Pancreas PairScorer tutorial

This notebook demonstrates a complete replicate-aware two-condition pancreas
analysis. In `DEMO_MODE`, balanced pseudo-conditions and a controlled transition
tilt toward Beta are used only to validate the API. They are not biological data.
For a real study, set `DEMO_MODE=False`, provide genuine condition/replicate
columns, and use the unmodified velocity transition matrix.

Execution provenance. The displayed outputs were generated with scCS 0.8.0.dev33. Version 0.8.0.dev34 changes documentation and tutorial explanation only; the scientific calculations are unchanged.

1. Installation, versions, and analysis settings

[1]:
from __future__ import annotations
import warnings

from pathlib import Path
import importlib.metadata as importlib_metadata
import platform
import sys

import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import scanpy as sc
import scvelo as scv
from scipy.spatial.distance import jensenshannon

import scCS

SEED = 20260714
N_JOBS = 1
sc.settings.verbosity = 2
scv.settings.verbosity = 2
sc.set_figure_params(dpi=100, facecolor="white")

print("Python", sys.version.split()[0])
print("Platform", platform.platform())
print("scCS", scCS.__version__)
print("Scanpy", importlib_metadata.version("scanpy"))
print("scVelo", scv.__version__)

OUTPUT_DIR = Path("tutorial_outputs/pancreas_pair")
OUTPUT_DIR.mkdir(parents=True, exist_ok=True)

# Hide known warnings emitted by optional upstream dependencies. These do not
# change the scCS calculation and would otherwise distract from the tutorial.
warnings.filterwarnings(
    "ignore",
    message=r"This process .* is multi-threaded, use of fork\(\) may lead to deadlocks.*",
    category=DeprecationWarning,
)
warnings.filterwarnings(
    "ignore",
    category=DeprecationWarning,
    module=r"cellrank\..*",
)

Python 3.12.13
Platform Linux-6.6.114.1-microsoft-standard-WSL2-x86_64-with-glibc2.39
scCS 0.8.0.dev33
Scanpy 1.11.5
scVelo 0.3.4
[2]:
DEMO_MODE = True
CONDITION_KEY = "condition"
REPLICATE_KEY = "sample_id"
CONDITIONS = ("control", "treated")
REPLICATES_PER_CONDITION = 5
RUN_SCOPE_SENSITIVITY = False
RUN_MIXED_MODEL_SENSITIVITY = False

2. Load the dataset and velocity graph

This tutorial deliberately starts from the public dataset and recomputes the velocity model. No pre-existing scCS cache is assumed. Dynamical fitting can take several minutes, but showing the complete preparation makes every analysis step reproducible for a first-time user.

[3]:
def clear_velocity_outputs(adata, *, clear_dynamics=False):
    """Remove stale velocity fields before fitting a requested model."""
    for key in ("velocity", "velocity_u", "velocity_variance"):
        adata.layers.pop(key, None)
    for key in ("velocity_graph", "velocity_graph_neg", "velocity_params"):
        adata.uns.pop(key, None)
    for key in (
        "velocity_self_transition",
        "root_cells",
        "end_points",
        "velocity_pseudotime",
        "latent_time",
    ):
        if key in adata.obs:
            del adata.obs[key]
    if clear_dynamics:
        for key in list(adata.var.columns):
            if str(key).startswith("fit_"):
                del adata.var[key]
        for key in list(adata.layers):
            if str(key).startswith("fit_"):
                del adata.layers[key]
        adata.uns.pop("recover_dynamics", None)


def ensure_pca_neighbors_moments(
    adata,
    *,
    n_pcs=30,
    n_neighbors=30,
    preserve_existing_neighbors=False,
):
    """Create the unbiased PCA neighbor graph used by RNA velocity."""
    if "X_pca" not in adata.obsm:
        n_comps = min(n_pcs, adata.n_obs - 1, adata.n_vars - 1)
        sc.pp.pca(adata, n_comps=n_comps)
    if "neighbors" not in adata.uns or not preserve_existing_neighbors:
        sc.pp.neighbors(
            adata,
            n_neighbors=min(n_neighbors, adata.n_obs - 1),
            n_pcs=min(n_pcs, adata.obsm["X_pca"].shape[1]),
            use_rep="X_pca",
            random_state=SEED,
        )
    if not {"Ms", "Mu"}.issubset(adata.layers):
        scv.pp.moments(adata, n_neighbors=None, n_pcs=None)
    if "X_umap" not in adata.obsm:
        sc.tl.umap(adata, random_state=SEED)


def resolve_present_genes(adata, candidates):
    """Resolve gene symbols case-insensitively and report missing markers."""
    lookup = {str(gene).lower(): str(gene) for gene in adata.var_names}
    resolved, missing = [], []
    for candidate in candidates:
        match = lookup.get(str(candidate).lower())
        if match is None:
            missing.append(str(candidate))
        elif match not in resolved:
            resolved.append(match)
    return resolved, missing


def row_js(left, right):
    """Row-wise Jensen-Shannon divergence with base-2 logarithms."""
    return np.asarray(
        [jensenshannon(a, b, base=2.0) ** 2 for a, b in zip(left, right)],
        dtype=float,
    )


def ordering_thirds(values):
    """Return stable early/middle/late labels for a continuous coordinate."""
    series = pd.Series(np.asarray(values, dtype=float))
    ranked = series.rank(method="first")
    return (
        pd.qcut(
            ranked,
            q=3,
            labels=["early", "middle", "late"],
            duplicates="drop",
        )
        .astype(str)
        .to_numpy()
    )
[4]:
RECOVER_DYNAMICS_MAX_ITER = 20

