liger

R package for integrating and analyzing multiple single-cell datasets

View the Project on GitHub MacoskoLab/liger

LIGER (Linked Inference of Genomic Experimental Relationships)

LIGER (liger) is a package for integrating and analyzing multiple single-cell datasets, developed and maintained by the Macosko lab. It relies on integrative non-negative matrix factorization to identify shared and dataset-specific factors.

LIGER can be used to compare and contrast experimental datasets in a variety of contexts, for instance:

Once multiple datasets are integrated, the package provides functionality for further data exploration, analysis, and visualization. Users can:

We have also designed LIGER to interface with existing single-cell analysis packages, including Seurat.

Read our preprint for a more complete description of the methods and to see examples of other analyses.

Usage

For usage examples and guided walkthroughs, check the vignettes directory of the repo.

Installation

liger is written in R and has a few other system requirements (Java) and recommended packages (umap in Python). To install the most recent development version, follow these instructions:

  1. Install R (>= 3.4)
  2. Install Rstudio (recommended)
  3. Make sure you have Java installed in your machine. Check by typing java -version into Terminal or CommandPrompt.
  4. Use the following R commands.
    install.packages('devtools')
    library(devtools)
    install_github('MacoskoLab/liger')
    

Installing RcppArmadillo on R>=3.4 requires Clang >= 4 and gfortran-6.1. Follow the instructions below if you have R version 3.4.0-3.4.4. These instructions (using clang4) may also be sufficient for R>=3.5 but for newer versions of R, it’s recommended to follow the instructions in this post.

  1. Install gfortran as suggested here
  2. Download clang4 from this page
  3. Uncompress the resulting zip file and type into Terminal (sudo if needed):
    mv /path/to/clang4/ /usr/local/ 
    
  4. Create .R/Makevars file containing following:
    # The following statements are required to use the clang4 binary
    CC=/usr/local/clang4/bin/clang
    CXX=/usr/local/clang4/bin/clang++
    CXX11=/usr/local/clang4/bin/clang++
    CXX14=/usr/local/clang4/bin/clang++
    CXX17=/usr/local/clang4/bin/clang++
    CXX1X=/usr/local/clang4/bin/clang++
    LDFLAGS=-L/usr/local/clang4/lib
    

    For example, use the following Terminal commands:

    cd ~
    mkdir .R
    cd .R 
    nano Makevars
    

    Paste in the required text above and save with Ctrl-X.

Using FIt-SNE is recommended for computational efficiency when using runTSNE on very large datasets. Installing and compiling the necessary software requires the use of git, FIt-SNE, and FFTW. For a basic overview of installation, visit this page.

Basic installation for most Unix machines can be achieved with the following commands after downloading the latest version of FFTW from here. In the fftw directory, run:

./configure
make
make install

(Additional instructions if necessary). Then in desired directory:

git clone https://github.com/KlugerLab/FIt-SNE.git
cd FIt-SNE
g++ -std=c++11 -O3  src/sptree.cpp src/tsne.cpp src/nbodyfft.cpp  -o bin/fast_tsne -pthread -lfftw3 -lm
pwd

Use the output of pwd as the fitsne.path parameter in runTSNE.