SimPandemic Change Log

Post questions about using SimPandemic, including any suggestions for product updates

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SimPandemic Change Log

Post by KenHess »


On the Customize Settings page added a button to Reset to Defaults. This will reset all settings on all forms to the default values. If there is more than one Sandbox in the Notebook that you are using, this command only resets values in the Sandbox that you are currently using.

Also, on the Customize Settings page enabled the browser back button to work when navigating between forms on the page.

On the Population Statistics page added new fields to enable two Infection Events During the Simulation, in addition to the previously existing fields that specify individuals already infected at the beginning of the simulation.

On the Disease Characteristics page added a field to specify the Duration of Natural Immunity (years).

On the Vaccine page added a field to specify the Duration of Vaccine-induced Immunity (years).


Added Export to Excel option to the Sandbox that downloads an Excel-format file for the current simulation. In the first spreadsheet tab, the exported data includes daily values for: Population, Healthy, Infected, Symptomatic, Quarantined, Cumulative Immune, Hospitalized, Cumulative Dead, and Economic Output. The second spreadsheet tab includes the Summary Table from the Sandbox.

The FAQ describes how SimPandemic combines the effectiveness of different interventions using a naive dependency algorithm. In earlier versions of the simulator, this naive dependency algorithm operated on different interventions (e.g., social distancing applied at the same time as PPE) and also for the same intervention (e.g., social distancing) applied between different age groups (e.g., an adult simulant trying to infect an elderly simulant). In this version of the program, we no longer apply the naive dependency algorithm for the same intervention applied to different age groups. In most cases, the results will be little changed from earlier versions; however, if (for example) your strategy is to isolate the elderly with a higher social distancing effectiveness than other age groups, you will see fewer elderly being infected in this version.


Added the ability to compare different settings in the Sandbox. SimPandemic adds a new graph to the history each time that you change parameters in Customize Settings and press Run Simulation or when you press Re-run. Buttons under the Sandbox enable you to View Previous or View Next graphs in the history. You can only press Customize Settings or Re-run when you are viewing the most recent graph in the history. When you Save/Share your entire history will be saved or shared.


This version has a massive update of the user interface. We’ve embedded multiple instances of the simulator in a notebook-style interface that offers lots of guidance (a textual discussion that expands and collapses) along with the SimPandemic simulator. Some instances of the simulator are static, where you can examine the settings and hover over the graph, but you can’t modify the settings. There are also instances of the simulator that we call Sandboxes, where you can change any parameter just like the earlier version. Even for the Sandboxes we offer guidance on things to try that will reinforce the overall story created by the notebook.

Saved/shared simulations from earlier versions can be read by the new version. They will be loaded into a Sandbox that works the same as earlier versions.

Added COVID-19 Introduction notebook in the Library.

Added a zoom feature to all graphs that enables you to expand the y-axis.

Hovering over a graph (on desktop computers) or touching a graph on mobile devices reads out all variables at once instead of one at a time.

Customized Settings-Business Closure now has its own form. Previously, business closures were on the Social Distancing form.

Changes to some field labels to clarify what data to enter.

The FAQs have been dramatically expanded, and there is now a table of contents at the top of the FAQ page.

Modified the Hospitalized (% of capacity) calculation to provide more resolution of the pandemic's impact on hospitals.

Added a message for the rare (but real) case where the initially infected individual(s) fail to infect any others due to chance: "SimPandemic uses probabilities throughout every simulation. For this simulation, due to chance, your initial, infected individual(s) did not transmit the disease to anyone else. Press Re-run to try again!"

Fixed a bug with Social Distancing that incorrectly reduced its effectiveness in certain circumstances.

Fixed a bug with PPE mitigation that incorrectly applied its effect in certain circumstances.


Added Scenario: (New! 4/19/20) Runaway COVID-19 outbreak with 98% of cases asymptomatic
Added Scenario: (New! 4/19/20) Possible Solution #2A: Strong social distancing, followed by weak (except the elderly), followed by a vaccine

Changed label in Custom Settings – Disease Characteristics to Chance of Death (percentage of symptomatic cases). Previously, it did not say "of symptomatic cases." No change in the algorithm or functionality.

Cached Scenarios so that if a Scenario has ever been run before it will display almost instantly, without having to re-run the simulation. This makes the display of most Scenarios much faster. The user can force a re-run to evaluate variation between different runs by manually pressing Re-run on the output page.

Several "typos" were corrected on a rolling basis before this formal release.


Original product release.

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