`cint` - a confidence interval calculator

cint is a simple script to calculate the confidence interval of a collection of numbers (using the Student's t-distribution).

The motivation behind it comes from the need to calculate confidence intervals of program runtime samples. This is a very common task when working to improve the performance of a program. With that in mind, cint aims to solve a very localized and niche problem but doing it as simple and user friendly as possible.

Installation

Just place cint somewhere covered by your $PATH.

Using

tl;dr

$ cint -n 1 2 3

> 2.0 ± 2.484 (confidence of 0.95)

$ cint --confidence 0.99
1, 2;  3

> 2.0 ± 2.484 (confidence of 0.95)

cint --help will list all the valid options.

Confidence level

By default, a confidence level of 0.95 (95%) is used. You can override that with the --confidence/-c option.

Input options

The numbers can be given through three different ways:

stdin (default);
A csv-like file, using the --file/-f option; or
By CLI, using the --numbers/-n option.

The first two options accept float numbers separated by \s, \n, , or ;, and ending with an EOF (for stdin, that's ctrl+D in most terminals).

The third option only accepts \s as separators and the numbers must not be surrounded by quotes.

Output options

The default output is in the format mean ± margin of error. But you can adjust the output format as you like, using the following tokens:

%M: sample mean
%N: sample size
%S: sample standard deviation
%E: margin of error
%L: lower limit of the confidence interval
%U: upper limit of the confidente interval
%C: the confidence level used as decimal
%c: the confidence level as a percentage
%s: sum
%i: min
%a: max
%[1-4]: use one of the predefined formats (see bellow)
%%: a single '%' character

To control how many decimal digits to display in the output, use the --digits option.

Predefined formats

The current predefined formats available are:

%1: '%M ± %E (confidence of %C)'
%2: '[%L, %U] (confidence of %C)'
%3: '%L, %U'
%4: 'With %c%% of confidence, the population mean is between %L and %U.'

matheustavares/cint

cint - a confidence interval calculator