Re^2: Excel or Perl for simple statistics?

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Re^3: Excel or Perl for simple statistics? by pryrt (Abbot) on Jan 20, 2018 at 17:36 UTC
I believe davies was wrong about it also being called the standard error: according to wp, Standard_error, the standard error is the standard deviation divided by the root of the number of samples. The population standard deviation (Excel: `=STDEVP()` or `=STDEV.P()`) assumes you that have data for the entire population; the sample standard deviation (Excel: `=STDEV()` or `=STDEV.S()`) assumes that your `n` data points are just a sample of the population, so it uses a different denominator (`n-1`) inside the radical, to account for the uncertainty because it's just a sample, not the whole population. Given your set of data, the 0.401791 is the population standard deviation, and the 0.410689 is the sample standard deviation. Population standard deviation: σ = sqrt( Σ{ (x_i - x_avg)² } / { n } ) Sample standard deviation: s = sqrt( Σ{ (x_i - x_avg)² } / { n - 1 } ) According to Statistics::Basic, you can set `$Statistics::Basic::UNBIAS` true to get the sample, or (implied) set it false to get the population. Statistics::Lite directly says that their `stddev()` function is the unbiased (sample) n-1, which matches the Excel `=STDEV()` function, and they have the `stddevp()` for the population n, matching the Excel `=STDEVP()`.	[reply] [d/l] [select]
Re^3: Excel or Perl for simple statistics? by Anonymous Monk on Jan 20, 2018 at 16:38 UTC
Ok, so problem seems to be fixed if I use `Statistics::Lite` module instead... Do you think it could be associated to the fact that with `Statistics::Lite` I pass the numbers as array instead of array reference that I was using in `Statistics::Basic` My list was: `0.964 0 0 0.94 0.895 0.915 0.775 0.868 0 0.796 0.866 0.819 0 0 0 0 0.794 0.806 0.781 0.807 0.783` [download]	[reply] [d/l] [select]
Re^4: Excel or Perl for simple statistics? by poj (Abbot) on Jan 20, 2018 at 17:06 UTC
.. as array instead of array reference .. I get the same either way and no difference with Excel `#!perl use strict; use Statistics::Basic 'stddev'; my @data = (0.964, 0, 0, 0.94, 0.895, 0.915, 0.775, 0.868, 0, 0.796, 0.866, 0.819, 0, 0, 0, 0, 0.794, 0.806, 0.781, 0.807, 0.783); print stddev(\@data)+0; print "\n"; print stddev(@data)+0; # 0.400791162022762 # excel # STDEVP # Calculates standard deviation based # on the entire population given as arguments. # 0.400791162` [download] poj	[reply] [d/l]