# Statsample

Homepage :: https://github.com/sciruby/statsample

# Installation

You should have a recent version of GSL and R (with the `irr`

and `Rserve`

libraries) installed. In Ubuntu:

```
$ sudo apt-get install libgsl0-dev r-base r-base-dev
$ sudo Rscript -e "install.packages(c('Rserve', 'irr'))"
```

With these libraries in place, just install from rubygems:

`$ [sudo] gem install statsample`

On *nix, you should install statsample-optimization to retrieve gems gsl, statistics2 and a C extension to speed some methods.

`$ [sudo] gem install statsample-optimization`

If you need to work on Structural Equation Modeling, you could see +statsample-sem+. You need R with +sem+ or +OpenMx+ [http://openmx.psyc.virginia.edu/] libraries installed

`$ [sudo] gem install statsample-sem`

# Testing

See CONTRIBUTING for information on testing and contributing to statsample.

# Documentation

You can see the latest documentation in rubydoc.info.

# Usage

## Notebooks

You can see some iruby notebooks here:

### Statistics

- Correlation Matrix with daru and statsample
- Dominance Analysis with statsample
- Reliability ICC
- Levene Test
- Multiple Regression
- Parallel Analysis on PCA
- Polychoric Analysis
- Reliability Scale and Multiscale Analysis
- Velicer MAP Test

### Visualizations

### Working with DataFrame and Vector

- Creating Vectors and DataFrames with daru
- Detailed Usage of Daru::Vector
- Detailed Usage of Daru::DataFrame
- Visualizing Data with Daru::DataFrame

## Examples

See the /examples directory for some use cases. The notebooks listed above have mostly the same examples, and they look better so you might want to see that first.

# Description

A suite for basic and advanced statistics on Ruby. Tested on CRuby 2.0.0, 2.1.1, 2.2 and 2.3.0 See `.travis.yml`

for more information.

Include:

- Descriptive statistics: frequencies, median, mean, standard error, skew, kurtosis (and many others).
- Correlations: Pearson's r, Spearman's rank correlation (rho), point biserial, tau a, tau b and gamma. Tetrachoric and Polychoric correlation provides by +statsample-bivariate-extension+ gem.
- Intra-class correlation
- Anova: generic and vector-based One-way ANOVA and Two-way ANOVA, with contrasts for One-way ANOVA.
- Tests: F, T, Levene, U-Mannwhitney.
- Regression: Simple, Multiple (OLS)
- Factorial Analysis: Extraction (PCA and Principal Axis), Rotation (Varimax, Equimax, Quartimax) and Parallel Analysis and Velicer's MAP test, for estimation of number of factors.
- Reliability analysis for simple scale and a DSL to easily analyze multiple scales using factor analysis and correlations, if you want it.
- Basic time series support
- Dominance Analysis, with multivariate dependent and bootstrap (Azen & Budescu)
- Sample calculation related formulas
- Structural Equation Modeling (SEM), using R libraries +sem+ and +OpenMx+
- Creates reports on text, html and rtf, using ReportBuilder gem
- Graphics: Histogram, Boxplot and Scatterplot

## Principles

- Software Design:
- One module/class for each type of analysis
- Options can be set as hash on initialize() or as setters methods
- Clean API for interactive sessions
- summary() returns all necessary informacion for interactive sessions
- All statistical data available though methods on objects
- All (important) methods should be tested. Better with random data.

