# Packaging the igraph C library

# Overview

Rigraphlib builds the igraph static library for use in R/Bioconductor packages. This is primarily intended for R packages that wrap other C/C++ libraries that depend on the igraph C library and cannot easily be modified to use the usual igraph R package. By vendoring in the source code, we also reduce our susceptibility to out-of-release-schedule changes in results due to igraph updates. This also allows developers to access functionality that might yet not be available from the R bindings.

Currently, this package contains version 0.10.15 of the C igraph library.

# Quick start

Downstream package developers can use Rigraphlib by adding:

    Imports: Rigraphlib

to their package `DESCRIPTION`, and setting:

    RIGRAPH_FLAGS=$(shell "${R_HOME}/bin${R_ARCH_BIN}/Rscript" -e 'Rigraphlib::pkgconfig("PKG_CPPFLAGS")')
    PKG_CPPFLAGS=$(RIGRAPH_FLAGS)
    RIGRAPH_LIBS=$(shell "${R_HOME}/bin${R_ARCH_BIN}/Rscript" -e 'Rigraphlib::pkgconfig("PKG_LIBS")')
    PKG_LIBS=$(RIGRAPH_LIBS) $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS)

in their `src/Makevars`. We use R’s own BLAS and LAPACK libraries to avoid redundant recompilation of igraph’s vendored copies.

# Session information

    sessionInfo()

    ## R version 4.5.2 (2025-10-31)
    ## Platform: x86_64-pc-linux-gnu
    ## Running under: Ubuntu 24.04.3 LTS
    ##
    ## Matrix products: default
    ## BLAS:   /usr/lib/x86_64-linux-gnu/openblas-pthread/libblas.so.3
    ## LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/libopenblasp-r0.3.26.so;  LAPACK version 3.12.0
    ##
    ## locale:
    ##  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
    ##  [3] LC_TIME=en_US.UTF-8        LC_COLLATE=C
    ##  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
    ##  [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
    ##  [9] LC_ADDRESS=C               LC_TELEPHONE=C
    ## [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
    ##
    ## time zone: Etc/UTC
    ## tzcode source: system (glibc)
    ##
    ## attached base packages:
    ## [1] stats     graphics  grDevices utils     datasets  methods   base
    ##
    ## other attached packages:
    ## [1] knitr_1.51       BiocStyle_2.38.0
    ##
    ## loaded via a namespace (and not attached):
    ##  [1] digest_0.6.39       R6_2.6.1            fastmap_1.2.0
    ##  [4] xfun_0.56           maketools_1.3.2     cachem_1.1.0
    ##  [7] htmltools_0.5.9     rmarkdown_2.30      buildtools_1.0.0
    ## [10] lifecycle_1.0.5     cli_3.6.5           sass_0.4.10
    ## [13] jquerylib_0.1.4     compiler_4.5.2      sys_3.4.3
    ## [16] tools_4.5.2         evaluate_1.0.5      bslib_0.10.0
    ## [19] yaml_2.3.12         BiocManager_1.30.27 jsonlite_2.0.0
    ## [22] rlang_1.1.7