Label projection
Automated cell type annotation from rich, labeled reference data
Repository:
openproblems-bio/task_label_projection
Description
A major challenge for integrating single cell datasets is creating
matching cell type annotations for each cell. One of the most common
strategies for annotating cell types is referred to as
“cluster-then-annotate”
whereby cells are aggregated into clusters based on feature similarity
and then manually characterized based on differential gene expression or
previously identified marker genes. Recently, methods have emerged to
build on this strategy and annotate cells using known marker
genes. However,
these strategies pose a difficulty for integrating atlas-scale datasets
as the particular annotations may not match.
To ensure that the cell type labels in newly generated datasets match
existing reference datasets, some methods align cells to a previously
annotated reference
dataset
and then project labels from the reference to the new dataset.
Here, we compare methods for annotation based on a reference dataset.
The datasets consist of two or more samples of single cell profiles that
have been manually annotated with matching labels. These datasets are
then split into training and test batches, and the task of each method
is to train a cell type classifer on the training set and project those
labels onto the test set.
Authors & contributors
name |
roles |
Nikolay Markov |
author, maintainer |
Scott Gigante |
author |
Robrecht Cannoodt |
author |
API
flowchart LR
file_common_dataset("Common Dataset")
comp_process_dataset[/"Data processor"/]
file_solution("Solution")
file_test("Test data")
file_train("Training data")
comp_control_method[/"Control method"/]
comp_metric[/"Metric"/]
comp_method[/"Method"/]
file_prediction("Prediction")
file_score("Score")
file_common_dataset---comp_process_dataset
comp_process_dataset-->file_solution
comp_process_dataset-->file_test
comp_process_dataset-->file_train
file_solution---comp_control_method
file_solution---comp_metric
file_test---comp_control_method
file_test---comp_method
file_train---comp_control_method
file_train---comp_method
comp_control_method-->file_prediction
comp_metric-->file_score
comp_method-->file_prediction
file_prediction---comp_metric
File format: Common Dataset
A subset of the common dataset.
Example file: resources_test/common/pancreas/dataset.h5ad
Format:
AnnData object
obs: 'cell_type', 'batch'
var: 'hvg', 'hvg_score'
obsm: 'X_pca'
layers: 'counts', 'normalized'
uns: 'dataset_id', 'dataset_name', 'dataset_url', 'dataset_reference', 'dataset_summary', 'dataset_description', 'dataset_organism', 'normalization_id'
Data structure:
| Slot | Type | Description |
|:---|:---|:---|
| `obs["cell_type"]` | `string` | Cell type information. |
| `obs["batch"]` | `string` | Batch information. |
| `var["hvg"]` | `boolean` | Whether or not the feature is considered to be a ‘highly variable gene’. |
| `var["hvg_score"]` | `double` | A ranking of the features by hvg. |
| `obsm["X_pca"]` | `double` | The resulting PCA embedding. |
| `layers["counts"]` | `integer` | Raw counts. |
| `layers["normalized"]` | `double` | Normalized expression values. |
| `uns["dataset_id"]` | `string` | A unique identifier for the dataset. |
| `uns["dataset_name"]` | `string` | Nicely formatted name. |
| `uns["dataset_url"]` | `string` | (*Optional*) Link to the original source of the dataset. |
| `uns["dataset_reference"]` | `string` | (*Optional*) Bibtex reference of the paper in which the dataset was published. |
| `uns["dataset_summary"]` | `string` | Short description of the dataset. |
| `uns["dataset_description"]` | `string` | Long description of the dataset. |
| `uns["dataset_organism"]` | `string` | (*Optional*) The organism of the sample in the dataset. |
| `uns["normalization_id"]` | `string` | Which normalization was used. |
Component type: Data processor
A label projection dataset processor.
