We are pleased to announce the release of version 3.1.0 of the popular SAS data analysis package SasView. Download from http://www.sasview.org/ Package installers are provided for Windows 32-bit and Mac OSX operating systems. Source code is provided for those who wish to build SasView on Unix/Linux operating systems. New in Version 3.1.0 * The documentation/help has had a complete overhaul including: * A completely new presentation interface (Sphinx). * Proof reading! * Updating for latest features. * A Help (or sometimes ?) button has been added to every panel, and some sub panels if appropriate, linking to the appropriate section in the documentation. * The model help has been split so that the Details button now brings up a very short pop-up giving the equation being used while HELP goes to the section in the full documentation describing the model. * Extensive help has also been added for the new optimizer engine (see below) including rules of thumb on how and when to choose a given optimizer and what the parameters do. * The optimizer engine has been completely replaced. The new optimizer still defaults to the standard Levenberg-Marquardt algorithm. However 4 other optimizers are now also available. Each starts with a set of default parameters which can be tuned. The DREAM optimizer takes the longest but is the most powerful and yields rich information including full parameter correlation and uncertainty plots. A results panel has been added to accommodate this. * The five new optimizers are: * A Levenberg-Marquardt optimizer * A Quasi-Newton BFGS optimizer * A Nelder-Mead Simplex optimizer * A Differential Evolution optimizer * A Monte Carlo optimizer (DREAM) * New models were added: * MicelleSphCoreModel (currently residing in the Uncategorized category) * Existing models were updated: * LamellarPS (bug in polydispersity integration fixed) * RectangularPrismModel * RectangularHollowPrismModel * RectangularHollowPrismInfThinWallsModel * A number of bugs were fixed including a thread crashing issue and an incorrect slit smearing resolution calculation. * Implemented much more robust error logging to enable much easier debugging in general but particularly the debugging of issues reported by SasView users. For further details and known issues, please see the release notes. We hope you like it! The SasView Development Team