Fix IndexError during test_visualization_with__t_inf (#209)

Closes #206

Author: dweindl

petab/visualize/plotter.py

@@ -116,6 +116,8 @@ def generate_lineplot(
             if plotTypeData == REPLICATE:
                 replicates = np.stack(
                     measurements_to_plot.data_to_plot.repl.values)
+                if replicates.ndim == 1:
+                    replicates = np.expand_dims(replicates, axis=1)
 
                 # plot first replicate
                 p = ax.plot(
@@ -544,6 +546,8 @@ def _line_plot_at_t_inf(
                 p = None
                 if plotTypeData == REPLICATE:
                     replicates = measurements_data_to_plot_inf.repl
+                    if replicates.ndim == 0:
+                        replicates = np.expand_dims(replicates, axis=0)
 
                     # plot first replicate
                     p = ax_inf.plot(
@@ -587,6 +591,8 @@ def _line_plot_at_t_inf(
 
             if plotTypeData == REPLICATE:
                 replicates = simulations_data_to_plot_inf.repl
+                if replicates.ndim == 0:
+                    replicates = np.expand_dims(replicates, axis=0)
 
                 # plot first replicate
                 p = ax_inf.plot(