
[[/Past Topics|Past Topics]] >>
  
The Analytica webinar series uses GotoMeeting with conference calling technology as a media for regular presentations on topics of potential interest to the community of Analytica users and modelers. Webinars are interactive, with questions and tangents 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, please send an email to mailto:sales@lumina.com.
+
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.  
  
Topic scope includes:
+
== Webinar Series ==
* Introduction to new Analytica 4.0 features.
 
* How-to: How to utilize specific Analyica features.
 
* Case-studies: Presentation about successful applications.
 
* General modeling topics.  E.g., an introduction to XYZ theory, and modeling this in Analytica.
 
* Analytica training.
 
  
In the upcoming weeks, we expect to offer several webinars covering features new to Analyica 4.0.
+
Analytica User Webinars are a great way to learn about key Analytica features and modeling skills. They are live demos, using Citrix Gotowebinar, and VOIP or your telephone, at your choice. Questions, comments, and tangents are welcome.
  
Webinar presentations may last anywhere from 20 to 90 minutes, depending on the topic (an estimate of duration should be included with the topic).
+
There are webinars most weeks, usually on Thursdays at 10am PST (1pm EST). 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).
  
== Schedule of Upcoming Webinars ==
+
If you missed a User Webinar, don't despair. We usually records them, including audio and screensharing. So, you can replay them any time. See below for the full list.
  
=== Edit Table Enhancements in Analytica 4.0 ===
+
;Recent talks include:
 +
* [[/Past_Topics#Expression Assist|Expression Assist]] (9-Feb-2012)
 +
* [[/Past_Topics#The Analytica Cloud Player Style Library|The Analytica Cloud Player Style Library]] (31-Jan-2012)
 +
* [[/Past_Topics#Intro_to_Analytica_Cloud_Player|Intro to Analytica Cloud Player]] (26-Jan-2012)
 +
* [[/Past_Topics#New_Features_in_Analytica_4.4|New Features in Analytica 4.4]] (19-Jan-2012)
  
<b>Date and Time:</b> Thursday, July 26, 2007 at 10:00 - 11:00am Pacific Daylight Time
+
=== Schedule of Upcoming Webinars ===
  
<b>Presenter:</b> Lonnie Chrisman, Lumina Decision Systems
+
==== Linearizing Optimization Models ====
  
<b>Abstract</b>
+
==== [[Model building by mouse]] ====
  
In this webinar, I will demonstrate several new edit table functionalities in Analytica 4.0, including:
+
'''Date and Time:''' (TBD)
* Insert [[Choice]] drop-down controls in table cells.
 
* [[Table Splicing|Splicing]] tables based on computed indexes.
 
* Customizing the [[TableCellDefault|default cell value(s)]].
 
* Blank cells to catch entries that need to be filled in.
 
* [[SubTable]]s
 
* Using different number formats for each column.
 
  
This talk is oriented for model builders with Analytica model-building experience.
+
'''Presenter''': (TBD)
  
=== Manipulating Indexes and Arrays in Analytica Expressions ===
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'''Abstract'''
  
<b>Date and Time:</b> (TBA)
+
See Model building by mouse for the concept. The talk will also cover the TemplateInput and TemplateOutput attributes first introduced in 4.2 that make template modules possible, and thus expand the potential power and applicability of this modeling technique.
  
<b>Presenter:</b> Lonnie Chrisman, Lumina Decision Systems
+
==== Saving Memory: Controlling when results are (and are not) cached ====
  
<b>Abstract</b>
+
'''Date and Time:''' (TBD)
  
In this webinar, I will review many of the common operations applied to indexes and arrays from within Analytica expressions, with a particular emphasis on enhancements in this area that are new to Analytica 4.0.  I'll review the often used and very powerful [[Subscript]] and [[Slice]] operations, along with the [[Associative_vs._Positional_Indexing|duality of associational and positional indexing]].  I'll introduce newly introduced extensions for positional indexes, such as the @I, A[@I=n], and @[I=n] operations, and extensions that expose positional duals to various previously-existing associational array functions.  I will describe the distinction between index and value contexts in Analytica expressions, along with the distinction between a variable's index value, mid value and sample value, how these may differ ([[Self-Indexed Arrays]]), and how we may access each context-value explicitly.  I will also introduce slice assignment -- the ability to assign values to individual slices of an array within an algorithm.
+
'''Presenter:''' Lonnie Chrisman, Lumina Decision Systems
  
The content of this webinar is most appropriate for users with moderate to advanced Analyica model-building experience.
+
'''Abstract'''
  
=== Statistical Functions in Analytica 4.0 ===
+
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.
  
<b>Date and Time:</b> (TBA)
+
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. 
  
