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Dear kst team:
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<div>I am working on an application where the data set is generated by x-ray sensors called TES microcalorimeters. The raw data are uniformly sampled time series, like in a CMB experiment, but with one key difference: most of our interest is in the random Poisson-distributed
"events" that correspond to an x-ray pulse arriving.</div>
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<div>I want to convince our team to shift our real-time plotting functions to kst. It will be better in a hundred ways, plus it would remove a serious code maintenance burden if we no longer had to roll our own plots.</div>
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<div>One big obstacle is that I can't figure out how to use kst for the data acquisition activity we currently use the most: plotting the most recent fixed-length pulse record from a given calorimeter. (Think: oscilloscope with triggering logic.) We store our
data in a non-standard format, so my plan was to start generating an auxiliary, temporary fixed-size dirfile field holding only the latest pulse record. At each trigger, this file gets overwritten. I've tried this concept. The result is that I can plot the
dirfile once, but GetData is smart enough <i>not</i> to re-read the dirfile when its contents change. (It does update if--but only if--I click the Reload All Data Sources button.)</div>
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<div>My question #1 for you all: Is there any way to convince kst2 (or GetData) that it needs to update a certain data source whose size has not grown? Maybe a clever use of cur-files?</div>
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<div>I can see a couple of workarounds, but they have their own problems. I could just copy all the pulse records to a dirfile and let it grow in the normal way, but this would be a complete duplication of our already large dataset.</div>
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<div>Or I could write a kst datasource plugin for our proprietary data files. (The website says to mail this list for help getting started on a plugin. Question #2: Can you help? Is it not so hard? I have plenty of C++ experience.) Our data file format is not
dissimilar to a one-field dirfile, but with timestamps interspersed and with a horrible ASCII header tacked on the head.</div>
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<div>Or I could just switch our system to writing dirfiles. This might be the best solution, but you can probably imagine there's some institutional inertia resisting this change.</div>
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<div>Thanks, gang.</div>
<div>Joe Fowler</div>
<div>NIST Boulder Labs</div>
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<div>System details: I am using Mac OS 10.8 with the latest kst2 binary from sourceforge (2.0.7, though I also tried 2.0.6), and the data are being generated in Python through GetData 0.8.5. In our lab environment, we will be running on an Ubuntu Linux system
instead.</div>
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