feat(pynml): do not import plotters if mpl is not already imported

pyneuroml/analysis/__init__.py

@@ -8,6 +8,7 @@
 from pyneuroml.lems.LEMSSimulation import LEMSSimulation
 from pyneuroml.lems import generate_lems_file_for_neuroml
 from pyneuroml.utils.plot import get_next_hex_color
+from pyneuroml.plot import generate_plot
 import neuroml as nml
 from pyelectro.analysis import max_min
 from pyelectro.analysis import mean_spike_frequency
@@ -381,7 +382,7 @@ def generate_current_vs_frequency_curve(
                 iv_results[stims[i]] = v_end
 
     if plot_voltage_traces:
-        traces_ax = pynml.generate_plot(
+        traces_ax = generate_plot(
             times_results,
             volts_results,
             "Membrane potential traces for: %s" % nml2_file,
@@ -403,7 +404,7 @@ def generate_current_vs_frequency_curve(
         stims = sorted(if_results.keys())
         stims_pA = [ii * 1000 for ii in stims]
         freqs = [if_results[s] for s in stims]
-        if_ax = pynml.generate_plot(
+        if_ax = generate_plot(
             [stims_pA],
             [freqs],
             "Firing frequency versus injected current for: %s" % nml2_file,
@@ -455,7 +456,7 @@ def generate_current_vs_frequency_curve(
             xs[-1].append(stim * 1000)
             ys[-1].append(iv_results[stim])
 
-        iv_ax = pynml.generate_plot(
+        iv_ax = generate_plot(
             xs,
             ys,
             "V at %sms versus I below threshold for: %s" % (end_stim, nml2_file),
@@ -621,7 +622,7 @@ def analyse_spiketime_vs_dt(
         markers.append("")
         colors.append("k")
 
-    pynml.generate_plot(
+    generate_plot(
         spxs,
         spys,
         "Spike times vs dt",
@@ -635,7 +636,7 @@ def analyse_spiketime_vs_dt(
     )
 
     if verbose:
-        pynml.generate_plot(
+        generate_plot(
             xs,
             ys,
             "Membrane potentials in %s for %s" % (simulator, dts),

pyneuroml/pynml.py

@@ -45,10 +45,31 @@
 import neuroml.loaders as loaders
 import neuroml.writers as writers
 
-# to maintain API compatibility:
-# so that existing scripts that use: from pynml import generate_plot
-# continue to work
-from pyneuroml.plot import generate_plot, generate_interactive_plot  # noqa
+logger = logging.getLogger(__name__)
+logger.setLevel(logging.INFO)
+
+matplotlib_imported = False
+for k in sys.modules.keys():
+    if "matplotlib" in k:
+        matplotlib_imported = True
+        break
+if matplotlib_imported is True:
+    # to maintain API compatibility:
+    # so that existing scripts that use: from pynml import generate_plot
+    # continue to work
+    from pyneuroml.plot import generate_plot, generate_interactive_plot  # noqa
+else:
+    logger.warning("Matplotlib has not been imported, not importing plotting functions")
+    logger.warning("Please import these explicitly from pyneuroml.plot")
+    warnings.warn(
+        """
+        Please note that these plotting methods will be removed from the pynml
+        module in the future. Please import plotting methods expliclitly from
+        the pyneuroml.plot sub module.
+        """,
+        FutureWarning,
+        stacklevel=2,
+    )
 
 DEFAULTS = {
     "v": False,
@@ -58,9 +79,6 @@
 
 lems_model_with_units = None
 
-logger = logging.getLogger(__name__)
-logger.setLevel(logging.INFO)
-
 version_string = "pyNeuroML v{} (libNeuroML v{}, jNeuroML v{})".format(
     __version__, neuroml.__version__, JNEUROML_VERSION
 )