Using anndataR
Robrecht Cannoodt
Luke Zappia
Martin Morgan
Louise Deconinck
Source:vignettes/anndataR.Rmd
anndataR.RmdIntroduction
{anndataR} allows users to work with
.h5ad files, access various slots in the datasets and
convert these files to SingleCellExperiment objects or
Seurat objects, and vice versa. This enables users to move
data easily between the different programming languages and analysis
ecosystems needed to perform single-cell data analysis. This package
differs from zellkonverter
because it reads and writes these .h5ad files natively in
R, and allows conversion to and from Seurat objects as
well.
Check out ?anndataR for a full list of the functions
provided by this package.
Installation
Install using:
if (!require("pak", quietly = TRUE)) {
install.packages("pak")
}
pak::pak("scverse/anndataR")Usage
Here’s a quick example of how to use {anndataR}.
First, we fetch an example .h5ad file included in the
package:
library(anndataR)
h5ad_path <- system.file("extdata", "example.h5ad", package = "anndataR")Read an h5ad file in memory:
adata <- read_h5ad(h5ad_path)Read an h5ad file on disk:
adata <- read_h5ad(h5ad_path, as = "HDF5AnnData")View structure:
adata
#> AnnData object with n_obs × n_vars = 50 × 100
#> obs: 'Float', 'FloatNA', 'Int', 'IntNA', 'Bool', 'BoolNA', 'n_genes_by_counts', 'log1p_n_genes_by_counts', 'total_counts', 'log1p_total_counts', 'leiden'
#> var: 'String', 'n_cells_by_counts', 'mean_counts', 'log1p_mean_counts', 'pct_dropout_by_counts', 'total_counts', 'log1p_total_counts', 'highly_variable', 'means', 'dispersions', 'dispersions_norm'
#> uns: 'Bool', 'BoolNA', 'Category', 'DataFrameEmpty', 'Int', 'IntNA', 'IntScalar', 'Sparse1D', 'String', 'String2D', 'StringScalar', 'hvg', 'leiden', 'log1p', 'neighbors', 'pca', 'rank_genes_groups', 'umap'
#> obsm: 'X_pca', 'X_umap'
#> varm: 'PCs'
#> layers: 'counts', 'csc_counts', 'dense_X', 'dense_counts'
#> obsp: 'connectivities', 'distances'Access AnnData slots:
dim(adata$X)
#> [1] 50 100
adata$obs[1:5, 1:6]
#> Float FloatNA Int IntNA Bool BoolNA
#> Cell000 42.42 NaN 0 NA FALSE FALSE
#> Cell001 42.42 42.42 1 42 TRUE NA
#> Cell002 42.42 42.42 2 42 TRUE TRUE
#> Cell003 42.42 42.42 3 42 TRUE TRUE
#> Cell004 42.42 42.42 4 42 TRUE TRUE
adata$var[1:5, 1:6]
#> String n_cells_by_counts mean_counts log1p_mean_counts
#> Gene000 String0 44 1.94 1.078410
#> Gene001 String1 42 2.04 1.111858
#> Gene002 String2 43 2.12 1.137833
#> Gene003 String3 41 1.72 1.000632
#> Gene004 String4 42 2.06 1.118415
#> pct_dropout_by_counts total_counts
#> Gene000 12 97
#> Gene001 16 102
#> Gene002 14 106
#> Gene003 18 86
#> Gene004 16 103Interoperability
Convert the AnnData object to a SingleCellExperiment object:
sce <- adata$as_SingleCellExperiment()
sce
#> class: SingleCellExperiment
#> dim: 100 50
#> metadata(18): Bool BoolNA ... rank_genes_groups umap
#> assays(5): counts csc_counts dense_X dense_counts X
#> rownames(100): Gene000 Gene001 ... Gene098 Gene099
#> rowData names(11): String n_cells_by_counts ... dispersions
