Release Notes for Stella 1.4.2

These release notes list feature changes for the current release of Stella Architect, iThink Version 1.4, Stella Professional, and Stella Designer. Feature changes are also shown for previous versions of the software. There is a list of Known Issues for the current software release as well as a version by version detailing of Defects Fixed.

New and Updated Features

In 1.4.2

Graph and Table Pad Labels

You can now rename the graph and table pads that show when the graph or table is minimized. Editing works just as it does for variable names.

Annotation Button for Variables

You can now use the annotation button to display a variable's documentation, equations and units of measure. See Annotation Button (Interface) for more details.

Graphical Panel

The units of measure now appear in the graphical panel - making it easier to there are units issues with graphical functions. Also, if the equation for a graphical has an error the panel will open on the equation instead of the graph.

Interface Page Resizing

When setting interface page size, existing content may restrict how much it can be adjusted. If a page has content that would be outside the page on resizing you will not get a message indicating the reason the page size was not able to be changed as requested.

In 1.4.1

Loop Label

A new Loop Label object has been added to the mode editing toolbar. This allows you to label loops and will highlight the links in the loop when the mouse passes over it. See Loop Labels (Model) for more information.

Navigation on the Model

A new navigation button has been added to the model to allow position changes to predefined locations or variables. These can be useful as shorcuts for navigating through large models. See Navigation Button (Model) for more details.

New Builtins

Use NAN to set a variable value so it will not appear on graphs. Use CLOCKTIME to return the current time on the computer the software is running on.

Graphics Frames on Interface

There is now an option to fit the graphics content to the frame. See Graphics Properties for more detail.

In 1.4

Multiplayer Gaming

In addition to publishing model interfaces, you can now create multiplayer games in which players connect from their own browsers, make decisions, and indicate their readiness to proceed. The model then uses decisions from all of the players as inputs for the next step in the game. Multiplayer games can be published to the isee Exchange under the Creative Commons license, with some limitations on model size. See Multiplayer Games for more details.

SVG Based Animations

It is now possible to create sophisticated animations based on SVG graphics files. These animations can include color, size, and rotation. See Animation Object(Interface) for more details.

Conditional Actions on Buttons

When you add a button to your interface, you can now set conditions under which each of the actions will be executed. This is especially useful in multiplayer games. See Button (Interface) for more detail.

Resizable Interfaces

Published interfaces can now be made resizable, allowing them to work well on a variety of devices. For details, see Resizable Interfaces.

Data Collection

You can now collect data on the use of your published simulation, including the results from different users and the time spent on different pages. Data collection is available through an isee Exchange subscription. There are several reporting options available for analyzing the data. For more details, see Data Collection.

Array Expressions

The modeling language has been extended to allow the use of expressions inside of the array functions (such as SUM(a*b)) to take an inner product. An inner product operator has also been added for 1 and 2 dimensional arrays. See Working with Arrays and especially Specialized Array Manipulation for more discussion.

Multiple Page Graphs, Tables, and Inputs (Interface Only)

There are new options for navigating through multiple pages of graphs, tables, and input devices. Rather than the standard and buttons, you can use tabs for each page, or a dropdown list including all pages. This is applicable to graphs, tables, group inputs, and arrayed inputs, and is selectable from the properties panel for each. See Pages Styles for details.

Connecting Modules

When you connect a variable to a module, or a module to a variable, you will see a menu item allowing you to select which variable within the module to connect. This will appear only if there is something marked as an input or output within the module that has not yet been connected.

Using Initial Equations with Graphical Functions

We have made a behavior change when you are using a separate initialization equation for a graphical function variable. Previously, the I equation would determine the value of the variable. Now the I equation determines the input into the graphical function.

Initialization and Graphs

Graphs will now use the initial values computed in the background. For bar graphs and pie charts, this means they will be populated with initial values before and after running an output restore. Regular graphs will not draw, but they will have a scale. This is true for models and interfaces, including published interfaces. Note that changing a controlled value will no longer generate a new initialization. See known issues for more discussion.

Stella Live Behavior

We have adjusted Stella Live to be less sluggish on larger models, and also to give visual cues when the model is in the process of computing. In particular, as you dial a knob, while the software is computing the graphs, over model elements will be displayed in gray instead of red. This indicates that the graphs are potentially out of date relative to the value showing for the knob.