# Preprocessing: `pp`

```{eval-rst}
.. module:: patpy.pp
```

```{eval-rst}
.. currentmodule:: patpy
```

```{eval-rst}
.. autosummary::
    :toctree: ../generated

    pp.prepare_data_for_phemd
    pp.convert_cell_types_to_phemd_format
    pp.calculate_compositional_metrics
    pp.calculate_cell_qc_metrics
    pp.calculate_n_cells_per_sample
    pp.filter_small_samples
    pp.filter_small_cell_groups
    pp.subsample
    pp.is_count_data
    pp.fill_nan_distances
```