Winter 2011

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GoldSim News


Modeler's Corner


What's Cooking


Tips and Tricks


Model Library


Knowledge Base




Increase the Number of Realizations to Process Per Slave Transaction for DP Run:
If you are running a Monte Carlo simulation over a network using the DP Module, you may be able to more effectively reduce the run time by increasing the number of realizations to process per slave transaction (rather than increasing the number of slaves). This is especially true for models with a large number of realizations where each one takes a relatively short time to run. Read more in a Knowledge Base article.



The GoldSim Model Library allows GoldSim users to build on the experience and knowledge of others by sharing models. The Library is available within the GoldSim Wiki.

New models that have recently been added include:

Lake Biogeochemical Food Web Model: This is a nutrients, phytoplankton, and zooplankton model with dissolved oxygen dynamics for a vertically stratified lake system with river inputs.

Pumped Flow with Pump Curve:This model calculates flow rate through a pump given a pump operating curve and required head upstream of the pump.

Time Varying Water Demand:This simple model defines water usage patterns and applies them to a base demand rate to simulate time-varying demands for a water system.

Hydropower Revenue Optimization: This model demonstrates the optimization tools in GoldSim using a simple reservoir and hydropower model.

If you have a model that you think would be worth sharing, please post it to the Model Library on the GoldSim Wiki.



The GoldSim Knowledge Base contains articles addressing frequently asked questions, workarounds for known problems, and advice on applying GoldSim. The Knowledge Base is available within the GoldSim Wiki.

New articles that have recently been added include:

Microsoft Visual C++ Express - A Free Compiler/Debugger for DLLs to Run in GoldSim: How do I get started with a free C/C++ compiler for GoldSim DLLs and how do I debug GoldSim DLLs?

Adding a Database Source on a 64-bit System: I attempted to add a database source using the ODBC Data Source Administrator tool on a 64-bit system, but I was presented with an error message saying that ODBC driver could not be found.


Winter 2011 GoldSim Newsletter


GoldSim's mission 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 or post your comments in our Forums.


GoldSim News

GoldSim 10.5 Released!

GoldSim Technology Group released a new major version of GoldSim, GoldSim 10.5 on December 21, 2010. This version includes a significant number of new features and user interface improvements.

  • A major new feature, the Script Element has been added. Iterative calculations, complex array manipulations, and other highly customized calculations, many of which could only have been previously done using an External (DLL) element, can now be built directly into GoldSim as a procedural Script without any external programming.

  • GoldSim 10.5 includes another new element, the Aquifer Pathway for the CT/RT Module. An Aquifer pathway combines the features of a Cell and a Pipe element, and provides a way to simulate processes such as vertical transport through an unsaturated (vadose) zone, and horizontal transport in aquifers, rivers, channels and pipelines.

  • Date/time simulations can now extend over a much broader range: 1 January 1700 to 31 December 9999. GoldSim 10.5 also includes other enhancements for plotting time history results involving dates.

  • When editing an input field, GoldSim automatically suggests the names of existing outputs at the bottom of the input field.

  • GoldSim 10.5 supports the extended worksheet ranges (1,048,576 rows by 16,384 columns) introduced in Excel 2007.

  • If statements can handle mixtures of arrays and scalars.

  • The Time Series elements now include a new representation: Changes and constant values over the previous interval. These options make it easier to import measured time series data, as that is the manner in which it is often actually recorded (i.e., a change or an average value over the previous time interval).

  • The GoldSim Units Manager has been redesigned.

  • Lookup Tables now support an option to be linked to a text file. The text file data is imported automatically whenever the data in the file is modified.

  • GoldSim 10.5 provides powerful tools for both exploring and manually changing the causality sequence.

There are also many less visible changes and a number of bug fixes included in GoldSim 10.5. A description of the important changes can be found in the Summary Document.

All current members of the GoldSim Subscription Program can download the GoldSim 10.5 installation file from the Download section of our website.


Join Us in Upcoming GoldSim Webinars

Introduction to GoldSim 10.5

We invite you to an Introduction to GoldSim Version 10.5 webinar on 20 January, 2010 at 8AM and 4PM PST(-8 hours GMT). We will discuss the major new features in GoldSim 10.5. This webinar will give you a quick overview and discuss their potential applications so that you can start taking advantages of these new features.

Click here to register for the webinar and to receive an invitation.

Webinars for Water and Environmental Engineers and Planners

We are planning on having a series of webinars for water and environmental engineers and planners, once a month starting in January.

The fist webinar, held in January 27th, 2011 at 8AM and 4PM PST(-8 hours GMT), will introduce scripting inside a GoldSim model using a pumping head calculation example. In the example, the flow rate and the total dynamic head are calculated simultaneously using a bisection solver in a Script element. The pumped flow rate is based on the manufacturer's pump performance curve.

You may take a look at a list of upcoming Webinars. To register, please fill out and submit a webinars registration form.


GoldSim is Hiring

Working for the GoldSim Technology Group offers the excitement and challenge of working for a small company that is stable, successful, and has a growing customer and client base. Our culture rewards exceptional individuals who work well with others, who seek out responsibility and personal accountability, and who are comfortable with lively debate on topics ranging from software design to marketing strategies.

GoldSim currently has the following positions open:

  • Software Support Engineer
  • Scientific Programmer/Analyst
  • Senior Windows Application Developer

Visit our Jobs Page to learn more.


GoldSim has Moved

GoldSim Technology Group moved to a new office at the end of 2010. Our new address is:

GoldSim Technology Group LLC
22500 SE 64th Place, Suite 240
Issaquah, Washington 98027-8111

Our telephone numbers remain unchanged. Visit our website for more details.


Modeler's Corner

Examples of GoldSim's New Script Element

GoldSim’s new Script element provides a user friendly alternative to programming DLLs for highly customized calculations, such as iterative loops and working with arrays. This article introduces the Script element and goes through the Script element examples that are distributed with GoldSim 10.5, including an example of iterative calculations (Newton’s method) and an example of working with matrices to calculate a correlation matrix. The end of the article links you to two new models in the Model Library that use the Script element in water resources applications.



What's Cooking

Polls on GoldSim User Conference in Fall 2011

GoldSim Technology Group is considering hosting another GoldSim User Conference in Fall 2011. Are you interested in joining us at the Conference? If so, where do you think it should be held? Vote for a location in the GoldSim Forum.


Suggestions for GoldSim's Future Versions

We are currently deciding on features to be included in the next version of GoldSim. Now is your chance to contribute ideas on how GoldSim can be improved. Post comments and feedback on GoldSim in our Forums.



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