# Load the public scVelo pancreas dataset.
adata = scv.datasets.pancreas()
adata.var_names_make_unique()

# Fit RNA velocity in the original expression/PCA manifold.
scv.pp.filter_and_normalize(adata, min_shared_counts=20)
ensure_pca_neighbors_moments(
    adata,
    n_pcs=30,
    n_neighbors=30,
    preserve_existing_neighbors=False,
)
clear_velocity_outputs(adata, clear_dynamics=True)

# Dynamical velocity is used because the pancreas dataset contains several
# kinetic regimes and non-monotonic terminal trajectories.
scv.tl.recover_dynamics(
    adata,
    max_iter=RECOVER_DYNAMICS_MAX_ITER,
    n_jobs=N_JOBS,
)
scv.tl.velocity(adata, mode="dynamical")
scv.tl.velocity_graph(adata, n_jobs=N_JOBS)
scv.tl.terminal_states(adata)
scv.tl.latent_time(
    adata,
    vkey="velocity",
    root_key="root_cells",
    end_key="end_points",
)
scv.tl.velocity_pseudotime(adata, vkey="velocity")

print(adata)
display(adata.obs["clusters"].astype(str).value_counts().to_frame("n_cells"))
Filtered out 20801 genes that are detected 20 counts (shared).
Normalized count data: X, spliced, unspliced.
computing neighbors
    finished (0:00:08)
computing moments based on connectivities
    finished (0:00:02)
recovering dynamics (using 1/24 cores)
/home/emil/miniforge3/envs/lab-py312/lib/python3.12/multiprocessing/popen_fork.py:66: DeprecationWarning: This process (pid=91733) is multi-threaded, use of fork() may lead to deadlocks in the child.
  self.pid = os.fork()
    finished (0:26:54)
computing velocities
    finished (0:00:09)
computing velocity graph (using 1/24 cores)
/home/emil/miniforge3/envs/lab-py312/lib/python3.12/multiprocessing/popen_fork.py:66: DeprecationWarning: This process (pid=91733) is multi-threaded, use of fork() may lead to deadlocks in the child.
  self.pid = os.fork()
    finished (0:00:16)
computing terminal states
    identified 2 regions of root cells and 1 region of end points .
    finished (0:00:00)
computing latent time using root_cells, end_points as prior
    finished (0:00:03)
AnnData object with n_obs × n_vars = 3696 × 7197
    obs: 'clusters_coarse', 'clusters', 'S_score', 'G2M_score', 'initial_size_unspliced', 'initial_size_spliced', 'initial_size', 'n_counts', 'velocity_self_transition', 'root_cells', 'end_points', 'velocity_pseudotime', 'latent_time'
    var: 'highly_variable_genes', 'gene_count_corr', 'fit_r2', 'fit_alpha', 'fit_beta', 'fit_gamma', 'fit_t_', 'fit_scaling', 'fit_std_u', 'fit_std_s', 'fit_likelihood', 'fit_u0', 'fit_s0', 'fit_pval_steady', 'fit_steady_u', 'fit_steady_s', 'fit_variance', 'fit_alignment_scaling', 'velocity_genes'
    uns: 'clusters_coarse_colors', 'clusters_colors', 'day_colors', 'neighbors', 'pca', 'recover_dynamics', 'velocity_params', 'velocity_graph', 'velocity_graph_neg'
    obsm: 'X_pca', 'X_umap'
    varm: 'loss'
    layers: 'spliced', 'unspliced', 'Ms', 'Mu', 'fit_t', 'fit_tau', 'fit_tau_', 'velocity', 'velocity_u'
    obsp: 'distances', 'connectivities'
n_cells
clusters
Ductal 916
Ngn3 high EP 642
Pre-endocrine 592
Beta 591
Alpha 481
Ngn3 low EP 262
Epsilon 142
Delta 70

3. Inspect the native velocity field

[5]:
native_color = "clusters"
scv.pl.velocity_embedding_stream(
    adata,
    basis="umap",
    color=native_color,
    legend_loc="right margin",
    title="Native RNA-velocity field",
)
computing velocity embedding
    finished (0:00:00)
../_images/tutorials_03_pancreas_pair_scorer_9_1.png

4. Define the supervised furcation and future-fate settings

[6]:
ROOT = ("Ngn3 high EP", "Pre-endocrine")
FATES = ["Alpha", "Beta", "Delta", "Epsilon"]
OBS_KEY = "clusters"
ORDERING_KEY = "latent_time"
TARGET_FATE = "Beta"
FUTURE_OPTIONS = {
    "effective_horizon": 64,
    "anchor_quantile": 0.90,
    "min_anchor_cells": 10,
    "progression_scale": "rank",
}

5. Real-study metadata or controlled demonstration design

A scientific analysis must use genuine biological replicates. The controlled demonstration balances state and ordering composition across pseudo-replicates, then tilts root-cell transition probabilities toward destinations with higher baseline target-fate probability. The transition support is unchanged and every row remains normalized.

[7]:
def assign_stratified_demo_design(
    adata,
    *,
    annotation_key,
    ordering_key,
    conditions,
    replicates_per_condition,
    condition_key="condition",
    replicate_key="sample_id",
    n_ordering_bins=5,
    random_state=0,
):
    """Create balanced technical pseudo-conditions within state/order strata.

