scrna4/6 Jupyter Notebook lamindata

Analyze a dataset in memory#

Here, we’ll analyze the growing dataset 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 dataset to train a model, the topic of the next page (scrna5/6).

import lamindb as ln
import lnschema_bionty as lb
import anndata as ad
💡 lamindb instance: testuser1/test-scrna
💡 notebook imports: anndata==0.9.2 lamindb==0.63.4 lnschema_bionty==0.35.3 scanpy==1.9.6
💡 saved: Transform(uid='mfWKm8OtAzp8z8', name='Analyze a dataset in memory', short_name='scrna4', version='0', type=notebook, updated_at=2023-12-08 11:40:15 UTC, created_by_id=1)
💡 saved: Run(uid='wihsFEM2dT2QJkytrxNp', run_at=2023-12-08 11:40:15 UTC, transform_id=4, created_by_id=1)
uid name description version hash reference reference_type transform_id run_id file_id storage_id initial_version_id visibility updated_at created_by_id
1 5TLFD3BeG0JgOu3DZOqf My versioned scRNA-seq dataset None 1 9sXda5E7BYiVoDOQkTC0KB None None 1 1 1.0 None NaN 1 2023-12-08 11:39:32.404399+00:00 1
2 CWQMw6Uyq6Ho5mlvHm4W My versioned scRNA-seq dataset None 2 BOAf0T5UbN_iOe3fQDyq None None 2 2 NaN None 1.0 1 2023-12-08 11:40:03.549010+00:00 1
dataset = ln.Dataset.filter(name="My versioned scRNA-seq dataset", version="2").one()
uid storage_id key suffix accessor description version size hash hash_type transform_id run_id initial_version_id visibility key_is_virtual updated_at created_by_id
1 5TLFD3BeG0JgOu3DZOqf 1 scrna/conde22.h5ad .h5ad AnnData Human immune cells from Conde22 None 57612943 9sXda5E7BYiVoDOQkTC0KB sha1-fl 1 1 None 1 True 2023-12-08 11:39:32.399667+00:00 1
2 4IlGq6zGzg8LjkkvZOV6 1 None .h5ad AnnData 10x reference adata None 853388 eKH1ljAEh7Kd81-o2H4A7w md5 2 2 None 1 True 2023-12-08 11:40:02.225003+00:00 1

If the dataset doesn’t consist of too many files, 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 dataset, rather than the individual pieces.

adata = dataset.load()

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

AnnData object with n_obs × n_vars = 1718 × 36503
    obs: 'donor', 'tissue', 'cell_type', 'assay', 'n_genes', 'percent_mito', 'louvain', 'file_uid'
    obsm: 'X_umap', 'X_pca'

The AnnData has the reference to the individual files in the .obs annotations:
Index(['5TLFD3BeG0JgOu3DZOqf', '4IlGq6zGzg8LjkkvZOV6'], dtype='object')

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

genes = lb.Gene.lookup(field="symbol")

Let us create a plot:

import scanpy as sc

sc.pp.pca(adata, n_comps=2)
2023-12-08 11:40:18,302:INFO - Failed to extract font properties from /usr/share/fonts/truetype/noto/NotoColorEmoji.ttf: In FT2Font: Can not load face (unknown file format; error code 0x2)
2023-12-08 11:40:18,363:INFO - generated new fontManager
        f"{genes.itm2b.symbol} / {genes.itm2b.ensembl_gene_id} /"
        f" {genes.itm2b.description}"
WARNING: saving figure to file figures/pca_itm2b.pdf

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

file = ln.File("./figures/pca_itm2b.pdf", description="My result on ITM2B")
Hide code cell output

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

lamin save <notebook_path>

To see the current notebook, visit: