Author: oldchap

Delete orphaned jobs in Condor

I had occasion recently to delete a lot of jobs in Condor that were orphaned. This means that they’d stalled, condor_rm had been called on them, and they’d kept the machines “claimed”. condor_rm -forcex had removed them from the global queue but the machines remained claimed! In this situation, we really need to call condor_vacate on […]

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Hanns-G HX191D monitor repair

Maybe this will be useful to someone! Many years back (2006 I think) I bought two Hanns G HX191D monitors – 19″ TFTs – and have been very happy with them since. Not a dead pixel in 10 years! Sadly, one of them started cutting out a few months ago, the power cycling on-off, so […]

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Lots of piping!

Today I needed to lower the run priority of a load of jobs running on one of my linux boxes, and this needed the above command. I was quite please with it, four commands, each piping output to the next: ps-ef lists the running processes on the system egrep… filters them to python3 jobs owned […]

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Reusing PCA for plotting in R

I’m currently working on a project where I’m using principal component analysis to scale lots of variables into 2 dimensions for visualisation. Something like this:   This figure shows a number of features (numbers) relating to a few thousand bin packing problem instances. Each point is one instance, coloured by the data set it originally came from. […]

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Car Audio

A couple of times over the past year I’ve replaced a factory-fitted CD player with an aftermarket one. In both cases (my car, a 2004 VW Touran, and my parents’ 2006 Peugeot 206), the ability to play CDs was failing. Several years ago, I also replaced the tape player in my 1996 VW Passat – this was […]

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Copy file attributes only

I’ve recently bought a 3TB hard drive to replace the now-full 750GB one in my desktop. I copied all the data across a couple of days ago, but of course I forgot to copy attributes, so now all my files have modified dates of 2015 instead of when they truly originated. This isn’t all that important […]

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