Archived News 2007
Vensim Version 5.7 Released
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5.7 Changes
Unchangeable Constants have been added. These behave exactly the same as Constants, but can’t be changed when setting up a simulation. They are useful for preventing sliders in SyntheSim, reducing the number of things that a model user can change, and working with the VECTOR SELECT function. Unchangeable Constants are defined by a double equal sign ==. Models using Unchangeable Constants will not work in version of Vensim prior to 5.7. See "Variables" in Chapter 2 of the Reference Manual for more details.
Professional and DSS only: A new function VECTOR SELECT has been added. This function can sometimes be used in place of the PROD, SUM, VMAX and VMIN functions to improve Causal Tracing and speed simulation. See Chapter 4 of the Reference Manual for details.
Professional and DSS only: The optimizer has been substantially modified to increase efficiency and provide more direct control of convergence. The interpretation of the fractional tolerance specified has been changed somewhat to accomplish this. See Chapter 10 of the Reference Manual for more details.
DLL only: vensim_get_data when called with 0 as the final argument will return the exact number of data points required and not the maximum required for any variable.
Bug Fixes
PLE Only: Models created with hidden variables when opened in Vensim PLE would not display the hidden variables but only the arrows.
Published model packages with international characters in the filename, or the path the file was contained in, were not opening.
Reader Only: Venapps opening a run control dialog were not listing the loaded runs.
Importing spreadsheets saved in early Excel formats was not properly converting international characters.
Text in WingDings and other nonstandard fonts was being rendered in the Latin1 character set.
During optimization and sensitivity simulation memory usage was increasing unnecessarily.
Units checking on MIN, MAX and some other functions was sensitive to the order of arguments when one argument was a number.
Variables graphed from Gaming runs would sometimes display anomalous points.
Exported table values when time was running down did not paste correctly into Excel.
Vensim Version 5.6d Released
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5.6d Changes
Bug Fixes
Publishing models was creating a model marked as an application so that the package could only be opened in Vensim DSS.
5.6c Changes
Help files are now provided as .chm files for compatibility with Windows Vista. Because of this the help system will no longer work with Windows 95.
Pro/DSS Only: The files created during optimization with sensitivity, multiple start or vector searches are now named the same as the run name followed by _searchtype. For example instead of vector.dat the file will be called runname_vector.dat. Similarly instead of sensitiv.tab the file will be called runname_sensitive.tab (notice the e is now in place). Also if you are creating reports with a payoff the prediction error report files are called runname_1step.err and so on.
Pro/DSS Only: A new function called VECTOR LOOKUP has been added. This function takes a subscripted variable as the specification of the Y values and specifies a range for the X axis. The input variable can be constant or dynamic allowing more flexibility in specifying multidimensional, partially analytical and other specialized functional forms.
The File Publishing dialog now has buttons to save and load publication information. If you are publishing with setting different from the defaults it may be more convenient to save the settings, and then reload them each time instead of making the changes on the dialog. In conjunction with this there is now a Venapp command FILE>PUBLISH that creates a published model or application using a form file.
Exporting datasets now has an option to select the character encoding for the exported files. The default encoding is Unicode UTF8, but you may want to select another. Many versions of Excel will not work with this and it is better to use ANSII Standard (referred to as Windows (ANSI) by Excel). For excel file format output this is the default. Note that if you are only using regular Latin letters (A-Z, a-z) numbers and punctuation these settings do not matter. It is only for international (from this writer’s perspective) characters that it is important. DSS Only the MENU>VDF2TAB, VDF2DAT and VDF2XLS functions have had a character encoding argument added.
Parallel to exporting when you import a dataset that has international characters, you will be queried for the source encoding. This is applicable only to text, not for importing spreadsheets. DSS Only the MENU>DAT2VDF and TAB2VDF have had an encoding argument added.
Pro/DSS Only: The default analysis toolset that is built in has been changed to be the same as the old default2 toolset. If you have not modified your toolset the appearance will be slightly different as more tools will be available.
Bug Fixes
PLE/PLE Plus Only: Selecting type Reality Check was not working in the equation editor.
Delete from model with multiple variables could sometimes cause internal data corruption.
DSS Only: Using ODBC with a VARID during output would cause Vensim to close.
DSS Only: Variables requiring quotes were not recognized in SLIDEVAR and other controls. These variables should have the quotes around them escaped as in
SLIDEVAR,"\"simple.constant\"",15,8,15,7,,0|100|1,"",
Pro/DSS Only: If a vector search was interrupted during optimization the file vector.dat would not be available till Vensim was closed (note that this file has also been renamed now).
DSS Only: The TEST command was not properly evaluating model values in Venapps.
Bar graphs that were made very small had bars that would disappear.
Selecting variables with embedded brackets [] would sometimes fail to quote the names properly.
