Title: Statistics

1 Methods

In Ruby/GSL, all the GSL statistical functions are provided as methods for the GSL::Vector class, and singleton methods of the GSL::Stats module.

GSL::Stats.mean(v)

GSL::Vector#mean

Arithmetic mean

GSL::Stats.variance(v)

GSL::Vector#variance

Estimated variance

GSL::Stats.sd(v)

GSL::Vector#sd

Standard deviation

The following is a list of other methods defined both as singleton methods of the GSL::Stats module and methods of the GSL::Vector class. See the GSL reference for details.

• variance_m
• sd
• sd_m
• variace_with_fixed_mean
• sd_with_fixed_mean
• absdev
• absdev_m
• skew
• skew_m_sd
• kurtosis
• kurtosis_m_sd
• lag1_autocorrelation
• lag1_autocorrelation_m
• max
• min
• minmax
• max_index
• min_index
• minmax_index
• median_from_sorted_data
• uantile_from_sorted_data

These are singleton methods of the GSL::Stats module.

• covariance
• covariance_m
• wmean
• wmean_m
• wvariance
• wvariance_m
• wsd
• wsd_m
• wvariance_with_fixed_mean
• wsd_with_fixed_mean
• wabsdev
• wabsdev_m
• wskew
• wskew_m_sd
• wkurtosis
• wkurtosis_m_sd

2 Example

#!/usr/bin/env ruby
require 'gsl'
include GSL

ary =  [17.2, 18.1, 16.5, 18.3, 12.6]
data = Vector.new(ary)
mean     = data.mean()
variance = data.stats_variance()
largest  = data.stats_max()
smallest = data.stats_min()

printf("The dataset is %g, %g, %g, %g, %g\n",
       data[0], data[1], data[2], data[3], data[4]);

printf("The sample mean is %g\n", mean);
printf("The estimated variance is %g\n", variance);
printf("The largest value is %g\n", largest);
printf("The smallest value is %g\n", smallest);

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