erlangstat

A simple collection of statistical algorithms, functions to work with tables and a simple csv reader and writer. Input is a list of numbers.

There are no external dependencies, just pure Erlang.

stat.erl

Basic statistics:

• minmax/1 - basic statistics put into a record of type #stats
• print/1 - pretty print a #stats record
• avg/1 - average
• variance/1
• variance_welford/1 - variance using the welford algorithm
• median/1
• median_s/1 - median of a sample
• stddev/1 - standard deviation
• stddev_sample/1 - standard deviation of a sample
• sample_error/1 - standard error
• kurtosis and kurtosis_sample (biased)
• skewness and skewness_sample (unbiased)
• covar/2 - covariance
• covar_sample/2 - covariance of a sample
• correlation/2
• mode and multimode
• simple regression

hist.erl

• create/1 a histogram
• normalize/1 a histogram
• cumhist/1 cumhist/2 create a cumulative histogram
• ecdf/1

csv.erl

Read/write a csv file into a list of lists (a "table")

• read/1, read/2, - read a csv file
• write_list/2, write_list/3 - write to a file

table.erl

Functions for easier handling of lists of lists as created by the csv reader.

exports type table().

• get_col/2, get_col_if/3 - extract a column from a table
• print/1
• append_row/2 - appends a row
• get_row/1 - return the nth row
• subtable/2 - extract rows into a new table

examples

Examples on how to use the library