Arguments:
| Name | Type | Description |
|:--------------------|:-------|:-------------------------------------------|
| `--input` | `file` | A subset of the common dataset. |
| `--output_train` | `file` | (*Output*) The training data. |
| `--output_test` | `file` | (*Output*) The test data (without labels). |
| `--output_solution` | `file` | (*Output*) The solution for the test data. |
File format: Solution
The solution for the test data
Example file:
resources_test/task_label_projection/pancreas/solution.h5ad
Format:
AnnData object
obs: 'label', 'batch'
var: 'hvg', 'hvg_score'
obsm: 'X_pca'
layers: 'counts', 'normalized'
uns: 'dataset_id', 'dataset_name', 'dataset_url', 'dataset_reference', 'dataset_summary', 'dataset_description', 'dataset_organism', 'normalization_id'
Data structure:
| Slot | Type | Description |
|:---|:---|:---|
| `obs["label"]` | `string` | Ground truth cell type labels. |
| `obs["batch"]` | `string` | Batch information. |
| `var["hvg"]` | `boolean` | Whether or not the feature is considered to be a ‘highly variable gene’. |
| `var["hvg_score"]` | `double` | A ranking of the features by hvg. |
| `obsm["X_pca"]` | `double` | The resulting PCA embedding. |
| `layers["counts"]` | `integer` | Raw counts. |
| `layers["normalized"]` | `double` | Normalized counts. |
| `uns["dataset_id"]` | `string` | A unique identifier for the dataset. |
| `uns["dataset_name"]` | `string` | Nicely formatted name. |
| `uns["dataset_url"]` | `string` | (*Optional*) Link to the original source of the dataset. |
| `uns["dataset_reference"]` | `string` | (*Optional*) Bibtex reference of the paper in which the dataset was published. |
| `uns["dataset_summary"]` | `string` | Short description of the dataset. |
| `uns["dataset_description"]` | `string` | Long description of the dataset. |
| `uns["dataset_organism"]` | `string` | (*Optional*) The organism of the sample in the dataset. |
| `uns["normalization_id"]` | `string` | Which normalization was used. |
File format: Test data
The test data (without labels)
Example file: resources_test/task_label_projection/pancreas/test.h5ad
Format:
AnnData object
obs: 'batch'
var: 'hvg', 'hvg_score'
obsm: 'X_pca'
layers: 'counts', 'normalized'
uns: 'dataset_id', 'normalization_id'
Data structure:
| Slot | Type | Description |
|:---|:---|:---|
| `obs["batch"]` | `string` | Batch information. |
| `var["hvg"]` | `boolean` | Whether or not the feature is considered to be a ‘highly variable gene’. |
| `var["hvg_score"]` | `double` | A ranking of the features by hvg. |
| `obsm["X_pca"]` | `double` | The resulting PCA embedding. |
| `layers["counts"]` | `integer` | Raw counts. |
| `layers["normalized"]` | `double` | Normalized counts. |
| `uns["dataset_id"]` | `string` | A unique identifier for the dataset. |
| `uns["normalization_id"]` | `string` | Which normalization was used. |
File format: Training data
The training data
Example file: resources_test/task_label_projection/pancreas/train.h5ad
Format:
AnnData object
obs: 'label', 'batch'
var: 'hvg', 'hvg_score'
obsm: 'X_pca'
layers: 'counts', 'normalized'
uns: 'dataset_id', 'normalization_id'
Data structure:
| Slot | Type | Description |
|:---|:---|:---|
| `obs["label"]` | `string` | Ground truth cell type labels. |
| `obs["batch"]` | `string` | Batch information. |
| `var["hvg"]` | `boolean` | Whether or not the feature is considered to be a ‘highly variable gene’. |
| `var["hvg_score"]` | `double` | A ranking of the features by hvg. |
| `obsm["X_pca"]` | `double` | The resulting PCA embedding. |
| `layers["counts"]` | `integer` | Raw counts. |
| `layers["normalized"]` | `double` | Normalized counts. |
| `uns["dataset_id"]` | `string` | A unique identifier for the dataset. |
| `uns["normalization_id"]` | `string` | Which normalization was used. |
Component type: Control method
Quality control methods for verifying the pipeline.
Arguments:
| Name | Type | Description |
|:-------------------|:-------|:--------------------------------|
| `--input_train` | `file` | The training data. |
| `--input_test` | `file` | The test data (without labels). |
| `--input_solution` | `file` | The solution for the test data. |
| `--output` | `file` | (*Output*) The prediction file. |
Component type: Metric
A label projection metric.
Arguments:
| Name | Type | Description |
|:---------------------|:-------|:--------------------------------|
| `--input_solution` | `file` | The solution for the test data. |
| `--input_prediction` | `file` | The prediction file. |
| `--output` | `file` | (*Output*) Metric score file. |
Component type: Method
A label projection method.
Arguments:
| Name | Type | Description |
|:----------------|:-------|:--------------------------------|
| `--input_train` | `file` | The training data. |
| `--input_test` | `file` | The test data (without labels). |
| `--output` | `file` | (*Output*) The prediction file. |
File format: Prediction
The prediction file
Example file:
resources_test/task_label_projection/pancreas/prediction.h5ad
Format:
AnnData object
obs: 'label_pred'
uns: 'dataset_id', 'normalization_id', 'method_id'
Data structure:
| Slot | Type | Description |
|:--------------------------|:---------|:-------------------------------------|
| `obs["label_pred"]` | `string` | Predicted labels for the test cells. |
| `uns["dataset_id"]` | `string` | A unique identifier for the dataset. |
| `uns["normalization_id"]` | `string` | Which normalization was used. |
| `uns["method_id"]` | `string` | A unique identifier for the method. |
File format: Score
Metric score file
Example file: resources_test/task_label_projection/pancreas/score.h5ad
Format:
AnnData object
uns: 'dataset_id', 'normalization_id', 'method_id', 'metric_ids', 'metric_values'
Data structure:
| Slot | Type | Description |
|:---|:---|:---|
| `uns["dataset_id"]` | `string` | A unique identifier for the dataset. |
| `uns["normalization_id"]` | `string` | Which normalization was used. |
| `uns["method_id"]` | `string` | A unique identifier for the method. |
| `uns["metric_ids"]` | `string` | One or more unique metric identifiers. |
| `uns["metric_values"]` | `double` | The metric values obtained for the given prediction. Must be of same length as ‘metric_ids’. |