#> dispersions_norm
#> colnames(50): Cell000 Cell001 ... Cell048 Cell049
#> colData names(11): Float FloatNA ... log1p_total_counts leiden
#> reducedDimNames(2): X_pca X_umap
#> mainExpName: NULL
#> altExpNames(0):Convert the AnnData object to a Seurat object:
obj <- adata$as_Seurat()
obj
#> An object of class Seurat
#> 100 features across 50 samples within 1 assay
#> Active assay: RNA (100 features, 0 variable features)
#> 5 layers present: counts, csc_counts, dense_X, dense_counts, X
#> 2 dimensional reductions calculated: X_pca, X_umapConvert a SingleCellExperiment object to an AnnData object:
adata <- as_AnnData(sce)
adata
#> AnnData object with n_obs × n_vars = 50 × 100
#> obs: 'Float', 'FloatNA', 'Int', 'IntNA', 'Bool', 'BoolNA', 'n_genes_by_counts', 'log1p_n_genes_by_counts', 'total_counts', 'log1p_total_counts', 'leiden'
#> var: 'String', 'n_cells_by_counts', 'mean_counts', 'log1p_mean_counts', 'pct_dropout_by_counts', 'total_counts', 'log1p_total_counts', 'highly_variable', 'means', 'dispersions', 'dispersions_norm'
#> uns: 'Bool', 'BoolNA', 'Category', 'DataFrameEmpty', 'Int', 'IntNA', 'IntScalar', 'Sparse1D', 'String', 'String2D', 'StringScalar', 'hvg', 'leiden', 'log1p', 'neighbors', 'pca', 'rank_genes_groups', 'umap'
#> obsm: 'X_pca', 'X_umap'
#> varm: 'X_pca'
#> layers: 'counts', 'csc_counts', 'dense_X', 'dense_counts', 'X'
#> obsp: 'connectivities', 'distances'Convert a Seurat object to an AnnData object:
adata <- as_AnnData(obj)
adata
#> AnnData object with n_obs × n_vars = 50 × 100
#> obs: 'orig.ident', 'nCount_RNA', 'nFeature_RNA', 'Float', 'FloatNA', 'Int', 'IntNA', 'Bool', 'BoolNA', 'n_genes_by_counts', 'log1p_n_genes_by_counts', 'total_counts', 'log1p_total_counts', 'leiden'
#> var: 'String', 'n_cells_by_counts', 'mean_counts', 'log1p_mean_counts', 'pct_dropout_by_counts', 'total_counts', 'log1p_total_counts', 'highly_variable', 'means', 'dispersions', 'dispersions_norm'
#> uns: 'Bool', 'BoolNA', 'Category', 'DataFrameEmpty', 'Int', 'IntNA', 'IntScalar', 'Sparse1D', 'String', 'String2D', 'StringScalar', 'hvg', 'leiden', 'log1p', 'neighbors', 'pca', 'rank_genes_groups', 'umap'
#> obsm: 'X_pca', 'X_umap'
#> varm: 'X_pca'
#> layers: 'counts', 'csc_counts', 'dense_X', 'dense_counts', 'X'
#> obsp: 'connectivities', 'distances'Manually create an object
adata <- AnnData(
X = matrix(rnorm(100), nrow = 10),
obs = data.frame(
cell_type = factor(rep(c("A", "B"), each = 5))
),
var = data.frame(
gene_name = paste0("gene_", 1:10)
)
)
adata
#> AnnData object with n_obs × n_vars = 10 × 10
#> obs: 'cell_type'
#> var: 'gene_name'Write to disk:
Write an AnnData object to disk:
tmpfile <- tempfile(fileext = ".h5ad")
write_h5ad(adata, tmpfile)Write an SCE object to disk:
tmpfile <- tempfile(fileext = ".h5ad")
write_h5ad(sce, tmpfile)Write a Seurat object to disk:
tmpfile <- tempfile(fileext = ".h5ad")
write_h5ad(obj, tmpfile)Session info
sessionInfo()
#> R version 4.5.1 (2025-06-13)
#> Platform: x86_64-pc-linux-gnu
