Fix axis names (#2462)

* Always add axis label names if argument is specified
* Consistent plotting style
* chlog

---------

Co-authored-by: Jirka <[email protected]>

CHANGELOG.md

@@ -30,7 +30,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
--
+- Fixed axis names with Precision-Recall curve ([#2462](https://github.com/Lightning-AI/torchmetrics/pull/2462))
 
 
 ## [1.3.2] - 2024-03-18

src/torchmetrics/utilities/plot.py

@@ -307,9 +307,6 @@ def plot_curve(
     if isinstance(x, Tensor) and isinstance(y, Tensor) and x.ndim == 1 and y.ndim == 1:
         label = f"AUC={score.item():0.3f}" if score is not None else None
         ax.plot(x.detach().cpu(), y.detach().cpu(), linestyle="-", linewidth=2, label=label)
-        if label_names is not None:
-            ax.set_xlabel(label_names[0])
-            ax.set_ylabel(label_names[1])
         if label is not None:
             ax.legend()
     elif (isinstance(x, list) and isinstance(y, list)) or (
@@ -318,12 +315,15 @@ def plot_curve(
         for i, (x_, y_) in enumerate(zip(x, y)):
             label = f"{legend_name}_{i}" if legend_name is not None else str(i)
             label += f" AUC={score[i].item():0.3f}" if score is not None else ""
-            ax.plot(x_.detach().cpu(), y_.detach().cpu(), label=label)
+            ax.plot(x_.detach().cpu(), y_.detach().cpu(), linestyle="-", linewidth=2, label=label)
             ax.legend()
     else:
         raise ValueError(
             f"Unknown format for argument `x` and `y`. Expected either list or tensors but got {type(x)} and {type(y)}."
         )
+    if label_names is not None:
+        ax.set_xlabel(label_names[0])
+        ax.set_ylabel(label_names[1])
     ax.grid(True)
     ax.set_title(name)