    This helper is for tutorial validation only. It must not replace genuine
    biological condition and replicate metadata in a scientific analysis.
    """
    annotations = adata.obs[annotation_key].astype(str)
    ordering = pd.to_numeric(adata.obs[ordering_key], errors="coerce")
    if ordering.isna().any():
        raise ValueError(f"{ordering_key!r} contains missing or nonnumeric values.")
    strata = pd.Series(index=adata.obs_names, dtype=object)
    for annotation, indices in annotations.groupby(annotations).groups.items():
        indices = pd.Index(indices)
        values = ordering.loc[indices]
        n_bins = min(n_ordering_bins, len(indices), int(values.nunique()))
        if n_bins <= 1:
            bins = pd.Series("0", index=indices)
        else:
            bins = pd.qcut(
                values.rank(method="first"),
                q=n_bins,
                labels=False,
                duplicates="drop",
            ).astype(str)
        strata.loc[indices] = str(annotation) + "::" + bins

    conditions = tuple(map(str, conditions))
    combinations = [
        (condition, f"{condition}_R{replicate + 1}")
        for condition in conditions
        for replicate in range(int(replicates_per_condition))
    ]
    rng = np.random.default_rng(random_state)
    assigned_condition = pd.Series(index=adata.obs_names, dtype=object)
    assigned_replicate = pd.Series(index=adata.obs_names, dtype=object)
    for _, indices in strata.groupby(strata, sort=True).groups.items():
        indices = np.asarray(list(indices), dtype=object)
        rng.shuffle(indices)
        for position, index in enumerate(indices):
            condition, replicate = combinations[position % len(combinations)]
            assigned_condition.loc[index] = condition
            assigned_replicate.loc[index] = replicate

    adata.obs[condition_key] = pd.Categorical(
        assigned_condition,
        categories=list(conditions),
        ordered=True,
    )
    adata.obs[replicate_key] = pd.Categorical(assigned_replicate)
    return pd.DataFrame(
        {
            "stratum": strata.astype(str),
            condition_key: adata.obs[condition_key].astype(str),
            replicate_key: adata.obs[replicate_key].astype(str),
        },
        index=adata.obs_names,
    )


def target_destination_score(adata, result, *, annotation_key, target_fate):
    """Map baseline target-fate probability to every destination cell."""
    score = np.zeros(adata.n_obs, dtype=float)
    selected_indices = adata.obs_names.get_indexer(result.cell_ids)
    if np.any(selected_indices < 0):
        raise ValueError("Result cells could not be aligned to AnnData.")
    fate_index = result.fate_names.index(str(target_fate))
    score[selected_indices] = result.future_fate_contribution[:, fate_index]
    terminal = adata.obs[annotation_key].astype(str).eq(str(target_fate)).to_numpy()
    score[terminal] = 1.0
    return np.clip(score, 0.0, 1.0)


def reweight_root_transitions(
    transition_matrix,
    *,
    source_mask,
    condition_labels,
    replicate_labels,
    destination_score,
    log_shift_by_condition,
    replicate_shift_sd=0.08,
    random_state=0,
):
    """Inject a controlled condition effect without changing graph support.

    Outgoing root-cell transition probabilities are tilted toward destinations
    with high baseline target-fate probability and then renormalized. This is a
    software-validation perturbation, not a model for a particular experiment.
    """
    normalized = scCS.canonicalize_transition_matrix(transition_matrix)
    transition = normalized.matrix.tocsr(copy=True)
    source_mask = np.asarray(source_mask, dtype=bool)
    conditions = np.asarray(condition_labels, dtype=str)
    replicates = np.asarray(replicate_labels, dtype=str)
    destination_score = np.asarray(destination_score, dtype=float)
    if source_mask.shape != (transition.shape[0],):
        raise ValueError("source_mask must align to transition rows.")
    if destination_score.shape != (transition.shape[0],):
        raise ValueError("destination_score must align to transition columns.")

    rng = np.random.default_rng(random_state)
    replicate_effect = {
        replicate: float(rng.normal(0.0, replicate_shift_sd)) for replicate in np.unique(replicates)
    }
    affected = np.zeros(transition.shape[0], dtype=bool)
    for row in np.flatnonzero(source_mask):
        condition = conditions[row]
        if condition not in log_shift_by_condition:
            raise KeyError(f"Missing log shift for condition {condition!r}.")
        start, stop = transition.indptr[row], transition.indptr[row + 1]
        columns = transition.indices[start:stop]
        if len(columns) == 0:
            continue
        shift = float(log_shift_by_condition[condition]) + replicate_effect[replicates[row]]
        multipliers = np.exp(shift * destination_score[columns])
        if np.max(np.abs(multipliers - 1.0)) > 1e-12:
            affected[row] = True
        transition.data[start:stop] *= multipliers
        row_sum = float(transition.data[start:stop].sum())
        if row_sum > 0:
            transition.data[start:stop] /= row_sum
    audit = {
        "affected_root_fraction": float(np.mean(affected[source_mask])),
        "max_row_sum_error": float(
            np.max(np.abs(np.asarray(transition.sum(axis=1)).ravel() - 1.0))
        ),
        "replicate_shift_sd": float(replicate_shift_sd),
        "log_shift_by_condition": dict(log_shift_by_condition),
    }
    return transition, audit
[8]:
original_transition = scCS.get_scvelo_transition_matrix(adata)

