Author Archives: Andrew

The SolverStudio_00_04_06_22 release focusses on improvements for AMPL, the main one being a menu item to display the data file in an Excel task pane. (This feature is also available for GMPL.) The displayed file is updated each time the model is run. The examples have been further improved, and should work by default using the free student version of AMPL. A print command has also been added to print models and their output.

The latest version of SolverStudio (2012.08.27) is now available for testing. This has numerous fixes and improvements, including better AMPL support, a fix for a bug that could erase your model, and speed improvements when writing data back to a sheet. The examples have been improved and extended. Thanks to my Engineering Science students for their feedback, and to Stu Mitchell for his testing with PuLP. All feedback welcome.

The latest SolverStudio release, most significantly, adds a Cancel button that appears only when solving large models. During a long run, it is now possible to minimise Excel (although you may have to Alt-Tab to bring it back as the task bar sometimes fails). Other smaller changes are included, such as making default values for indexed parameters work in CPython, adding an Uninstall button in the About box, and adding a Python example where we plot the cost as a constraint right hand side is changed. As usual, all feedback is welcome (particularly on the Cancel button). Andrew

SolverStudio version 00_04_01_14 (2011.01.16) fixes a missing DLL problem that resulted in a Python error (missing module “re”).

An issue regarding Python encodings has been reported when using CPython (termed “Python (external)” by SolverStudio); this is still being investigated, and may occur on non-English systems. Any further reports of this would be appreciated.

This version is a new upload replacing SolverStudio_00_04_01_12 20120108.zip, which was corrupted during the upload. Sorry about that. Andrew

The latest version of SolverStudio has been uploaded, and now features support for PuLP, AMPL (either a licensed version, or a student version downloaded by the user using SolverStudio), the GNU Math Programming Language GMPL (an AMPL look-alike, included with SolverStudio), GAMS (which must be installed by the user), and any Python code that works either under IronPython or the more standard Python (known as CPython), which is now included with the SolverStudio download. All feedback welcome.

Andrew

PS: Thanks for feedback from Max and Tom which has improved this version, and to Stu Mitchell for improving PuLP to work around limitations in IronPython. (This arose due to operator overloading which meant sorting doesn’t work in IronPython, but does work in standard Python.)

PPS: This download is somewhat larger as it includes a full CPython and the Gnu Linear Programming Kit (GLPK).