Damien Lespiau
fabde384a3
stats: Add support for the interquartile range (IQR)
...
IQR is a good measure of dispersion.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:04:08 +01:00
Damien Lespiau
1b8997b3f8
stats: Add support for quartiles (and thus median)
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More stuff, quite useful characteristics of a dataset.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:04:08 +01:00
Damien Lespiau
3839bacde8
stats: Add a bulk version of _push()
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In case we want to push a bunch of values in one go.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:04:08 +01:00
Damien Lespiau
0e4c175e04
stats: Add igt_stats_get_range()
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Somewhat useful, for instance to size an histogram.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:04:07 +01:00
Damien Lespiau
4a89a841a1
stats: Add functions to retrieve min/max values of the dataset
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Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:04:07 +01:00
Damien Lespiau
17ed69fbb8
stats: Add a note about the standard deviation derived from unbiased variance
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Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:04:07 +01:00
Damien Lespiau
da123adeae
stats: Add a getter for the population property
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Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:04:07 +01:00
Damien Lespiau
3a5cf84317
stats: Add a way to specify if the data set is a population or a sample
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This changes how we compute the variance. We want an unbiased variance
when reasoning about a sample.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:04:07 +01:00
Damien Lespiau
a2f6fd3725
stats: Add gtkdoc section for igt_stats
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Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:04:07 +01:00
Damien Lespiau
203c3841fc
stats: Zero the whole structure at init() time
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Because the structure started small, I initialized every member
directly, but that means that the new fields added weren't properly
initialized (sigh!). Zero the whole thing first then.
Also, the punishment for introducing a bug should be to write the
corresponding unit test. It's not a perfect one, but I'll take it.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:04:07 +01:00
Damien Lespiau
515cec1210
stats: Add a way to retrieve the standard deviation
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Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:03:27 +01:00
Damien Lespiau
05c10f940f
stats: Use an algorithm popularised by Knuth to compute mean and variance
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Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:03:27 +01:00
Damien Lespiau
e55a11d3eb
stats: Be more precise and talk about mean, not average
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There are several types of averages eg. mean, median and mode.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-27 16:03:27 +01:00
Damien Lespiau
06f5f7065f
lib: Add a tiny utility function to compute averages
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The master plan would be to get a bit more stats in it, at least the
standard deviation and confidence interval. Just need the average for
now.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
2015-06-25 17:22:03 +01:00
