Contents

1 Getting Started

1.1 Installation

if (!require("BiocManager", quietly = TRUE))
    install.packages("BiocManager")

BiocManager::install("easylift")

1.2 Documentation

To view documentation:

browseVignettes("easylift")

1.3 Import

library("easylift")
#> Loading required package: GenomicRanges
#> Loading required package: stats4
#> Loading required package: BiocGenerics
#> Loading required package: generics
#> 
#> Attaching package: 'generics'
#> The following objects are masked from 'package:base':
#> 
#>     as.difftime, as.factor, as.ordered, intersect, is.element, setdiff,
#>     setequal, union
#> 
#> Attaching package: 'BiocGenerics'
#> The following objects are masked from 'package:stats':
#> 
#>     IQR, mad, sd, var, xtabs
#> The following objects are masked from 'package:base':
#> 
#>     Filter, Find, Map, Position, Reduce, anyDuplicated, aperm, append,
#>     as.data.frame, basename, cbind, colnames, dirname, do.call,
#>     duplicated, eval, evalq, get, grep, grepl, is.unsorted, lapply,
#>     mapply, match, mget, order, paste, pmax, pmax.int, pmin, pmin.int,
#>     rank, rbind, rownames, sapply, saveRDS, table, tapply, unique,
#>     unsplit, which.max, which.min
#> Loading required package: S4Vectors
#> 
#> Attaching package: 'S4Vectors'
#> The following object is masked from 'package:utils':
#> 
#>     findMatches
#> The following objects are masked from 'package:base':
#> 
#>     I, expand.grid, unname
#> Loading required package: IRanges
#> Loading required package: Seqinfo
#> Loading required package: BiocFileCache
#> Loading required package: dbplyr

1.4 Arguments

Create a GRanges object, assign a genome to it, and specify chain file

gr <- GRanges(
  seqname = Rle(
    c("chr1", "chr2"), 
    c(100000, 100000)
  ),
  ranges = IRanges(
    start = 1, end = 200000
  )
)
# Here, "hg19" is the source genome
genome(gr) <- "hg19"

# Here, we use the `system.file()` function because the chain file is in the
# package (however if you need to point to any other file on your machine,
# just do 'chain <- "path/to/your/hg19ToHg38.over.chain.gz"'):
chain <- system.file("extdata", "hg19ToHg38.over.chain.gz", package = "easylift")

gr
#> GRanges object with 200000 ranges and 0 metadata columns:
#>            seqnames    ranges strand
#>               <Rle> <IRanges>  <Rle>
#>        [1]     chr1  1-200000      *
#>        [2]     chr1  1-200000      *
#>        [3]     chr1  1-200000      *
#>        [4]     chr1  1-200000      *
#>        [5]     chr1  1-200000      *
#>        ...      ...       ...    ...
#>   [199996]     chr2  1-200000      *
#>   [199997]     chr2  1-200000      *
#>   [199998]     chr2  1-200000      *
#>   [199999]     chr2  1-200000      *
#>   [200000]     chr2  1-200000      *
#>   -------
#>   seqinfo: 2 sequences from hg19 genome; no seqlengths

1.5 Run

Call easylift with GRanges object, target genome and the chain file.

# Here, "hg38" is the target genome
easylift(gr, "hg38", chain)
#> GRanges object with 300000 ranges and 0 metadata columns:
#>            seqnames        ranges strand
#>               <Rle>     <IRanges>  <Rle>
#>        [1]     chr1  10001-177376      *
#>        [2]    chr19 242824-242864      *
#>        [3]     chr1  10001-177376      *
#>        [4]    chr19 242824-242864      *
#>        [5]     chr1  10001-177376      *
#>        ...      ...           ...    ...
#>   [299996]     chr2  10001-200000      *
#>   [299997]     chr2  10001-200000      *
#>   [299998]     chr2  10001-200000      *
#>   [299999]     chr2  10001-200000      *
#>   [300000]     chr2  10001-200000      *
#>   -------
#>   seqinfo: 25 sequences (1 circular) from hg38 genome

1.6 Run with BiocFileCache

To use BiocFileCache for the chain file, add it to the cache:

chain_file <- "/path/to/your/hg19ToHg38.over.chain.gz"
bfc <- BiocFileCache()

# Add chain file to cache if already not available
if (nrow(bfcquery(bfc, basename(chain_file))) == 0)
    bfcadd(bfc, chain_file)

Then, use it in easylift:

easylift(gr, "hg38") 
# or
gr |> easylift("hg38")

2 Citation

To cite package easylift in publications use:

Al Nahid A, Pagès H, Love M (2023). easylift: An R package to perform genomic liftover. R package version 1.0.0, https://github.com/nahid18/easylift.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {easylift: An R package to perform genomic liftover},
    author = {Abdullah Al Nahid, Hervé Pagès, Michael Love},
    year = {2023},
    note = {R package version 1.0.0},
    url = {https://github.com/nahid18/easylift},
  }

Please note that the easylift was only made possible thanks to many other R and bioinformatics software authors, which are cited either in the vignettes and/or the paper(s) describing this package.