<b>Presenter:</b> Lonnie Chrisman, Lumina Decision Systems
+
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.
  
<b>Abstract</b>
+
In Analytica 64-bit, you are less likely to encounter the problem of running out of memory, but you still may encounter performance slowdown from huge memory utilization.  Some large models, requiring extensive memory resources, run smoothly even when requiring far more memory than there is RAM available, while other result in extensive ''thrashing'', taking very long to evaluate.  I've found that differentiating factor has to do with the size of individual arrays within the model.  Thrashing tends to occur when a single array consumes more than about 1/3 the available RAM, while if all arrays in the model remain small relative to available RAM, huge memory evaluations often run very smoothly. I'll relate these observations, and what that means with respect to sample size.
  
A statistical function is a function that process a data set containing many sample points, computing a "statistic" that summarizes the data.  Simple examples are [[Mean]] and [[Variance]], but more complex examples may return matrices or tables.  In this talk, I'll review statistical that are built into Analytica 4.0.  In Analytica 4.0, all built-in statistical functions can now be applied to historical data sets over an arbitrary index, as well as to uncertain samples (the Run index), eliminating the need for separate function libraries.  I will demonstrate this use, as well as several new statistical functions, e.g., [[Pdf]], [[Cdf]], [[Covariance]].  I will explain how the domain attribute should be utilized to indicate that numeric-valued data is discrete (such as integer counts, for example), and how various statistical functions (e.g., [[Frequency]], [[GetFract]], [[Pdf]], [[Cdf]], etc) make use of this information.  In the process, I'll demonstrate numerous examples using these functions, such things as inferring sample covariance or correlation matricies from data, quickly histogramming arbitrary data and using the coordinate index setting to plot it, or using a weighted [[Frequency]] for rapid aggregation.
+
This talk is appropriate for advanced Analytica modelers.
  
In addition, all statistical functions in Analytica 4.0 can compute weighted statistics, where each point is assigned a different weight.  I'll cover the basics of sample weighting, and demonstrate some simple examples of using this for computing a Bayesian posterior and for importance sampling from an extreme distribution.
 
  
=== Creating Scatter Plots ===
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==== The [[Dynamic]] Function and Dynamic Loops ====
  
<b>Date and Time:</b> (TBA)
+
'''Date and Time:''' (TBD)
  
<b>Presenter:</b> Lonnie Chrisman, Lumina Decision Systems
+
'''Presenter:''' Lonnie Chrisman, Lumina Decision Systems
  
<b>Abstract</b>
+
'''Abstract'''
  
This webinar focuses on utilizing graphing functionality new to Analytica 4.0, and specifically, functionality enabling the creative use of scatter plotsThe talk will focus primarily on techniques for simultaneously displaying many quantities on a single 2-D graph.  I'll discuss several methods in which multiple data sources (i.e., variable results) can be brought together for display in a single graph, including the use of result comparison, coordinate indexes, and external variables.  I'll describe the basic new graphing-role / filler-dimension structure for advanced graphing in Analytica 4.0, enabling multiple dimensions to be displayed on the horizontal and vertical axes, or as symbol shape, color, or symbol size, and how all these can be rapidly pivoted to quickly explore the underlying data.  I'll discuss how graph settings adapt to changes in pivot or result view (such as Mean, Pdf, Sample views).
+
The [[Dynamic]] function in Analytica 4.2 is a bit more flexible than previouslyIt is now possible for [[User-Defined Functions]] to be part of a dynamic loop, and there are cases where it is now possible to operate over the [[Time]] index where previous it was not.  I'll discuss how dynamic models are evaluated, and how that differs from non-dynamic models, and cover some tricks for tracing evaluation and debugging complex dynamic models (which can often be challenging to debug).  I'll also introduce how [[Dynamic]] can be used on an index other than the built-in [[Time]] index.
  
== How to Attend ==
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==== [[IntraTable]]s ====
  
To attend, you need to sign up by contacting Lumina at webinars@lumina.com or (650) 212-1212.  Attendence is limited to 10 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.
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'''Date and Time:''' (TBD)
  
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.
+
'''Presenter:''' Lonnie Chrisman, Lumina Decision Systems
  
== How to be a Presenter ==
+
'''Abstract'''
  
Being a presenter at an Analytica webinar provides an opportunity to make others in the Analytica community aware of your successes or capabilitiesConsultants may find this an opportunity for exposure to others with particular modeling needsAlso, if you are an Analytica aficionado, this is a great opportunity to help others.
+
An [[IntraTable]] is a variation of an edit [[Table]], where (like [[Table]]s), the cells may contain expressions, but unlike [[Table]]s, the expressions in each cell can refer to values of other cellsThis may (quite appropriately) conjure up nightmares of spreadsheet hell.  While this isn't something you'd want to use nonchalantly, there are cases when the ability to reference other cells within the same table comes with its benefitsBecause the [[IntraTable]] allows any pattern of references (it doesn't have to be strictly left-to-right, for example), as long as a cell-cycle isn't created, it is possible to encode certain recurrences that would otherwise be quite difficult to encode.
  