if DEMO_MODE:
    assignments = assign_stratified_demo_design(
        adata,
        annotation_key=OBS_KEY,
        ordering_key=ORDERING_KEY,
        conditions=CONDITIONS,
        replicates_per_condition=REPLICATES_PER_CONDITION,
        condition_key=CONDITION_KEY,
        replicate_key=REPLICATE_KEY,
        random_state=SEED,
    )
    baseline_scorer = scCS.SingleScorer(
        adata,
        root=ROOT,
        branches=FATES,
        obs_key=OBS_KEY,
    )
    baseline_scorer.build_embedding(ordering_metric=ORDERING_KEY, verbose=False)
    baseline_scorer.fit(
        transition_matrix=original_transition,
        scoring_mode="future_fate",
        future_fate_options=FUTURE_OPTIONS,
        verbose=False,
    )
    baseline_result = baseline_scorer.score(write_to_adata=False, verbose=False)
    destination_score = target_destination_score(
        adata,
        baseline_result,
        annotation_key=OBS_KEY,
        target_fate=TARGET_FATE,
    )
    labels = adata.obs[OBS_KEY].astype(str)
    root_labels = {ROOT} if isinstance(ROOT, str) else set(ROOT)
    root_mask_full = labels.isin(root_labels).to_numpy()
    analysis_transition, perturbation_audit = reweight_root_transitions(
        original_transition,
        source_mask=root_mask_full,
        condition_labels=adata.obs[CONDITION_KEY].astype(str).to_numpy(),
        replicate_labels=adata.obs[REPLICATE_KEY].astype(str).to_numpy(),
        destination_score=destination_score,
        log_shift_by_condition={"control": 0.0, "treated": 1.25},
        replicate_shift_sd=0.08,
        random_state=SEED + 1,
    )
    display(pd.Series(perturbation_audit, name="value").to_frame())
else:
    required = {CONDITION_KEY, REPLICATE_KEY}
    missing = sorted(required - set(adata.obs.columns))
    if missing:
        raise KeyError(f"Missing real-study metadata columns: {missing}")
    analysis_transition = original_transition

design_balance = (
    adata.obs.groupby([CONDITION_KEY, REPLICATE_KEY], observed=True)
    .size()
    .rename("n_cells")
    .reset_index()
)
display(design_balance)
value
affected_root_fraction 1.0
max_row_sum_error 0.0
replicate_shift_sd 0.08
log_shift_by_condition {'control': 0.0, 'treated': 1.25}
condition sample_id n_cells
0 control control_R1 385
1 control control_R2 385
2 control control_R3 382
3 control control_R4 376
4 control control_R5 370
5 treated treated_R1 370
6 treated treated_R2 366
7 treated treated_R3 365
8 treated treated_R4 352
9 treated treated_R5 345