Saving of a model under Windows 95/98 would fail with a message about unable to create backup.
Copying text from tool output would add extra empty lines when pasting.
Non Latin upper and lower case characters were not being properly recognized. This meant a model could have both the variable åb and Åb. Those two should, and now will be, treated as the same so there may be some correction required if you created variables differing only by capitalization.
Exporting simulation results to Excel format files would results in garbled international characters.
Vensim Version 5.6b Released
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5.6b Changes
Tools and Selected Variables
Options have been added to a number of tools to work not only on the current workbench variable, but also on sets of variables. The Graph tools can be configured to operate on the workbench variable, or on the variables selected in the current view making it easy to quickly graph multiple variables. The Strip Graph, Table, Document, Stats and Sensitivity Graph tools can now all be configured to operate on currently selected variables, all variables in a view or all variables in the model.
When a tool is configured to operate on the selected sketch variables it will operate on the workbench variable if there are no selected variable, or if the text editor is opened on the model. This makes this selection convenient for working with the classical workbench variable, or for working with a selection of variables. For example, if you want to make a graph of several variables simply highlight them and click on the Graph tool. The variables will appear in a single graph. If you then want to single out a variable select it into the workbench, and click on the graph tool again.
For Vensim PLE and PLE Plus the Graph tool, both Table tools and, for PLE Plus, both Sensitivity graph tools have been configured to operate this way.
For the other configurations the default toolsets have been configured to operate this way but any existing toolsets will need to be modified to change their behaviour. For the Document tool these options have been added under the multiple equation settings. For the Graph tool there is a checkbox near the bottom to operate on "Selected Vars." For the Strip Graph, Table, Stats and Sensitivity Graph tools the old "Causes, Uses, None" choices at the top have been replaced with a dropdown list containing – None, Causes, Uses, Selected Vars, Current View and All Vars. If you select Current View and open the Text Editor instead of the Sketch Editor the tool will behave as if None were selected. Similarly, with Selected Vars if there is no selection the behaviour will be the same as if None were selected.
These changes make it easy to quickly operate on a group of variables, without getting in the way of doing causal tracing.
Templates and Autocentre/Fit to Screen
Every view using a template will open with the upper left hand corner in a fixed position. This will be true independent of your page mark settings. While the zoom percentage from the last time you had the view open will be retained, if zoom is set to "Fit to Screen" the sketch will not be centred. This should make it much easier to get consistent navigation effects using templates. The font used in template objects has also been set up to refer back to the template view, not the current view.
Bug Fixes
International characters were not going into the clipboard properly. This was especially noticeable when pasting to Excel.
Printing of models containing international characters was not working correctly.
Models stored in directories containing international characters were not saving correctly.
Excel file names with international characters were not opening properly for GET XLS … functions.
Increments on sliders in SyntheSim mode were being set to very small numbers when blank.
DSS/DLL only – vensim_get_varnames when asked for gaming variables was missing some where only a subset of subscripts were defined as gaming variables.
Some cells with text created from formula in spreadsheets were being ignored when importing the spreadsheet data.
Named ranges ending in numbers were not properly recognized when using GET XLS… functions.
Changing the range on a slider in SyntheSim was not properly updating the slide position.
New variable names were not showing up properly on the variable list when that was set to be visible.
Macro Variables could not be selected into the workbench form the Variable Selection Tab of the Control Panel.
Macro variables using subscripts different from those on the LHS of the calling equation were not working properly for element by element equation ordering required to resolve symbolic simultaneities.
Level equations that included non-standard subscripts were sometimes being updated automatically when a new cause is added or removed in the diagram.
When multiple subscript definitions define the same subscript range the last definition alphabetically that does not have a map will be used to name the family.
Custom bar graphs created using subscript ranges in the names of the variables to be displayed.
Trees showing polarities or link colours were not working when the link was to a valve.
5.6a Changes
Version 5.6a contains a number of bug fixes.
Bug Fixes
File permission problems could cause errors during simulation or when saving a model.
Models would print with variable names squished together.
Translation of models to UTF8 format could cause anomalous shadow variables to appear.
In the Model Reader the up and down arrow keys were not changing hide levels.
In the Model Reader Venapp’s with SyntheSim active were not updating.
Vensim was not running under Windows 98 or ME. Note that Vensim will not run under Windows 95.
Importing data from Excel files would sometimes cause unexpected behaviour.
Graphs with legends suppressed did not have sufficient bottom margins or display units when only 1 scale was used.
Venapp Only: READUNCHG and READCIN did not force a new simulation in SyntheSim mode.
Loading a model with SyntheSim active would cause an error. Repeatedly simulating without leaving a screen could cause buttons to not respond.
New Vensim Workshop dates have been released, for November 2006.