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.
+
=== How to Attend ===
  
== Potential future topics ==
+
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.
  
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.
+
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.
  
* Rapid review of features new to Analytica 4.0.
+
=== How to be a Presenter ===
  
* Importance SamplingGlobal sample weighting and use of extended statistic functions in 4.0.
+
Being a presenter at an Analytica webinar provides an opportunity to make others in the Analytica community aware of your successes or capabilitiesConsultants 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.
  
* 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)Alternative regression models ([[Probit_Regression]], [[Logistic_Regression]], [[Possion_Regression]], etc).
+
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 talkYou will most likely make use of Power Point and a running Analytica during your presentation.
  
* Logistic Regression: Quick intro to logistic regression (generalized regression), including [[Probit_Regression]], [[Logistic_Regression]], [[Possion_Regression]], etc.  Using these to fit probability estimates in Analyica, Analyica Optimizer experience, exploring result with new graphing features. 
+
===Analytica User Group:([[Analytica_User_Group/Past_Topics#The_Large_Sample_Library|Large Sample Library]])===
  
* New 4.0 graphing features general overview
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=== [[Analytica User Group/Past Topics|Archive of Past Topics]] ===
  
* Creating graphs of multi-dimensional data.
+
Visit the [[Analytica User Group/Past Topics|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: Creating libraries of style templates, including some behind-the-scenes settings.
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* Guidelines for Model Transparency
 +
* Automated Monitoring and Failure Detection
 +
* Principal Component Analysis (PCA)
 +
* Internal Rate of Return ([[IRR]]) and Modified Internal Rate of Return ([[MIRR]])
 +
* Bond Portfolio Analysis
 +
* Net Present Value ([[NPV]])
 +
* The Analytica Docs, and How to Contribute
 +
* Data Center Capacity Planning
 +
* Modeling the Precision Strike Process
 +
* The Performance Profiler
 +
* Variable Stiffness Cubic Splines
 +
* Introduction to [[DetermTable]]s
 +
* Importance Sampling (Bayesian posteriors)
 +
* Importance Sampling (rare events)
 +
* Statistical Functions
 +
* [[Table Splicing]]
 +
* Analytica Web Player
 +
* [[SubTable|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-Indexed Arrays|Self-Indexes]], Lists and [[Implicit Dimensions]]
 +
* Flattening and Unflattening of Arrays
 +
* Introduction to Arrays and Array Abstraction
 +
* [[Local Indexes]]
 +
* The [[Iterate]] Function
 +
* The [[Using_References|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
 +
* [[Handle]]s and [[Meta-Inference]]
  
* An in-depth look at graph style settings.   
+
=== Potential future topics ===
 +
 
 +
If you would like to see a webinar on a given topic, please feel free to add it hereIf you see a topic listed and would like to be a presenter, let us know.
  
* MdxQuery - Interacting with Microsoft Analysis Services or other OLAP servers.
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* Statistical hypothesis testing.
 +
** Standard textbook tests
 +
** Computing p-values using Monte Carlo for complex and non-standard statistical models.
  
* Producing graphs from ADE: Including how to serve graphs from web pages.
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* Time-series analysis
  
* Manipulating dates in Analytica
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* Using the interpolation functions, [[LinearInterp]], [[CubicInterp]], [[StepInterp]].
  
* Integrating with external programs:  Utilizing external programs or scripts (VBScript, Perl, etc) from within an Analytica model.
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* Numeric precision - numeric round-off, underflow, etc., why they happen, what to do about it.
  
* An introduction to button scripting in Analytica
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* Net Present Value and Internal Rate of Return -- introduction to the use of these commonly used metrics for quantifying decision quality.
  
* New extensions to the Analytica Optimizer
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* Using the ''Performance Profiler'' to understand where your model consumes time and memory resources.
  
* Introduction to Linear, Quadratic and Non-Linear Programming, and the basics of using Analytica Optimizer.
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* Producing graphs from ADE: Including how to serve graphs from web pages.
  
 
* Intracacies of the Domain attribute
 
* Intracacies of the Domain attribute
 
* Writing user-defined functions.  Understanding parameter qualifiers.  Introduction to new 4.0 qualifiers.  Writing distribution functions. Writing array abstractable functions.
 