6. Construct PairScorer, preflight, and fit one pooled model

[9]:
pair = scCS.PairScorer(
    adata,
    root=ROOT,
    branches=FATES,
    obs_key=OBS_KEY,
    condition_obs_key=CONDITION_KEY,
    replicate_obs_key=REPLICATE_KEY,
    condition_order=list(CONDITIONS),
)
preflight = pair.preflight(ordering_metric=ORDERING_KEY, check_velocity=True)
preflight.display()
preflight.raise_for_errors()
pair.build_embedding(ordering_metric=ORDERING_KEY)
pair.fit(
    transition_matrix=analysis_transition,
    scoring_mode="future_fate",
    transition_scope="pooled",
    future_fate_options=FUTURE_OPTIONS,
)
results = pair.score_all_conditions(
    population="root",
    min_cells=20,
    min_replicates=4,
)
replicate_table = pair.replicate_table(results)
display(replicate_table)
replicate_table.to_csv(OUTPUT_DIR / "replicate_outcomes.csv", index=False)
level code message value
0 info furcation_valid Root and terminal annotations are valid. 2518.0
1 info root_cells Root population contains 1234 cells. 1234.0
2 info terminal_Alpha Terminal 'Alpha' contains 481 cells. 481.0
3 info terminal_Beta Terminal 'Beta' contains 591 cells. 591.0
4 info terminal_Delta Terminal 'Delta' contains 70 cells. 70.0
5 info terminal_Epsilon Terminal 'Epsilon' contains 142 cells. 142.0
6 info ordering_valid Ordering metric is finite and non-constant amo... 1.0
7 info ordering_resolution Root ordering has 1234 unique values across 12... 1.0
8 info velocity_available Velocity information is available. NaN
9 info condition_control_cells Condition 'control' contains 1898 cells. 1898.0
10 info condition_treated_cells Condition 'treated' contains 1798 cells. 1798.0
11 info condition_control_replicates Condition 'control' contains 5 biological repl... 5.0
12 info condition_treated_replicates Condition 'treated' contains 5 biological repl... 5.0
[scCS] Scientific star built for 2518 cells in 4 dimensions.
       Root radial clipping: 0.050 low / 0.050 high
       Terminal scientific coordinates: fixed equal-radius simplex vertices (radius=1.000).
scCS FutureFateScoreResult
  Furcation: root -> ['Alpha', 'Beta', 'Delta', 'Epsilon']
  Effective horizon: 64 (gamma=0.984615)
  Cells: 2518 selected; 1234 root
  Root affinity coverage: 1.000
  Root mean future-fate reach: 0.637
  Root mean future-fate entropy: 0.546
  Root mean future-fate specificity: 0.454
  Root mean reach-supported specificity: 0.291
  Root mean unresolved probability: 0.363
  Root mean signed progression: 0.037
  Root future-fate composition: Alpha=0.246, Beta=0.690, Delta=0.000, Epsilon=0.064
  Solver: direct; iterations=1; residual=1.610e-15
[scCS] 'control': 625 root cells; 5 replicates.
[scCS] 'treated': 609 root cells; 5 replicates.
condition replicate_id replicate_label n_cells n_valid_projection mean_commitment_strength mean_directional_entropy mean_commitment_entropy mean_directional_specificity mean_nearest_fate_angle_degrees ... pairwise_log_commitment_ratio::Alpha::Delta pairwise_log_commitment_ratio::Delta::Alpha pairwise_log_commitment_ratio::Alpha::Epsilon pairwise_log_commitment_ratio::Epsilon::Alpha pairwise_log_commitment_ratio::Beta::Delta pairwise_log_commitment_ratio::Delta::Beta pairwise_log_commitment_ratio::Beta::Epsilon pairwise_log_commitment_ratio::Epsilon::Beta pairwise_log_commitment_ratio::Delta::Epsilon pairwise_log_commitment_ratio::Epsilon::Delta
0 control control::control_R1 control_R1 125 125 0.635930 0.556772 0.837506 0.443228 NaN ... 6.502464 -6.502464 1.299916 -1.299916 7.496403 -7.496403 2.293855 -2.293855 -5.202548 5.202548
1 control control::control_R2 control_R2 125 125 0.632664 0.558111 0.840343 0.441889 NaN ... 6.995748 -6.995748 1.351279 -1.351279 7.972633 -7.972633 2.328164 -2.328164 -5.644469 5.644469
2 control control::control_R3 control_R3 125 125 0.636583 0.541783 0.830323 0.458217 NaN ... 6.878208 -6.878208 1.409696 -1.409696 7.919780 -7.919780 2.451268 -2.451268 -5.468512 5.468512
3 control control::control_R4 control_R4 125 125 0.631317 0.560588 0.841329 0.439412 NaN ... 6.801378 -6.801378 1.344525 -1.344525 7.745623 -7.745623 2.288769 -2.288769 -5.456854 5.456854
4 control control::control_R5 control_R5 125 125 0.633810 0.554080 0.837938 0.445920 NaN ... 7.060102 -7.060102 1.424122 -1.424122 8.031143 -8.031143 2.395162 -2.395162 -5.635980 5.635980
5 treated treated::treated_R1 treated_R1 125 125 0.644365 0.526566 0.817396 0.473434 NaN ... 6.752256 -6.752256 1.300839 -1.300839 7.893537 -7.893537 2.442121 -2.442121 -5.451417 5.451417
6 treated treated::treated_R2 treated_R2 125 125 0.638986 0.544790 0.829909 0.455210 NaN ... 6.831015 -6.831015 1.281852 -1.281852 7.881732 -7.881732 2.332568 -2.332568 -5.549164 5.549164
7 treated treated::treated_R3 treated_R3 125 125 0.640841 0.533247 0.822325 0.466753 NaN ... 6.719379 -6.719379 1.318600 -1.318600 7.804702 -7.804702 2.403923 -2.403923 -5.400779 5.400779
8 treated treated::treated_R4 treated_R4 119 119 0.636384 0.542044 0.830149 0.457956 NaN ... 6.640851 -6.640851 1.248749 -1.248749 7.710124 -7.710124 2.318022 -2.318022 -5.392102 5.392102
9 treated treated::treated_R5 treated_R5 115 115 0.638387 0.540470 0.828557 0.459530 NaN ... 6.938915 -6.938915 1.464080 -1.464080 7.982412 -7.982412 2.507577 -2.507577 -5.474835 5.474835

10 rows × 37 columns

7. Descriptive condition summaries before hypothesis testing

[10]:
summary_rows = []
for condition, condition_result in results.items():
    population = condition_result.population_summary
    row = {
        "condition": condition,
        "n_cells": condition_result.n_cells,
        "n_replicates": condition_result.n_replicates,
        "mean_future_fate_reach": np.nanmean(condition_result.commitment_strength),
        "mean_future_fate_entropy": np.nanmean(condition_result.directional_entropy),
        "mean_future_fate_specificity": np.nanmean(condition_result.directional_specificity),
        "mean_reach_supported_specificity": np.nanmean(condition_result.specific_commitment),
        "mean_signed_progression": np.nanmean(condition_result.progression_velocity),
        "mean_selected_path_coverage": np.nanmean(condition_result.transition_coverage),
        "population_balance_entropy": population.population_balance_entropy,
        "total_future_fate_mass": population.total_mass,
    }
    for fate_index, fate in enumerate(condition_result.fate_names):
        row[f"mean_affinity_{fate}"] = np.nanmean(
            condition_result.directional_affinity[:, fate_index]
        )
        row[f"mean_contribution_{fate}"] = np.nanmean(
            condition_result.commitment_contribution[:, fate_index]
        )
    summary_rows.append(row)
condition_summary = pd.DataFrame(summary_rows)
display(condition_summary)
condition_summary.to_csv(OUTPUT_DIR / "condition_summary.csv", index=False)
condition n_cells n_replicates mean_future_fate_reach mean_future_fate_entropy mean_future_fate_specificity mean_reach_supported_specificity mean_signed_progression mean_selected_path_coverage population_balance_entropy total_future_fate_mass mean_affinity_Alpha mean_contribution_Alpha mean_affinity_Beta mean_contribution_Beta mean_affinity_Delta mean_contribution_Delta mean_affinity_Epsilon mean_contribution_Epsilon
0 control 625 5 0.634061 0.554267 0.445733 0.284188 0.041153 0.997831 0.569639 396.288054 0.255614 0.161110 0.678641 0.431622 0.000272 0.000174 0.065472 0.041155
1 treated 609 5 0.639849 0.537328 0.462672 0.298845 0.033316 0.998463 0.554947 389.668187 0.240343 0.152031 0.695239 0.447012 0.000269 0.000174 0.064149 0.040632

