1 Overview

This vignette shows how to build a SpatialExperiment (SPE) from: - Nanostring CosMx (RNA/protein) outputs - 10x Genomics Xenium outputs

For each technology, we demonstrate: - Route A: SpaceTrooper’s high-level reader (readCosmxSPE, readCosmxProteinSPE, readXeniumSPE) - Route B: read with SpatialExperimentIO, then standardize with updateCosmxSPE / updateXeniumSPE

2 CosMx (Nanostring)

We begin with CosMx. The package ships with a small CosMx example for demonstration.

cospath <- system.file(file.path("extdata", "CosMx_DBKero_Tiny"), package="SpaceTrooper")
cospath
#> [1] "/tmp/RtmpaWTLmh/Rinst2adb0d52563f17/SpaceTrooper/extdata/CosMx_DBKero_Tiny"

2.1 Route A — Direct loading with SpaceTrooper

Use readCosmxSPE() to construct an SPE from CosMx outputs; it also normalizes names/metadata and records polygons/FOV info if present.

spe_cos <- readCosmxSPE(
    dirName=cospath,
    sampleName="DBKero_Tiny",
    coordNames=c("CenterX_global_px", "CenterY_global_px"),
    countMatFPattern="exprMat_file.csv",
    metadataFPattern="metadata_file.csv",
    polygonsFPattern="polygons.csv",
    fovPosFPattern="fov_positions_file.csv",
    fovdims=c(xdim=4256, ydim=4256)
)
spe_cos
#> class: SpatialExperiment 
#> dim: 1010 905 
#> metadata(4): fov_positions fov_dim polygons technology
#> assays(1): counts
#> rownames(1010): RAMP2 CD83 ... NegPrb09 NegPrb10
#> rowData names(0):
#> colnames(905): f16_c1 f16_c10 ... f16_c98 f16_c99
#> colData names(20): fov cellID ... sample_id cell_id
#> reducedDimNames(0):
#> mainExpName: NULL
#> altExpNames(0):
#> spatialCoords names(2) : CenterX_global_px CenterY_global_px
#> imgData names(1): sample_id

Inspect essentials:

assayNames(spe_cos)
#> [1] "counts"
dim(spe_cos)
#> [1] 1010  905
head(colnames(spatialCoords(spe_cos)))
#> [1] "CenterX_global_px" "CenterY_global_px"
metadata(spe_cos)$technology
#> [1] "Nanostring_CosMx"
metadata(spe_cos)$polygons
#> [1] "/tmp/RtmpaWTLmh/Rinst2adb0d52563f17/SpaceTrooper/extdata/CosMx_DBKero_Tiny/DBKero-polygons.csv"

2.1.1 CosMx protein

If working with CosMx Protein, use the convenience wrapper:

protfolder <- system.file("extdata", "S01_prot", package = "SpaceTrooper")
spe_cos_prot <- readCosmxProteinSPE(
    dirName=protfolder,
    sampleName="cosmx_prots",
    coordNames=c("CenterX_global_px", "CenterY_global_px"),
    countMatFPattern="exprMat_file.csv",
    metadataFPattern="metadata_file.csv",
    polygonsFPattern="polygons.csv",
    fovPosFPattern="fov_positions_file.csv",
    fovdims=c(xdim=4256, ydim=4256)
)
metadata(spe_cos_prot)$technology

2.2 Route B — Via SpatialExperimentIO, then standardize

If you prefer to read with SpatialExperimentIO first, upgrade the object with updateCosmxSPE() to harmonize names/metadata and attach polygons.

spe_cos_raw <- SpatialExperimentIO::readCosmxSXE(
    dirName=cospath,
    returnType="SPE",
    countMatPattern="exprMat_file.csv",
    metaDataPattern="metadata_file.csv",
    coordNames=c("CenterX_global_px", "CenterY_global_px"),
    addFovPos=TRUE,
    fovPosPattern="fov_positions_file.csv",
    altExps=NULL,
    addParquetPaths=FALSE
)

spe_cos_std <- updateCosmxSPE(
    spe=spe_cos_raw,
    dirName=cospath,
    sampleName="DBKero_Tiny",
    polygonsFPattern="polygons.csv",
    fovdims=c(xdim=4256, ydim=4256)
)

identical(spe_cos_std, spe_cos)
#> [1] TRUE

3 Xenium (10x Genomics)

A small Xenium example is also included for demonstration.

xepath <- system.file("extdata", "Xenium_small", package = "SpaceTrooper")
xepath
#> [1] "/tmp/RtmpaWTLmh/Rinst2adb0d52563f17/SpaceTrooper/extdata/Xenium_small"

3.1 Route A — Direct loading with SpaceTrooper

readXeniumSPE() builds the SPE from a Xenium Output Bundle (root or outs/) and standardizes metadata.

