Mstat Software

Mstat was developed to help students analyze their data using nonparametric statistical methods. This program grew out of a graduate course, "Statistical Problems in Genetics and Molecular Biology," taught by the Department of Oncology at the University of Wisconsin-Madison over the last 20 years.

This site will have the latest version of the Mstat software package for Windows, Macintosh OSX, and Linux, available from the Download link above. Help for using Mstat is also available.

As in the past, the help files include a copy of the notes for the "Statistical Problems …" course mentioned above. These course notes have been made into a book. Both paperback and ebook versions are available, as detailed on the Help page.

Version 6 is coming

A major revision to Mstat will be available by Summer. Although there will be a handful of new features, the main focus for this rewrite is under the hood. The new version will have greatly improved consistency across platforms and will no longer require Java on the Mac and on Linux.

Mstat 5.5.7 released April, 2013

I've implemented significant improvements in the way that p-values are computed for the Wilcoxon rank sum (WRS) test. First, a much faster algorithm for computing the exact p-value allows doing so over a much increased range of group sizes, up to a total of 200 observations (100 per group). The first time an exact p-value is computed for two groups of 100 observations each, it will take about 8 seconds to do so. Subsequent calls to this function will only take a few milliseconds. This improved algorithm also allows larger sample sizes in the exact permutation test used for the case of multiple experiments, allowing, for example, two experiments with 25 observations per group. When ties are present, or the sample sizes are larger, an improved method is used to compute the approximate p-value, which is much more accurate than the standard Normal approximation at small p-values. For details, follow the link.

A bug that resulted in the failure to import the last row for some csv files has also been fixed.

Note that versions 5.5.5 and 5.5.6 were for testing purposes and not generally released.

Mstat 5.5.4 released February, 2012

A bug resulting in improper closure of the About dialog on OSX and Linux was fixed.

Mstat 5.5.3 released February, 2012

An error when installing on some Windows XP systems was fixed. A new Windows installer is available on the Download page. Windows 7, OSX, and Linux installations are not affected, but you should run Check for updates from the Help menu.

Mstat 5.5.2 released January, 2012

Minor fixes (see Version history). Use Help > Check for updates from the menu to install the new version.

Mstat 5.5.1 released January, 2012

Two new functions have been added for this release. Barnard's exact test provides a more powerful alternative to Fisher's exact test for analysis of 2×2 tables when either the row or column totals are fixed by design. This test was implemented as a plug-in in version 5.4. The Pairwise test menu choice provides a convenient shortcut to performing multiple two-sample tests, including the Wilcoxon rank sum test or the Spearman or Kendall rank correlation test, and computing Bonferroni corrected P-values as well as FDR q-values. See the Reference section of the Help file for more details.

Other changes in this release include alterations to the help system such that the help files are opened in the default browser on all platforms, improved font defaults for Windows 7, and a handful of minor bug fixes. Click on the Version History link in the banner for further details.