8. Primary target-fate comparison with permutation and hierarchical bootstrap

[11]:
target_affinity_stats = pair.compare_conditions(
    results,
    condition_a=CONDITIONS[0],
    condition_b=CONDITIONS[1],
    metric="future_fate_affinity",
    fate=TARGET_FATE,
    n_permutations=9999,
    n_bootstrap=2000,
    confidence_level=0.95,
    random_state=SEED,
)
target_contribution_stats = pair.compare_conditions(
    results,
    metric="future_fate_contribution",
    fate=TARGET_FATE,
    n_permutations=9999,
    n_bootstrap=2000,
    random_state=SEED + 1,
)
display(target_affinity_stats)
display(target_contribution_stats)
[scCS] Pairwise replicate inference: 'treated' - 'control'; metric='directional_affinity'.
[scCS] Pairwise replicate inference: 'treated' - 'control'; metric='mean_commitment_contribution'.
metric metric_public metric_label fate fate_a fate_b condition_a condition_b mean_a mean_b ... permutation_method n_permutations n_replicates_a n_replicates_b pvalue_adj ci_lower ci_upper confidence_level n_bootstrap resample_cells_within_replicate
0 directional_affinity future_fate_affinity Conditional Fate Affinity (CFA) toward Beta Beta None None control treated 0.678641 0.695184 ... exact 252 5 5 0.02381 0.003381 0.029842 0.95 2000 True

1 rows × 22 columns

metric metric_public metric_label fate fate_a fate_b condition_a condition_b mean_a mean_b ... permutation_method n_permutations n_replicates_a n_replicates_b pvalue_adj ci_lower ci_upper confidence_level n_bootstrap resample_cells_within_replicate
0 mean_commitment_contribution future_fate_contribution Future-fate contribution toward Beta Beta None None control treated 0.431622 0.446928 ... exact 252 5 5 0.02381 0.003258 0.02716 0.95 2000 True

1 rows × 22 columns

9. Full fate-wise and scalar outcome battery

[12]:
fate_affinity_stats = pair.compare_conditions(
    results,
    metric="future_fate_affinity",
    n_permutations=9999,
    n_bootstrap=1000,
    random_state=SEED + 2,
)
fate_contribution_stats = pair.compare_conditions(
    results,
    metric="future_fate_contribution",
    n_permutations=9999,
    n_bootstrap=1000,
    random_state=SEED + 3,
)
scalar_tables = []
for offset, metric in enumerate(
    (
        "future_fate_reach",
        "future_fate_specificity",
        "reach_supported_specificity",
        "future_fate_entropy",
        "signed_progression",
        "selected_path_coverage",
    )
):
    table = pair.compare_conditions(
        results,
        metric=metric,
        n_permutations=9999,
        n_bootstrap=1000,
        random_state=SEED + 10 + offset,
    )
    scalar_tables.append(table)
scalar_stats = pd.concat(scalar_tables, ignore_index=True)
display(fate_affinity_stats)
display(fate_contribution_stats)
display(scalar_stats)
fate_affinity_stats.to_csv(OUTPUT_DIR / "fate_affinity_statistics.csv", index=False)
fate_contribution_stats.to_csv(OUTPUT_DIR / "fate_contribution_statistics.csv", index=False)
scalar_stats.to_csv(OUTPUT_DIR / "scalar_statistics.csv", index=False)
[scCS] Pairwise replicate inference: 'treated' - 'control'; metric='directional_affinity'.
[scCS] Pairwise replicate inference: 'treated' - 'control'; metric='mean_commitment_contribution'.
[scCS] Pairwise replicate inference: 'treated' - 'control'; metric='commitment_strength'.
[scCS] Pairwise replicate inference: 'treated' - 'control'; metric='directional_specificity'.
[scCS] Pairwise replicate inference: 'treated' - 'control'; metric='specific_commitment'.
[scCS] Pairwise replicate inference: 'treated' - 'control'; metric='directional_entropy'.
[scCS] Pairwise replicate inference: 'treated' - 'control'; metric='progression_velocity'.
[scCS] Pairwise replicate inference: 'treated' - 'control'; metric='transition_coverage'.
metric metric_public metric_label fate fate_a fate_b condition_a condition_b mean_a mean_b ... permutation_method n_permutations n_replicates_a n_replicates_b pvalue_adj ci_lower ci_upper confidence_level n_bootstrap resample_cells_within_replicate
0 directional_affinity future_fate_affinity Conditional Fate Affinity (CFA) toward Alpha Alpha None None control treated 0.255614 0.240460 ... exact 252 5 5 0.063492 -0.024313 -0.006212 0.95 1000 True
1 directional_affinity future_fate_affinity Conditional Fate Affinity (CFA) toward Beta Beta None None control treated 0.678641 0.695184 ... exact 252 5 5 0.071429 0.002450 0.029609 0.95 1000 True
2 directional_affinity future_fate_affinity Conditional Fate Affinity (CFA) toward Delta Delta None None control treated 0.000272 0.000269 ... exact 252 5 5 1.000000 -0.000082 0.000065 0.95 1000 True
3 directional_affinity future_fate_affinity Conditional Fate Affinity (CFA) toward Epsilon Epsilon None None control treated 0.065472 0.064086 ... exact 252 5 5 1.000000 -0.008398 0.006412 0.95 1000 True