Key options: - type: "HDF5" or "sparse" (feature matrix) - boundariesType: "parquet" or "csv" (cell boundaries) - computeMissingMetrics: compute QC metrics (area/aspect ratio) if needed - keepPolygons: append polygons to colData - addFOVs: derive FOV IDs from transcript parquet

spe_xen_a <- readXeniumSPE(
    dirName=xepath,
    type="HDF5",
    coordNames=c("x_centroid", "y_centroid"),
    boundariesType="parquet",
    computeMissingMetrics=TRUE,
    keepPolygons=TRUE,
    countsFilePattern="cell_feature_matrix",
    metadataFPattern="cells.csv.gz",
    polygonsFPattern="cell_boundaries",
    polygonsCol="polygons",
    txPattern="transcripts",
    addFOVs=FALSE
)
#> Computing missing metrics, this could take some time...
spe_xen_a
#> class: SpatialExperiment 
#> dim: 4 6 
#> metadata(2): polygons technology
#> assays(1): counts
#> rownames(4): ABCC11 ACTA2 ACTG2 ADAM9
#> rowData names(3): ID Symbol Type
#> colnames(6): 1 2 ... 5 6
#> colData names(11): X cell_id ... Area_um polygons
#> reducedDimNames(0):
#> mainExpName: NULL
#> altExpNames(0):
#> spatialCoords names(2) : x_centroid y_centroid
#> imgData names(1): sample_id

Quick checks:

assayNames(spe_xen_a)
#> [1] "counts"
dim(spe_xen_a)
#> [1] 4 6
colnames(spatialCoords(spe_xen_a))
#> [1] "x_centroid" "y_centroid"
metadata(spe_xen_a)$polygons
#> [1] "/tmp/RtmpaWTLmh/Rinst2adb0d52563f17/SpaceTrooper/extdata/Xenium_small/cell_boundaries.parquet"
metadata(spe_xen_a)$technology
#> [1] "10X_Xenium"

3.2 Route B — Via SpatialExperimentIO, then standardize

Read with SpatialExperimentIO and then pass through updateXeniumSPE() for SpaceTrooper-standardized metadata and optional metrics/FOV extraction.

spe_xen_b <- SpatialExperimentIO::readXeniumSXE(
    dirName=xepath,
    countMatPattern="cell_feature_matrix.h5",
    metaDataPattern="cells.csv.gz",
    coordNames=c("x_centroid", "y_centroid"),
    returnType="SPE",
    addExperimentXenium=FALSE,
    altExps=NULL,
    addParquetPaths=FALSE
) 

spe_xen_b <- updateXeniumSPE(
    spe=spe_xen_b,
    dirName=xepath,
    boundariesType="parquet",
    computeMissingMetrics=TRUE,
    keepPolygons=TRUE,
    polygonsFPattern="cell_boundaries",
    polygonsCol="polygons",
    txPattern="transcripts",
    addFOVs=FALSE
) 
#> Computing missing metrics, this could take some time...

spe_xen_b
#> class: SpatialExperiment 
#> dim: 4 6 
#> metadata(2): polygons technology
#> assays(1): counts
#> rownames(4): ABCC11 ACTA2 ACTG2 ADAM9
#> rowData names(3): ID Symbol Type
#> colnames(6): 1 2 ... 5 6
#> colData names(11): X cell_id ... Area_um polygons
#> reducedDimNames(0):
#> mainExpName: NULL
#> altExpNames(0):
#> spatialCoords names(2) : x_centroid y_centroid
#> imgData names(1): sample_id

Validate:

identical(metadata(spe_xen_b)$technology, "10X_Xenium")
#> [1] TRUE
identical(spe_xen_a, spe_xen_b)
#> [1] TRUE

4 File layout notes

  • CosMx: per-cell metadata (e.g. metadata_file.csv), expression matrix (exprMat_file.csv), optional polygon CSV (polygons.csv), and FOV positions. updateCosmxSPE() also fixes common field names and records FOV dims in metadata.
  • Xenium: unzipped bundle contains an outs/ folder. Feature matrix may be cell_feature_matrix.h5 (HDF5) or sparse folder; cells metadata cells.csv.gz; boundaries as .parquet or .csv.gz; transcript parquet for FOV attribution. readXeniumSPE() auto-detects outs/ if you pass the bundle root.

