Vis: fix replicates sorting (#232)

Fixed ordering of replicates by timepoints

Author: plakrisenko

petab/visualize/plotter.py

@@ -123,12 +123,23 @@ def generate_lineplot(
                 replicates = np.stack(
                     measurements_to_plot.data_to_plot.repl.values
                 )
+                # sorts according to ascending order of conditions
+                cond, replicates = zip(
+                    *sorted(
+                        zip(
+                            measurements_to_plot.conditions,
+                            replicates
+                        )
+                    )
+                )
+                replicates = np.stack(replicates)
+
                 if replicates.ndim == 1:
                     replicates = np.expand_dims(replicates, axis=1)
 
                 # plot first replicate
                 p = ax.plot(
-                    measurements_to_plot.conditions,
+                    cond,
                     replicates[:, 0],
                     linestyle="-.",
                     marker="x",
@@ -138,7 +149,7 @@ def generate_lineplot(
 
                 # plot other replicates with the same color
                 ax.plot(
-                    measurements_to_plot.conditions,
+                    cond,
                     replicates[:, 1:],
                     linestyle="-.",
                     marker="x",