Autumn 2008

Newsletter Home | Contact | GRC



GoldSim News


Featured GoldSim Application


Modeler's Corner


Tips and Tricks

  Interesting Links



Specifying Correlation Matrices Within GoldSim


Did you know that you can generate vectors of correlated stochastic histories with the History Generator element?   Simply change the element to a vector-type History Generator, then check the Use Correlation Matrix option.   This will enable the Edit Matrix button and allow you to specify a correlation matrix for the items in the vector.   This is an excellent tool for modeling demand, asset prices and other situations where variable movements over time are strongly correlated.  


While correlation matrices can only be specified for vector-type History Generator elements in GoldSim 9.60, they can be specified for both Stochastic elements and History Generators in Version 10. 


The Mystery of %en%1 Revealed!


Perhaps you've wondered what

%en%1 means for when you've edited the Header field in the Chart Styles dialog for a new GoldSim Result element.   It's actually one of a large number of GoldSim keywords that you can use in plot labels.  In this case it tells GoldSim to show the name of the element that calculated the first output selected for plotting.   In addition to the %en% keyword there are keywords for units, simulation settings (such as number of realizations and duration), and the date and time a simulation run was completed.   You'll find a complete description of keywords in the Using Keywords in Styles section of the User's Guide and Online Help.





Modeling and Simulation Definitions: Confused about a term?  This is a good collection of definitions and terms related to modeling and simulation.

Uncertainty: This Wikipedia article provides an overview on the concept of uncertainty, and how it is accounted for and quantified within various fields.


Autumn 2008 GoldSim Newsletter

The mission of the GoldSim Technology Group is to help you make better decisions in an uncertain world by providing state-of-the-art software, training and expert consulting. Our GoldSim simulation software package provides the power, flexibility, and usability to efficiently simulate and understand the future behavior of complex systems in business, engineering, and science.

Since this newsletter is for you, we encourage you to share your comments and contributions with us. Please email your thoughts to

GoldSim News

GoldSim Version 10 Beta Available for Download 

A Beta release of GoldSim Version 10 is now available from the GoldSim Resource Center (GRC). GoldSim Version 10 has a very large number of new features and enhancements, and all current GoldSim users are encouraged to give it a test drive.

The Beta version installs in parallel to your current version and shares your existing license, so you can experiment with the Beta while maintaining and using your current GoldSim version.

You can view a document summarizing the extensive changes included in Version 10 here.

to log into the GRC to download GoldSim Version 10 Beta

Save the Date: 2009 GoldSim User Conference

The 2009 GoldSim User Conference is moving back to our hometown, Seattle Washington on June 22-24, 2009.   The Conference will be held at the Hilton Seattle.   Monday, June 22 will be dedicated to a GoldSim training and refresher course.  The User Conference itself will follow on June 23 and 24.

The conference and training provides a terrific opportunity for you to share experiences with other users and the GoldSim developers, and to provide input for the future development of GoldSim. As always, we will schedule several social events in the evenings so you can enjoy the sights of one of the world's most beautiful cities while networking with fellow GoldSim users.

The program for the conference will include workshops and seminars to improve your GoldSim skills, presentation of a number of invited papers from our most experienced and knowledgeable users on topics of general interest, a poster session so you can see how other users are applying GoldSim, a model contest so you can show off your GoldSim skills (and learn from others), and several breakout sessions so users with common interests can share ideas

A detailed program and further information for reserving your spot will be provided before the end of the year.

Featured GoldSim Application

Using GoldSim to Simulate the Impact of California's Water Management Practices on Salmon Populations

The State of California wrestles with a number of complex water resource issues that affect humans and wildlife alike. As in any ecosystem, critical, and sometimes unexpected, cause-and-effect relationships exist.  It is imperative that California's water management strategies help sustain and recover its diverse fish populations. In order to model the impacts of California's myriad water management strategies on the state's salmon populations. Cramer Fish Sciences, a Sacramento fisheries and environmental consultancy, used GoldSim to develop a salmon life cycle model. The model forecasted how small changes in various water projects would affect the current and future salmon populations. The model identified the most viable, environmentally-friendly water management strategy for the State of California to implement. This article briefly discusses Cramer's modeling application.

 Modeler's Corner

Using Importance Sampling to Model High-Consequence, Low-Probability Outcomes

For risk analyses, it is frequently necessary to evaluate the low-probability, high-consequence end of the distribution of the performance of the system. Because the models for such systems are often complex (and hence need significant computer time to simulate), it can be difficult to use the conventional Monte Carlo approach to evaluate these low-probability, high-consequence outcomes, as this may require excessive numbers of realizations.

To facilitate these type of analyses, GoldSim allows you to utilize an importance sampling algorithm to modify the conventional Monte Carlo approach so that the tails of distributions (which could correspond to high-consequence, low-probability outcomes) are sampled with an enhanced frequency.


As always, we encourage user requests and suggestions. If you have specific feedback, please contact us at . You can unsubscribe or subscribe to this Newsletter at our website. 2008 GoldSim Technology Group LLC.