Macaulay2 code

On this page, I maintain links to some Macaulay2 software I have (co-)written or been substantially involved in writing.

• NonPrincipalTestIdeals.m2 — A package for computing the test ideals and F-pure thresholds of non-principal ideals. Builds on the TestIdeals package below.
• KHClosure.m2 — A package for computing the KH closure (and related closures) as described in this paper.
• LazyPowerSeries.m2 — A package for working with arbitrary-precision power series (including those whose coefficients are given by functions) in Macaulay2. The necessary subfiles, related code, and documentation can be found here.
• RationalMaps.m2 — A package for studying rational maps between projective varieties. Some documentation is available here.
• Seminormalization.m2 — A package for seminormalizing rings and varieties. Some documentation is Preprint.
• Pullback.m2 — A package for pulling back in the category of rings and thus constructing non-normal rings and varieties.
• Divisor.m2 — A package for working with Weil divisors on affine and projective varieties. Some documentation is here Published paper.

TestIdeals and FThresholds (+ PosChar)

• TestIdeals.m2 — The link to the development version of the TestIdeals.m2 package. To download the package in one file, source code (for use in Habanero).
• FThresholds.m2 — The link to the development version of the FThresholds package. To download the package in one file, source code (for use in Habanero).
• Paper documenting TestIdeals.m2.
• Slides describing TestIdeals.m2.
• PosChar.m2 — An early version of the package for doing computations of F-singularities within Macaulay2 (updated June 10 2014). Here is some (slightly outdated) additional documentation in PDF format. Joint work with Daniel Hernández, Moty Katzman, Sara Malec, Pedro Teixeira and Emily Witt.

Here are some smaller projects which have since been included in TestIdeals/FThresholds.

• Finj.m2 — Code for computing whether a given ring is F-injective (currently it requires the ring to be graded). This was written with Anurag K. Singh.
• FSplitting.m2 — Code for computing the compatibly Frobenius split subvarieties of a given variety. Joint work with Moty Katzman.