use max function

Author: Christian-B

spynnaker/spynnaker_plotting.py

@@ -164,7 +164,7 @@ def heat_plot_numpy(axes: Axes, data: NDArray, label: str = '',
     neurons = data[:, 0].astype(numpy.uint32)
     times = data[:, 1].astype(numpy.uint32)
     values = data[:, 2]
-    info_array = np.empty((max(neurons) + 1, max(times) + 1))
+    info_array = np.empty((neurons.max() + 1, times.max() + 1))
     info_array[:] = np.nan
     info_array[neurons, times] = values
     _heat_plot(axes, info_array, label=label, **options)