4 rows × 22 columns

metric metric_public metric_label fate fate_a fate_b condition_a condition_b mean_a mean_b ... permutation_method n_permutations n_replicates_a n_replicates_b pvalue_adj ci_lower ci_upper confidence_level n_bootstrap resample_cells_within_replicate
0 mean_commitment_contribution future_fate_contribution Future-fate contribution toward Alpha Alpha None None control treated 0.161110 0.152102 ... exact 252 5 5 0.063492 -0.015379 -0.003459 0.95 1000 True
1 mean_commitment_contribution future_fate_contribution Future-fate contribution toward Beta Beta None None control treated 0.431622 0.446928 ... exact 252 5 5 0.071429 0.004137 0.027325 0.95 1000 True
2 mean_commitment_contribution future_fate_contribution Future-fate contribution toward Delta Delta None None control treated 0.000174 0.000174 ... exact 252 5 5 1.000000 -0.000050 0.000044 0.95 1000 True
3 mean_commitment_contribution future_fate_contribution Future-fate contribution toward Epsilon Epsilon None None control treated 0.041155 0.040589 ... exact 252 5 5 1.000000 -0.005454 0.003810 0.95 1000 True

4 rows × 22 columns

metric metric_public metric_label fate fate_a fate_b condition_a condition_b mean_a mean_b ... permutation_method n_permutations n_replicates_a n_replicates_b pvalue_adj ci_lower ci_upper confidence_level n_bootstrap resample_cells_within_replicate
0 commitment_strength future_fate_reach Discounted Fate Reach (DFR) None None None control treated 0.634061 0.639793 ... exact 252 5 5 0.015873 -0.000636 0.012935 0.95 1000 True
1 directional_specificity future_fate_specificity Future-Fate Specificity (FFS) None None None control treated 0.445733 0.462576 ... exact 252 5 5 0.023810 0.004753 0.029080 0.95 1000 True
2 specific_commitment reach_supported_specificity Resolved Commitment (RC) None None None control treated 0.284188 0.298742 ... exact 252 5 5 0.023810 0.003100 0.026106 0.95 1000 True
3 directional_entropy future_fate_entropy Future-fate entropy None None None control treated 0.554267 0.537424 ... exact 252 5 5 0.023810 -0.028709 -0.005731 0.95 1000 True
4 progression_velocity signed_progression Signed Ordering Flux (SOF) None None None control treated 0.041153 0.033386 ... exact 252 5 5 0.055556 -0.020465 0.004322 0.95 1000 True
5 transition_coverage selected_path_coverage Selected-path coverage None None None control treated 0.997831 0.998463 ... exact 252 5 5 0.444444 -0.001073 0.002524 0.95 1000 True

6 rows × 22 columns

10. Replicate-first effect visualizations

[13]:
fig, axes = plt.subplots(1, 3, figsize=(19, 5))
pair.plot_replicate_outcomes(
    results,
    metric="future_fate_affinity",
    fate=TARGET_FATE,
    ax=axes[0],
)
pair.plot_affinity_distributions(
    results,
    metric="future_fate_affinity",
    fate=TARGET_FATE,
    plot_type="box",
    ax=axes[1],
)
pair.plot_effects(fate_affinity_stats, ax=axes[2])
fig.tight_layout()
fig.savefig(OUTPUT_DIR / "replicate_effects.png", dpi=200, bbox_inches="tight")
plt.show()

fig, axes = plt.subplots(1, 2, figsize=(13, 5))
pair.plot_commitment_decomposition(
    results,
    fate=TARGET_FATE,
    n_bootstrap=2000,
    random_state=SEED,
    ax=axes[0],
)
pair.plot_delta_CS_heatmap(
    fate_affinity_stats,
    title="Condition effect on future-fate affinity",
    ax=axes[1],
)
fig.tight_layout()
fig.savefig(OUTPUT_DIR / "effect_decomposition_and_heatmap.png", dpi=200, bbox_inches="tight")
plt.show()
../_images/tutorials_03_pancreas_pair_scorer_24_0.png
../_images/tutorials_03_pancreas_pair_scorer_24_1.png

11. Condition-specific star grids

[14]:
for color_by, filename in (
    ("population", "star_population.png"),
    (f"future_fate_affinity:{TARGET_FATE}", "star_target_affinity.png"),
    ("future_fate_reach", "star_reach.png"),
    ("future_fate_specificity", "star_specificity.png"),
    ("reach_supported_specificity", "star_supported_specificity.png"),
    ("signed_progression", "star_signed_progression.png"),
):
    figure = pair.plot_star_grid(
        results,
        color_by=color_by,
        population="all",
        ncols=2,
        cmap="coolwarm" if color_by == "signed_progression" else None,
    )
    figure.savefig(OUTPUT_DIR / filename, dpi=200, bbox_inches="tight")
    plt.show()
../_images/tutorials_03_pancreas_pair_scorer_26_0.png
../_images/tutorials_03_pancreas_pair_scorer_26_1.png
../_images/tutorials_03_pancreas_pair_scorer_26_2.png
../_images/tutorials_03_pancreas_pair_scorer_26_3.png
../_images/tutorials_03_pancreas_pair_scorer_26_4.png
../_images/tutorials_03_pancreas_pair_scorer_26_5.png