  
 
* Mastering Array Abstraction
 
* Mastering Array Abstraction
  
* Sampling and Distributions - new 4.0 additions/extensions.  Also, writing custom User-Defined Distribution Functions.
+
* Writing User-Defined Distribution functions.
 
 
* Integrating with external applications using [[RunConsoleProcess].
 
 
 
* [[Handle]]s and [[Meta-Inference]].
 
 
 
* Using references (the \ and # operators)
 
  
 
* Getting data into Analytica.
 
* Getting data into Analytica.
  
 
* [[DetermTable]]s
 
* [[DetermTable]]s
 
* 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.
 
* Large-scale sampling.  Techniques when memory limitations constrain sampleSize.
Line 148: Line 189:
 
* Dynamic Programming
 
* Dynamic Programming
  
* Correlated and multi-dimensional distributions
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* 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:
 +
 
 +
<b>Level of difficult and speed:</b>
 +
 
 +
So far, of those who answered this question, 25% say "a bit too easy", 25% say "too hard/fast", and 50% say "just right". 
 +
 
 +
<b>Topics requested for future webinars:</b>
 +
 
 +
* 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
  
== Past Topics ==
+
* Tricks for sensitivity analysis
  
(none yet)
+
* Input and output nodes
  
= The Analytica Wiki =
+
* Importance analysis
  
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 Docs==
  
= The Analytica Forum =
+
The [[Analytica Docs]] 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 [http://revelarium.com/phpBB/index.php 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!
+
==See Also==
 +
* [[Tutorial videos]]

Latest revision as of 21:10, 7 August 2024


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

Analytica User Webinars are a great way to learn about key Analytica features and modeling skills. They are live demos, using Citrix Gotowebinar, and VOIP or your telephone, at your choice. Questions, comments, and tangents are welcome.

There are webinars most weeks, usually on Thursdays at 10am PST (1pm EST). 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).

If you missed a User Webinar, don't despair. We usually records them, including audio and screensharing. So, you can replay them any time. See below for the full list.

Recent talks include

Schedule of Upcoming Webinars

Linearizing Optimization Models

Model building by mouse

Date and Time: (TBD)

Presenter: (TBD)

Abstract

See Model building by mouse for the concept. The talk will also cover the TemplateInput and TemplateOutput attributes first introduced in 4.2 that make template modules possible, and thus expand the potential power and applicability of this modeling technique.

Saving Memory: 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.

In Analytica 64-bit, you are less likely to encounter the problem of running out of memory, but you still may encounter performance slowdown from huge memory utilization. Some large models, requiring extensive memory resources, run smoothly even when requiring far more memory than there is RAM available, while other result in extensive thrashing, taking very long to evaluate. I've found that differentiating factor has to do with the size of individual arrays within the model. Thrashing tends to occur when a single array consumes more than about 1/3 the available RAM, while if all arrays in the model remain small relative to available RAM, huge memory evaluations often run very smoothly. I'll relate these observations, and what that means with respect to sample size.

This talk is appropriate for advanced Analytica modelers.


The Dynamic Function and Dynamic Loops

Date and Time: (TBD)

Presenter: Lonnie Chrisman, Lumina Decision Systems

Abstract

The Dynamic function in Analytica 4.2 is a bit more flexible than previously. It is now possible for User-Defined Functions to be part of a dynamic loop, and there are cases where it is now possible to operate over the Time index where previous it was not. I'll discuss how dynamic models are evaluated, and how that differs from non-dynamic models, and cover some tricks for tracing evaluation and debugging complex dynamic models (which can often be challenging to debug). I'll also introduce how Dynamic can be used on an index other than the built-in Time index.

IntraTables

Date and Time: (TBD)

Presenter: Lonnie Chrisman, Lumina Decision Systems

Abstract

An IntraTable is a variation of an edit Table, where (like Tables), the cells may contain expressions, but unlike Tables, the expressions in each cell can refer to values of other cells. This may (quite appropriately) conjure up nightmares of spreadsheet hell. While this isn't something you'd want to use nonchalantly, there are cases when the ability to reference other cells within the same table comes with its benefits. Because the IntraTable allows any pattern of references (it doesn't have to be strictly left-to-right, for example), as long as a cell-cycle isn't created, it is possible to encode certain recurrences that would otherwise be quite difficult to encode.

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.

Analytica User Group:(Large Sample Library)

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
  • Principal Component Analysis (PCA)
  • Internal Rate of Return (IRR) and Modified Internal Rate of Return (MIRR)
  • Bond Portfolio Analysis
  • Net Present Value (NPV)
  • The Analytica Docs, 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
  • 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.
  • Large-scale sampling. Techniques when memory limitations constrain sampleSize.
  • 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 Docs

The Analytica Docs 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.

See Also

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