Monthly Archives: August 2007

Travis Oliphant Begins at Enthought

We’re pleased to announce that Travis Oliphant joins Enthought this week in the position of Vice President. Travis is well-known to the SciPy community as the architect of NumPy and author of the definitive guide to NumPy.

When Eric Jones and I started Enthought, Travis was on our short list of people we’d love to work with; circumstances have finally come together to make that happen. Travis will be working on various client projects and, of course, continuing to support SciPy. We expect to accomplish some amazing things with Travis on board.

Adding another “Travis” to Enthought will, most likely, foster some confusion, so the general rule of thumb should be “If it’s witty and insightful, Travis said it.” … and we’ll leave it at that.

Word of the day: Thixotropic

Eric’s talk at SciPy ’07 involved an example graph showing various properties of a thixotropic fluid. Thixotropy is a time-dependent decrease in the thickness of a fluid under a shearing force. The time dependence distinguishes a thixotropic fluid from a shear-thinning fluid; the latter recovers its original viscosity as soon as the shearing force is removed, as illustrated in this graph (different from Eric’s graph).

The most notable common thixotropic fluid is tomato ketchup. Thixotropy is why you can still pour the ketchup after you stop shaking the bottle. If ketchup were merely shear-thinning, you would have to keep shaking the bottle while pouring, which would be even messier. More likely, shear-thinning ketchup wouldn’t come in glass bottles. Most ketchup comes in squeezable plastic bottles these days, but if you encounter a glass ketchup bottle in a restaurant, there are several techniques for getting it to pour.

The word “thixotropy” derives from the Greek thixis, a touch, and tropos, to turn or change. While the -tropy suffix is common in scientific terminology, thixo- is much less so. The root appears more often as thigmo-. The only other thixo- form is thixophobia, irrational fear of touching or being touched.

ETS 2.5 to be released today

After a last round of checks with people external to Enthought (i.e non-employees who contribute to our open source,) it is clear we’re ready to release ETS 2.5 today. Yay! Starting this afternoon, I will tag each of the ETS 2.5 projects and also copy them to the ‘autobuilding’ directory. It is the autobuilding directory that will ensure they get built on every platform Enthought supports — well, after we get the autobuilding infrastructure setup on those platforms. 🙂 So far, we’re only close to auto-building on Windows XP and RHEL3, but the others (MacOSX, Ubuntu, etc.) shouldn’t be too far behind! I’ll also ensure source tarballs and zipballs are generated and uploaded to the source repo.

ETS 2.5 plans

We’re down to the last planned changes before publishing a release of ETS 2.5! The plan is to add and enable a set of dependency links that should enable someone to install any ETS project without downloading every other dependent ETS project egg. i.e. to install enthought.traits, I only need to manually acquire an enthought.traits egg. Basically, we’re putting into each egg’s metadata a few links to the web repo’s source and unstable source pages so that easy_install can download and install any dependencies you don’t already have installed or downloaded. Yesterday, I checked in an initial stab at this and had time to make one test by trying to install the ‘ets’ metaegg itself — without having any other ETS eggs available. Things got most of the way through until it got to Kiva which got a build error because it doesn’t build correctly using the standard setuptools build command (it requires a build_src and a few others to be explicitly specified — we’ll have to fix this somehow!) Other than that hiccup, we may be ready to go!