12. Condition summaries, composition, and trajectory shifts

[15]:
fig = plt.figure(figsize=(19, 5.5))
grid = fig.add_gridspec(1, 3, width_ratios=[1.15, 1.0, 1.15])
bar_ax = fig.add_subplot(grid[0, 0])
radar_ax = fig.add_subplot(grid[0, 1], projection="polar")
progression_ax = fig.add_subplot(grid[0, 2])

pair.plot_compare_conditions_bar(
    results,
    metric="future_fate_contribution",
    ax=bar_ax,
)
pair.plot_commitment_vector_radar(
    results,
    metric="commitment_composition",
    ax=radar_ax,
)
pair.plot_trajectory_shift(results, ax=progression_ax)
fig.tight_layout()
fig.savefig(OUTPUT_DIR / "condition_summary_visuals.png", dpi=200, bbox_inches="tight")
plt.show()
../_images/tutorials_03_pancreas_pair_scorer_28_0.png

13. Heatmaps, status composition, and transition coverage

[16]:
fig, axes = plt.subplots(1, 3, figsize=(19, 5))
pair.plot_commitment_heatmap(
    results,
    metric="future_fate_contribution",
    level="condition",
    annotate=True,
    ax=axes[0],
)
pair.plot_status_composition(results, ax=axes[1])
pair.plot_transition_coverage(results, ax=axes[2])
fig.tight_layout()
fig.savefig(OUTPUT_DIR / "condition_heatmap_and_qc.png", dpi=200, bbox_inches="tight")
plt.show()
../_images/tutorials_03_pancreas_pair_scorer_30_0.png

15. Gene expression across conditions on a shared scale

[18]:
gene_candidates = ["Ins1", "Ins2", "Gcg", "Sst", "Ghrl", "Neurog3"]
genes, missing_genes = resolve_present_genes(adata, gene_candidates)
print("Resolved genes:", genes)
print("Missing genes:", missing_genes)
for gene in genes[:4]:
    figure = pair.plot_gene_expression_star_grid(
        gene,
        results,
        population="all",
        shared_scale=True,
        ncols=2,
    )
    figure.savefig(
        OUTPUT_DIR / f"gene_expression_{gene}.png",
        dpi=200,
        bbox_inches="tight",
    )
    plt.show()
Resolved genes: ['Ins1', 'Ins2', 'Gcg', 'Sst', 'Ghrl', 'Neurog3']
Missing genes: []
../_images/tutorials_03_pancreas_pair_scorer_34_1.png
../_images/tutorials_03_pancreas_pair_scorer_34_2.png
../_images/tutorials_03_pancreas_pair_scorer_34_3.png
../_images/tutorials_03_pancreas_pair_scorer_34_4.png

16. Optional transition-scope sensitivity

[19]:
if RUN_SCOPE_SENSITIVITY:
    scope_tables = []
    for scope in ("pooled", "condition", "replicate"):
        scope_pair = scCS.PairScorer(
            adata,
            root=ROOT,
            branches=FATES,
            obs_key=OBS_KEY,
            condition_obs_key=CONDITION_KEY,
            replicate_obs_key=REPLICATE_KEY,
            condition_order=list(CONDITIONS),
        )
        scope_pair.build_embedding(ordering_metric=ORDERING_KEY, verbose=False)
        scope_pair.fit(
            transition_matrix=analysis_transition,
            transition_scope=scope,
            scoring_mode="future_fate",
            future_fate_options=FUTURE_OPTIONS,
            verbose=False,
        )
        table = scope_pair.transition_scope_summary(population="root")
        table["transition_scope"] = scope
        scope_tables.append(table)
    scope_summary = pd.concat(scope_tables, ignore_index=True)
    display(scope_summary)
    scope_summary.to_csv(OUTPUT_DIR / "transition_scope_sensitivity.csv", index=False)
else:
    print("Set RUN_SCOPE_SENSITIVITY=True to compare pooled/blocked graphs.")
Set RUN_SCOPE_SENSITIVITY=True to compare pooled/blocked graphs.

17. Optional fail-closed mixed-model sensitivity

[20]:
if RUN_MIXED_MODEL_SENSITIVITY:
    mixed = pair.fit_mixed_model(
        metric="future_fate_affinity",
        fate=TARGET_FATE,
        results=results,
        on_invalid="return",
    )
    display(mixed)
    mixed.to_csv(OUTPUT_DIR / "mixed_model_sensitivity.csv", index=False)
else:
    print("Permutation and hierarchical bootstrap are the primary inference.")
Permutation and hierarchical bootstrap are the primary inference.

18. Export analysis objects and statistical tables

[21]:
pair.result.write_to_adata(adata)
adata.write_h5ad(OUTPUT_DIR / "pair_scorer_analysis.h5ad")
target_affinity_stats.to_csv(OUTPUT_DIR / "primary_target_affinity_test.csv", index=False)
target_contribution_stats.to_csv(
    OUTPUT_DIR / "primary_target_contribution_test.csv",
    index=False,
)
print("Saved outputs to", OUTPUT_DIR.resolve())
Saved outputs to /home/emil/notebooks/08-tutorials/tutorial_outputs/pancreas_pair

19. Interpretation and real-study adaptation

In the controlled demonstration, the expected primary effect is increased future Beta affinity/contribution in treated. Reach or signed progression can also change and must be reported rather than assumed constant. Alpha, Delta, and Epsilon remain biologically complex branches.

For real data:

  1. set DEMO_MODE=False;

  2. provide genuine condition and independent replicate columns;

  3. use the original velocity transition matrix without controlled reweighting;

  4. verify condition balance, transition-scope assumptions, and replicate counts;

  5. report effect sizes, raw and adjusted p-values, replicate counts, and confidence intervals;

  6. do not treat cells as biological replicates.