5 Session info

sessionInfo()
#> R Under development (unstable) (2026-01-15 r89304)
#> Platform: x86_64-pc-linux-gnu
#> Running under: Ubuntu 24.04.3 LTS
#> 
#> Matrix products: default
#> BLAS:   /home/biocbuild/bbs-3.23-bioc/R/lib/libRblas.so 
#> LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.12.0  LAPACK version 3.12.0
#> 
#> locale:
#>  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
#>  [3] LC_TIME=en_GB              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: America/New_York
#> tzcode source: system (glibc)
#> 
#> attached base packages:
#> [1] stats4    stats     graphics  grDevices utils     datasets  methods  
#> [8] base     
#> 
#> other attached packages:
#>  [1] ggplot2_4.0.1               SpaceTrooper_1.1.4         
#>  [3] SpatialExperiment_1.21.0    SingleCellExperiment_1.33.0
#>  [5] SummarizedExperiment_1.41.0 Biobase_2.71.0             
#>  [7] GenomicRanges_1.63.1        Seqinfo_1.1.0              
#>  [9] IRanges_2.45.0              S4Vectors_0.49.0           
#> [11] BiocGenerics_0.57.0         generics_0.1.4             
#> [13] MatrixGenerics_1.23.0       matrixStats_1.5.0          
#> [15] BiocStyle_2.39.0           
#> 
#> loaded via a namespace (and not attached):
#>   [1] RColorBrewer_1.1-3        jsonlite_2.0.0           
#>   [3] shape_1.4.6.1             magrittr_2.0.4           
#>   [5] ggbeeswarm_0.7.3          magick_2.9.0             
#>   [7] farver_2.1.2              rmarkdown_2.30           
#>   [9] vctrs_0.7.1               DelayedMatrixStats_1.33.0
#>  [11] tinytex_0.58              rstatix_0.7.3            
#>  [13] htmltools_0.5.9           S4Arrays_1.11.1          
#>  [15] BiocNeighbors_2.5.2       broom_1.0.11             
#>  [17] Rhdf5lib_1.33.0           SparseArray_1.11.10      
#>  [19] Formula_1.2-5             rhdf5_2.55.12            
#>  [21] sass_0.4.10               KernSmooth_2.23-26       
#>  [23] bslib_0.10.0              cachem_1.1.0             
#>  [25] lifecycle_1.0.5           iterators_1.0.14         
#>  [27] pkgconfig_2.0.3           rsvd_1.0.5               
#>  [29] Matrix_1.7-4              R6_2.6.1                 
#>  [31] fastmap_1.2.0             digest_0.6.39            
#>  [33] scater_1.39.2             dqrng_0.4.1              
#>  [35] irlba_2.3.5.1             ggpubr_0.6.2             
#>  [37] beachmat_2.27.2           labeling_0.4.3           
#>  [39] SpatialExperimentIO_1.3.0 abind_1.4-8              
#>  [41] compiler_4.6.0            proxy_0.4-29             
#>  [43] bit64_4.6.0-1             withr_3.0.2              
#>  [45] S7_0.2.1                  backports_1.5.0          
#>  [47] BiocParallel_1.45.0       carData_3.0-5            
#>  [49] viridis_0.6.5             DBI_1.2.3                
#>  [51] HDF5Array_1.39.0          R.utils_2.13.0           
#>  [53] ggsignif_0.6.4            DelayedArray_0.37.0      
#>  [55] rjson_0.2.23              classInt_0.4-11          
#>  [57] tools_4.6.0               units_1.0-0              
#>  [59] vipor_0.4.7               otel_0.2.0               
#>  [61] beeswarm_0.4.0            R.oo_1.27.1              
#>  [63] glue_1.8.0                h5mread_1.3.1            
#>  [65] rhdf5filters_1.23.3       grid_4.6.0               
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#>  [73] BiocSingular_1.27.1       ScaledMatrix_1.19.0      
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#>  [77] ggrepel_0.9.6             foreach_1.5.2            
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#>  [81] robustbase_0.99-6         splines_4.6.0            
#>  [83] dplyr_1.1.4               lattice_0.22-7           
#>  [85] survival_3.8-6            bit_4.6.0                
#>  [87] tidyselect_1.2.1          locfit_1.5-9.12          
#>  [89] scuttle_1.21.0            sfheaders_0.4.5          
#>  [91] knitr_1.51                gridExtra_2.3            
#>  [93] bookdown_0.46             edgeR_4.9.2              
#>  [95] xfun_0.56                 statmod_1.5.1            
#>  [97] DropletUtils_1.31.0       DEoptimR_1.1-4           
#>  [99] yaml_2.3.12               evaluate_1.0.5           
#> [101] codetools_0.2-20          tibble_3.3.1             
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#> [105] arrow_23.0.0              jquerylib_0.1.4          
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