Fix issue #263 (plotting displays)

VERSION-HISTORY.md

@@ -3,6 +3,7 @@ This file is a version history of blimpy amendments, beginning with version 2.0.
 <br>
 |    Date    | Version | Contents |
 | :--: | :--: | :-- |
+| 2022-04-19 | 2.0.40 | Fixed blimpy to show plots when the display supports it (issue #263). |
 | 2022-03-30 | 2.0.39 | examine_h5 in hdf_reader.py is loading too much data (issue #261). |
 | | | Version/Release 2.0.38 cannot be used. |
 | 2022-02-03 | 2.0.37 | Having trouble with publishing on pypi. Seems to be stuck on blimpy v2.0.35. |

blimpy/plotting/config.py

@@ -1,19 +1,61 @@
+"""
+Blimpy Plotting Configuration
+This file is imported by the other plotting source files and blimpy/waterfall.py.
+
+matplotlib backends info:
+https://matplotlib.org/3.5.0/users/explain/backends.html#:~:text=By%20default%2C%20Matplotlib%20should%20automatically,to%20worry%20about%20the%20backend.
+"""
 import os
 import numpy as np
-
-# Check if $DISPLAY is set (for handling plotting on remote machines with no X-forwarding)
 import matplotlib
 
-if 'DISPLAY' in os.environ.keys():
-    import pylab as plt
-else:
-    matplotlib.use('Agg')
-    import pylab as plt
+# Define plt for caller.
+import matplotlib.pyplot as plt
+plt.rcParams['axes.formatter.useoffset'] = False
 
+# Define NullFormatter for caller.
 from matplotlib.ticker import NullFormatter
 
-plt.rcParams['axes.formatter.useoffset'] = False
+#Define some constants for caller.
+MAX_PLT_POINTS      = 65536                  # Max number of points in matplotlib plot
+MAX_IMSHOW_POINTS   = (8192, 4096)           # Max number of points in imshow plot
 
 
-MAX_PLT_POINTS      = 65536                  # Max number of points in matplotlib plot
-MAX_IMSHOW_POINTS   = (8192, 4096)           # Max number of points in imshow plot
+def ok_to_show():
+    """
+    Tell caller if the DISPLAY environment variable is set
+    and therefore if plt.show() can be executed.
+
+    Parameters
+    ----------
+    None.
+
+    Returns
+    -------
+    bool
+        Can plt.show() be executed (True/False)?
+
+    """
+    display = os.environ.get("DISPLAY", "empty")
+    if display == "empty":
+        print("blimpy plotting config.py setup_plotting_backend: DISPLAY is *empty*")
+        return False
+    print(f"blimpy plotting config.py setup_plotting_backend: DISPLAY is {display}")
+    return True
+
+
+def print_plotting_backend(arg_context):
+    """ Show which matplotlib backend is in use."""
+    ok_to_show()
+    print(f"blimpy plotting config.py ({arg_context}): matplotlib backend is {matplotlib.get_backend()}")
+
+
+def get_mpl_backend():
+    return matplotlib.get_backend()
+
+
+def set_mpl_backend(backend):
+    matplotlib.use(backend)
+
+
+print_plotting_backend("import config.py definitions")

blimpy/plotting/plot_utils.py

@@ -1,5 +1,3 @@
-from .config import *
-
 def calc_extent(self, plot_f=None, plot_t=None, MJD_time=False):
     """ Setup plotting edges.
     """

blimpy/plotting/plot_waterfall.py

@@ -13,7 +13,6 @@ def plot_waterfall(wf, f_start=None, f_stop=None, if_id=0, logged=True, cb=True,
         cb (bool): for plotting the colorbar
         kwargs: keyword args to be passed to matplotlib imshow()
     """
-
     plot_f, plot_data = wf.grab_data(f_start, f_stop, if_id)
 
     # imshow does not support int8, so convert to floating point

blimpy/waterfall.py

@@ -23,8 +23,14 @@
 import numpy as np
 import six
 
+SHOWING_BACKEND = False
+
 from blimpy.io import file_wrapper as fw
-from .plotting import *
+from .plotting.config import *
+from .plotting import plot_all, plot_kurtosis, plot_spectrum_min_max, plot_spectrum, plot_time_series, plot_waterfall
+MPL_BACKEND = get_mpl_backend()
+if SHOWING_BACKEND:
+    print(f"after importing plot_all etc: {MPL_BACKEND}")
 
 from astropy.time import Time
 from astropy import units as u
@@ -377,6 +383,10 @@ def cmd_tool(args=None):
 
     from argparse import ArgumentParser
 
+    set_mpl_backend(MPL_BACKEND)
+    if SHOWING_BACKEND:
+        print_plotting_backend("entered cmd_tool")
+
     parser = ArgumentParser(description="Command line utility for reading and plotting blimpy files.")
 