3 Code of Conduct

Please note that the easylift project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.

4 Session information

sessionInfo()
#> R version 4.6.0 Patched (2026-05-01 r89994)
#> Platform: aarch64-apple-darwin23
#> Running under: macOS Tahoe 26.3.1
#> 
#> Matrix products: default
#> BLAS:   /Library/Frameworks/R.framework/Versions/4.6/Resources/lib/libRblas.0.dylib 
#> LAPACK: /Library/Frameworks/R.framework/Versions/4.6/Resources/lib/libRlapack.dylib;  LAPACK version 3.12.1
#> 
#> locale:
#> [1] C/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
#> 
#> time zone: America/New_York
#> tzcode source: internal
#> 
#> attached base packages:
#> [1] stats4    stats     graphics  grDevices utils     datasets  methods  
#> [8] base     
#> 
#> other attached packages:
#>  [1] easylift_1.11.0      BiocFileCache_3.3.0  dbplyr_2.5.2        
#>  [4] GenomicRanges_1.65.0 Seqinfo_1.3.0        IRanges_2.47.1      
#>  [7] S4Vectors_0.51.2     BiocGenerics_0.59.2  generics_0.1.4      
#> [10] BiocStyle_2.41.0    
#> 
#> loaded via a namespace (and not attached):
#>  [1] SummarizedExperiment_1.43.0 rjson_0.2.23               
#>  [3] xfun_0.57                   bslib_0.11.0               
#>  [5] httr2_1.2.2                 lattice_0.22-9             
#>  [7] Biobase_2.73.1              vctrs_0.7.3                
#>  [9] tools_4.6.0                 bitops_1.0-9               
#> [11] parallel_4.6.0              curl_7.1.0                 
#> [13] tibble_3.3.1                RSQLite_3.52.0             
#> [15] blob_1.3.0                  pkgconfig_2.0.3            
#> [17] BiocBaseUtils_1.15.1        R.oo_1.27.1                
#> [19] Matrix_1.7-5                cigarillo_1.3.0            
#> [21] lifecycle_1.0.5             compiler_4.6.0             
#> [23] Rsamtools_2.29.0            Biostrings_2.81.1          
#> [25] codetools_0.2-20            GenomeInfoDb_1.49.0        
#> [27] htmltools_0.5.9             sass_0.4.10                
#> [29] RCurl_1.98-1.18             yaml_2.3.12                
#> [31] pillar_1.11.1               crayon_1.5.3               
#> [33] jquerylib_0.1.4             R.utils_2.13.0             
#> [35] BiocParallel_1.47.0         DelayedArray_0.39.2        
#> [37] cachem_1.1.0                abind_1.4-8                
#> [39] tidyselect_1.2.1            digest_0.6.39              
#> [41] dplyr_1.2.1                 restfulr_0.0.16            
#> [43] bookdown_0.46               grid_4.6.0                 
#> [45] fastmap_1.2.0               SparseArray_1.13.2         
#> [47] cli_3.6.6                   magrittr_2.0.5             
#> [49] S4Arrays_1.13.0             XML_3.99-0.23              
#> [51] filelock_1.0.3              UCSC.utils_1.9.0           
#> [53] rappdirs_0.3.4              bit64_4.8.0                
#> [55] rmarkdown_2.31              XVector_0.53.0             
#> [57] httr_1.4.8                  matrixStats_1.5.0          
#> [59] bit_4.6.0                   otel_0.2.0                 
#> [61] R.methodsS3_1.8.2           memoise_2.0.1              
#> [63] evaluate_1.0.5              knitr_1.51                 
#> [65] BiocIO_1.23.3               rtracklayer_1.73.0         
#> [67] rlang_1.2.0                 glue_1.8.1                 
#> [69] DBI_1.3.0                   BiocManager_1.30.27        
#> [71] jsonlite_2.0.0              R6_2.6.1                   
#> [73] MatrixGenerics_1.25.0       GenomicAlignments_1.49.0