scrna4/6 Jupyter Notebook lamindata

Analyze a collection in memory

Here, we’ll analyze the growing collection by loading it into memory. This is only possible if it’s not too large. If your data is large, you’ll likely want to iterate over the collection to train a model, the topic of the next page (scrna5/6).

import lamindb as ln
import bionty as bt

ln.track("mfWKm8OtAzp80000")
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 connected lamindb: testuser1/test-scrna
 created Transform('mfWKm8Ot'), started new Run('Pz9zmEkC') at 2024-12-20 15:05:25 UTC
 notebook imports: bionty==0.53.2 lamindb==0.77.3 scanpy==1.10.4
ln.Collection.df()
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uid name description hash reference reference_type visibility transform_id meta_artifact_id version is_latest run_id created_at created_by_id
id
2 vU9vGhm9ozKWE66f0001 My versioned scRNA-seq collection None luH-jPb6eJLsXvc1TWGpUg None None 1 2 None 2 True 2 2024-12-20 15:05:15.781635+00:00 1
1 vU9vGhm9ozKWE66f0000 My versioned scRNA-seq collection None DuyXxlMxwF92YehyBLbhKg None None 1 1 None None False 1 2024-12-20 15:04:59.403847+00:00 1
collection = ln.Collection.get(name="My versioned scRNA-seq collection", version="2")
collection.artifacts.df()
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uid key description suffix type size hash n_objects n_observations _hash_type _accessor visibility _key_is_virtual storage_id transform_id version is_latest run_id created_at created_by_id
id
1 NAxy8G7q3xarNdqt0000 None Human immune cells from Conde22 .h5ad dataset 57612943 t_YJQpYrAyAGhs7Ir68zKj None 1648 sha1-fl AnnData 1 True 1 1 None True 1 2024-12-20 15:04:55.120402+00:00 1
3 Y0PbHhR9YXSu8sGt0001 None 10x reference adata, trusted cell type annotation .h5ad dataset 857336 GK721a-L-fGDI8kXefKMtA None 70 md5 AnnData 1 True 1 2 None True 2 2024-12-20 15:05:15.598075+00:00 1

If the collection isn’t too large, we can now load it into memory.

Under-the-hood, the AnnData objects are concatenated during loading.

The amount of time this takes depends on a variety of factors.

If it occurs often, one might consider storing a concatenated version of the collection, rather than the individual pieces.

adata = collection.load()

The default is an outer join during concatenation as in pandas:

adata
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AnnData object with n_obs × n_vars = 1718 × 36508
    obs: 'donor', 'tissue', 'cell_type', 'assay', 'cell_type_untrusted', 'n_genes', 'percent_mito', 'louvain', 'cell_type_untrusted_original', 'artifact_uid'
    obsm: 'X_umap', 'X_pca'

The AnnData has the reference to the individual artifacts in the .obs annotations:

adata.obs.artifact_uid.cat.categories
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Index(['NAxy8G7q3xarNdqt0000', 'Y0PbHhR9YXSu8sGt0001'], dtype='object')

We can easily obtain ensemble IDs for gene symbols using the look up object:

genes = bt.Gene.lookup(field="symbol")
genes.itm2b.ensembl_gene_id
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'ENSG00000136156'

Let us create a plot:

import scanpy as sc

sc.pp.pca(adata, n_comps=2)
sc.pl.pca(
    adata,
    color=genes.itm2b.ensembl_gene_id,
    title=(
        f"{genes.itm2b.symbol} / {genes.itm2b.ensembl_gene_id} /"
        f" {genes.itm2b.description}"
    ),
    save="_itm2b",
)
WARNING: saving figure to file figures/pca_itm2b.pdf
_images/71311d5974128efadc82eec7e7e5d8fb7aac60b8bca2c906e933f92032526a0f.png

We could save a plot as a pdf and then see it in the flow diagram:

artifact = ln.Artifact("./figures/pca_itm2b.pdf", description="My result on ITM2B")
artifact.save()
artifact.view_lineage()
_images/23735a84f8a457bccc5611a5ee3fe329bf7d35000660ab8ac009c3d0b3bedddb.svg

But given the image is part of the notebook, we can also rely on the report that we create when saving the notebook:

ln.finish()