#> Running under: Ubuntu 24.04.2 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=C.UTF-8 LC_NUMERIC=C LC_TIME=C.UTF-8
#> [4] LC_COLLATE=C.UTF-8 LC_MONETARY=C.UTF-8 LC_MESSAGES=C.UTF-8
#> [7] LC_PAPER=C.UTF-8 LC_NAME=C LC_ADDRESS=C
#> [10] LC_TELEPHONE=C LC_MEASUREMENT=C.UTF-8 LC_IDENTIFICATION=C
#>
#> time zone: UTC
#> tzcode source: system (glibc)
#>
#> attached base packages:
#> [1] stats4 stats graphics grDevices utils datasets methods
#> [8] base
#>
#> other attached packages:
#> [1] anndataR_0.1.0.9004 SingleCellExperiment_1.30.1
#> [3] SummarizedExperiment_1.38.1 Biobase_2.68.0
#> [5] GenomicRanges_1.60.0 GenomeInfoDb_1.44.0
#> [7] IRanges_2.42.0 S4Vectors_0.46.0
#> [9] BiocGenerics_0.54.0 generics_0.1.4
#> [11] MatrixGenerics_1.20.0 matrixStats_1.5.0
#> [13] SeuratObject_5.1.0 sp_2.2-0
#> [15] BiocStyle_2.36.0
#>
#> loaded via a namespace (and not attached):
#> [1] RColorBrewer_1.1-3 jsonlite_2.0.0 magrittr_2.0.3
#> [4] spatstat.utils_3.1-4 farver_2.1.2 rmarkdown_2.29
#> [7] fs_1.6.6 ragg_1.4.0 vctrs_0.6.5
#> [10] ROCR_1.0-11 spatstat.explore_3.4-3 htmltools_0.5.8.1
#> [13] S4Arrays_1.8.1 SparseArray_1.8.0 sass_0.4.10
#> [16] sctransform_0.4.2 parallelly_1.45.0 KernSmooth_2.23-26
#> [19] bslib_0.9.0 htmlwidgets_1.6.4 desc_1.4.3
#> [22] ica_1.0-3 plyr_1.8.9 plotly_4.11.0
#> [25] zoo_1.8-14 cachem_1.1.0 igraph_2.1.4
#> [28] mime_0.13 lifecycle_1.0.4 pkgconfig_2.0.3
#> [31] Matrix_1.7-3 R6_2.6.1 fastmap_1.2.0
#> [34] GenomeInfoDbData_1.2.14 fitdistrplus_1.2-4 future_1.58.0
#> [37] shiny_1.11.1 digest_0.6.37 patchwork_1.3.1
#> [40] tensor_1.5.1 Seurat_5.3.0 RSpectra_0.16-2
#> [43] irlba_2.3.5.1 textshaping_1.0.1 progressr_0.15.1
#> [46] spatstat.sparse_3.1-0 polyclip_1.10-7 httr_1.4.7
#> [49] abind_1.4-8 compiler_4.5.1 bit64_4.6.0-1
#> [52] fastDummies_1.7.5 MASS_7.3-65 DelayedArray_0.34.1
#> [55] tools_4.5.1 lmtest_0.9-40 httpuv_1.6.16
#> [58] future.apply_1.20.0 goftest_1.2-3 glue_1.8.0
#> [61] nlme_3.1-168 promises_1.3.3 grid_4.5.1
#> [64] Rtsne_0.17 cluster_2.1.8.1 reshape2_1.4.4
#> [67] hdf5r_1.3.12 spatstat.data_3.1-6 gtable_0.3.6
#> [70] tidyr_1.3.1 data.table_1.17.6 XVector_0.48.0
#> [73] spatstat.geom_3.4-1 RcppAnnoy_0.0.22 ggrepel_0.9.6
#> [76] RANN_2.6.2 pillar_1.11.0 stringr_1.5.1
#> [79] spam_2.11-1 RcppHNSW_0.6.0 later_1.4.2
#> [82] splines_4.5.1 dplyr_1.1.4 lattice_0.22-7
#> [85] deldir_2.0-4 survival_3.8-3 bit_4.6.0
#> [88] tidyselect_1.2.1 miniUI_0.1.2 pbapply_1.7-2
#> [91] knitr_1.50 gridExtra_2.3 bookdown_0.43
#> [94] scattermore_1.2 xfun_0.52 stringi_1.8.7
#> [97] UCSC.utils_1.4.0 lazyeval_0.2.2 yaml_2.3.10
#> [100] evaluate_1.0.4 codetools_0.2-20 tibble_3.3.0
#> [103] BiocManager_1.30.26 cli_3.6.5 uwot_0.2.3
#> [106] xtable_1.8-4 reticulate_1.42.0 systemfonts_1.2.3
#> [109] jquerylib_0.1.4 Rcpp_1.1.0 spatstat.random_3.4-1
#> [112] globals_0.18.0 png_0.1-8 spatstat.univar_3.1-3
#> [115] parallel_4.5.1 pkgdown_2.1.3 ggplot2_3.5.2
#> [118] dotCall64_1.2 listenv_0.9.1 viridisLite_0.4.2
#> [121] scales_1.4.0 ggridges_0.5.6 purrr_1.0.4
#> [124] crayon_1.5.3 rlang_1.1.6 cowplot_1.2.0