Add minimal tests for TH1F and TH2F

tests/test_root.py

@@ -1,7 +1,39 @@
+import numpy as np
 import pytest
+from pytest import approx
+
+from uhi.numpy_plottable import ensure_plottable_histogram
 
 ROOT = pytest.importorskip("ROOT")
 
 
 def test_root_imported() -> None:
     assert ROOT.TString("hi") == "hi"
+
+
+def test_root_th1f_convert() -> None:
+    th = ROOT.TH1F("h1", "h1", 50, -2.5, 2.5)
+    th.FillRandom("gaus", 10000)
+    h = ensure_plottable_histogram(th)
+    assert all(th.GetBinContent(i + 1) == approx(iv) for i, iv in enumerate(h.values()))
+    assert all(
+        th.GetBinError(i + 1) == approx(ie)
+        for i, ie in enumerate(np.sqrt(h.variances()))  # type: ignore
+    )
+
+
+def test_root_th2f_convert() -> None:
+    th = ROOT.TH2F("h2", "h2", 50, -2.5, 2.5, 50, -2.5, 2.5)
+    _ = ROOT.TF2("xyg", "xygaus", -2.5, 2.5, -2.5, 2.5)
+    th.FillRandom("xyg", 10000)
+    h = ensure_plottable_histogram(th)
+    assert all(
+        th.GetBinContent(i + 1, j + 1) == approx(iv)
+        for i, row in enumerate(h.values())
+        for j, iv in enumerate(row)
+    )
+    assert all(
+        th.GetBinError(i + 1, j + 1) == approx(ie)
+        for i, row in enumerate(np.sqrt(h.variances()))  # type: ignore
+        for j, ie in enumerate(row)
+    )