- Statistical Design
- Results are tested against text results, SPSS and R outputs.
- Go beyond Null Hiphotesis Testing, using confidence intervals and effect sizes when possible
- (When possible) All references for methods are documented, providing sensible information on documentation

# Features

- Classes for manipulation and storage of data:
- Uses daru for storing data and basic statistics.
- Statsample::Multiset: multiple datasets with same fields and type of vectors

- Anova module provides generic Statsample::Anova::OneWay and vector based Statsample::Anova::OneWayWithVectors. Also you can create contrast using Statsample::Anova::Contrast
- Module Statsample::Bivariate provides covariance and pearson, spearman, point biserial, tau a, tau b, gamma, tetrachoric (see Bivariate::Tetrachoric) and polychoric (see Bivariate::Polychoric) correlations. Include methods to create correlation and covariance matrices
- Multiple types of regression.
- Simple Regression : Statsample::Regression::Simple
- Multiple Regression: Statsample::Regression::Multiple

- Factorial Analysis algorithms on Statsample::Factor module.
- Classes for Extraction of factors:
- Statsample::Factor::PCA
- Statsample::Factor::PrincipalAxis

- Classes for Rotation of factors:
- Statsample::Factor::Varimax
- Statsample::Factor::Equimax
- Statsample::Factor::Quartimax

- Classes for calculation of factors to retain
- Statsample::Factor::ParallelAnalysis performs Horn's 'parallel analysis' to a principal components analysis to adjust for sample bias in the retention of components.
- Statsample::Factor::MAP performs Velicer's Minimum Average Partial (MAP) test, which retain components as long as the variance in the correlation matrix represents systematic variance.

- Classes for Extraction of factors:
- Dominance Analysis. Based on Budescu and Azen papers, dominance analysis is a method to analyze the relative importance of one predictor relative to another on multiple regression
- Statsample::DominanceAnalysis class can report dominance analysis for a sample, using uni or multivariate dependent variables
- Statsample::DominanceAnalysis::Bootstrap can execute bootstrap analysis to determine dominance stability, as recomended by Azen & Budescu (2003) link[http://psycnet.apa.org/journals/met/8/2/129/].

- Module Statsample::Codification, to help to codify open questions
- Converters to export data:
- Statsample::Mx : Write Mx Files
- Statsample::GGobi : Write Ggobi files

- Module Statsample::Crosstab provides function to create crosstab for categorical data
- Module Statsample::Reliability provides functions to analyze scales with psychometric methods.
- Class Statsample::Reliability::ScaleAnalysis provides statistics like mean, standard deviation for a scale, Cronbach's alpha and standarized Cronbach's alpha, and for each item: mean, correlation with total scale, mean if deleted, Cronbach's alpha is deleted.
- Class Statsample::Reliability::MultiScaleAnalysis provides a DSL to easily analyze reliability of multiple scales and retrieve correlation matrix and factor analysis of them.
- Class Statsample::Reliability::ICC provides intra-class correlation, using Shrout & Fleiss(1979) and McGraw & Wong (1996) formulations.

- Module Statsample::SRS (Simple Random Sampling) provides a lot of functions to estimate standard error for several type of samples
- Module Statsample::Test provides several methods and classes to perform inferencial statistics
- Statsample::Test::BartlettSphericity
- Statsample::Test::ChiSquare
- Statsample::Test::F
- Statsample::Test::KolmogorovSmirnov (only D value)
- Statsample::Test::Levene
- Statsample::Test::UMannWhitney
- Statsample::Test::T
- Statsample::Test::WilcoxonSignedRank

- Module Graph provides several classes to create beautiful graphs using rubyvis
- Statsample::Graph::Boxplot
- Statsample::Graph::Histogram
- Statsample::Graph::Scatterplot

- Gem bio-statsample-timeseries provides module Statsample::TimeSeries with support for time series, including ARIMA estimation using Kalman-Filter.
- Gem statsample-sem provides a DSL to R libraries +sem+ and +OpenMx+
- Gem statsample-glm provides you with GML method, to work with Logistic, Poisson and Gaussian regression ,using ML or IRWLS.
- Close integration with gem reportbuilder, to easily create reports on text, html and rtf formats.

# Resources

- Source code on github :: http://github.com/sciruby/statsample
- Bug report and feature request :: http://github.com/sciruby/statsample/issues
- E-mailing list :: https://groups.google.com/forum/#!forum/sciruby-dev

# License

BSD-3 (See LICENSE.txt)

Could change between version, without previous warning. If you want a specific license, just choose the version that you need.