     parser.add_argument('filename', type=str,
@@ -433,15 +443,15 @@ def cmd_tool(args=None):
 
     # And if we want to plot data, then plot data.
     if not info_only:
-        from .plotting.config import plt
-
-        print('')
 
         if parse_args.blank_dc:
             logger.info("Blanking DC bin")
             n_coarse_chan = fil.calc_n_coarse_chan()
             fil.blank_dc(n_coarse_chan)
 
+        if SHOWING_BACKEND:
+            print_plotting_backend("before plotting")
+
         if parse_args.what_to_plot == "s":
             plt.figure("Spectrum", figsize=(8, 6))
             fil.plot_spectrum(logged=True, f_start=parse_args.f_start, f_stop=parse_args.f_stop, t='all')
@@ -467,8 +477,10 @@ def cmd_tool(args=None):
         if parse_args.plt_filename != '':
             plt.savefig(parse_args.plt_filename)
 
+        if SHOWING_BACKEND:
+            print_plotting_backend("before plt.show")
         if not parse_args.save_only:
-            if 'DISPLAY' in os.environ.keys():
+            if ok_to_show():
                 plt.show()
             else:
                 logger.warning("No $DISPLAY available.")
@@ -501,4 +513,4 @@ def cmd_tool(args=None):
 
 
 if __name__ == "__main__":
-    cmd_tool()
+    cmd_tool()

setup.py

@@ -3,7 +3,7 @@
 """
 from setuptools import setup, find_packages
 
-__version__ = '2.0.39'
+__version__ = '2.0.40'
 
 with open("README.md", "r") as fh:
     long_description = fh.read()

tests/test_waterfall.py

@@ -9,6 +9,7 @@
 OUTDIR = os.path.dirname(voyager_h5) + "/"
 
 def test_info():
+    print("\n===== test_info")
     a = bl.Waterfall(voyager_h5)
     print(a)
     a.info()
@@ -26,6 +27,7 @@ def test_info():
     del a
 
 def test_get_freqs():
+    print("\n===== test_get_freqs")
     wf = bl.Waterfall(voyager_h5)
     freqs = wf.container.populate_freqs()
     sum1 = np.sum(freqs)
@@ -45,8 +47,8 @@ def test_get_freqs():
     assert np.isclose(last_1, last_2, rtol=0.0001)
 
 def test_cmdline():
-    # Plots
-    
+    print("\n===== test_cmdline")
+
     args = [voyager_h5, '-S', '-p', 'w', '-s', OUTDIR + 'test.png']
     cmd_tool(args)
 
@@ -101,17 +103,20 @@ def test_cmdline():
         os.remove(OUTDIR + 'test.fil')
 
 def test_cmd_arguments():
+    print("\n===== test_cmd_arguments")
     args = [voyager_h5, '-H', '-F', '-o', OUTDIR + 'test.fil']
     with pytest.raises(ValueError):
         cmd_tool(args)
 
 def test_neg_blank_dc():
+    print("\n===== test_neg_blank_dc")
     wf = bl.Waterfall(voyager_h5)
     wf.blank_dc(0)
     wf.blank_dc(1.1)
     del wf
 
 def test_get_chunk_dimensions():
+    print("\n===== test_get_chunk_dimensions")
     wf = bl.Waterfall(voyager_h5)
 
     wf.header['foff'] = 0.99e-5
@@ -131,12 +136,14 @@ def test_get_chunk_dimensions():
     del wf
 
 def test_neg_info_foff():
+    print("\n===== test_neg_info_foff")
     wf = bl.Waterfall(voyager_h5)
     wf.header['foff'] = -1
     wf.info()
     del wf
 
 def test_no_filename():
+    print("\n===== test_no_filename")
     header = { "banana": "is a fruit" }
     data = np.arange(1, 11)
     class Puddle(bl.Waterfall):