graphstats: Add support for interactive graphs

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

docs/Debugging.md

@@ -147,7 +147,7 @@ sudo apt-get install python-matplotlib
 Then graphs can be produced with:
 
 ```
-~/klipper/scripts/graphstats.py /tmp/klippy.log loadgraph.png
+~/klipper/scripts/graphstats.py /tmp/klippy.log -o loadgraph.png
 ```
 
 One can then view the resulting **loadgraph.png** file.

scripts/graphstats.py

@@ -1,14 +1,11 @@
 #!/usr/bin/env python2
 # Script to parse a logging file, extract the stats, and graph them
 #
-# Copyright (C) 2016-2018  Kevin O'Connor <kevin@koconnor.net>
+# Copyright (C) 2016-2019  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
 import optparse, datetime
 import matplotlib
-matplotlib.use('Agg')
-import matplotlib.pyplot, matplotlib.dates, matplotlib.font_manager
-import matplotlib.ticker
 
 MAXBANDWIDTH=25000.
 MAXBUFFER=2.
@@ -53,6 +50,12 @@ def parse_log(logname, mcu):
     f.close()
     return out
 
+def setup_matplotlib(output_to_file):
+    if output_to_file:
+        matplotlib.use('Agg')
+    import matplotlib.pyplot, matplotlib.dates, matplotlib.font_manager
+    import matplotlib.ticker
+
 def find_print_restarts(data):
     runoff_samples = {}
     last_runoff_start = last_buffer_time = last_sampletime = 0.
@@ -81,7 +84,7 @@ def find_print_restarts(data):
                      for sampletime in samples if not stall}
     return sample_resets
 
-def plot_mcu(data, maxbw, outname):
+def plot_mcu(data, maxbw):
     # Generate data for plot
     basetime = lasttime = data[0]['#sampletime']
     lastbw = float(data[0]['bytes_write']) + float(data[0]['bytes_retransmit'])
@@ -131,10 +134,9 @@ def plot_mcu(data, maxbw, outname):
     ax1.legend(loc='best', prop=fontP)
     ax1.xaxis.set_major_formatter(matplotlib.dates.DateFormatter('%H:%M'))
     ax1.grid(True)
-    fig.set_size_inches(8, 6)
-    fig.savefig(outname)
+    return fig
 
-def plot_frequency(data, outname, mcu):
+def plot_frequency(data, mcu):
     all_keys = {}
     for d in data:
         all_keys.update(d)
@@ -167,10 +169,9 @@ def plot_frequency(data, outname, mcu):
     ax1.xaxis.set_major_formatter(matplotlib.dates.DateFormatter('%H:%M'))
     ax1.yaxis.set_major_formatter(matplotlib.ticker.FormatStrFormatter('%d'))
     ax1.grid(True)
-    fig.set_size_inches(8, 6)
-    fig.savefig(outname)
+    return fig
 
-def plot_temperature(data, outname, heater):
+def plot_temperature(data, heater):
     temp_key = heater + ':' + 'temp'
     target_key = heater + ':' + 'target'
     pwm_key = heater + ':' + 'pwm'
@@ -201,32 +202,45 @@ def plot_temperature(data, outname, heater):
     ax1.legend(loc='best', prop=fontP)
     ax1.xaxis.set_major_formatter(matplotlib.dates.DateFormatter('%H:%M'))
     ax1.grid(True)
-    fig.set_size_inches(8, 6)
-    fig.savefig(outname)
+    return fig
 
 def main():
-    usage = "%prog [options] <logfile> <outname>"
+    # Parse command-line arguments
+    usage = "%prog [options] <logfile>"
     opts = optparse.OptionParser(usage)
     opts.add_option("-f", "--frequency", action="store_true",
                     help="graph mcu frequency")
+    opts.add_option("-o", "--output", type="string", dest="output",
+                    default=None, help="filename of output graph")
     opts.add_option("-t", "--temperature", type="string", dest="heater",
                     default=None, help="graph heater temperature")
     opts.add_option("-m", "--mcu", type="string", dest="mcu", default=None,
                     help="limit stats to the given mcu")
     options, args = opts.parse_args()
-    if len(args) != 2:
+    if len(args) != 1:
         opts.error("Incorrect number of arguments")
-    logname, outname = args
+    logname = args[0]
+
+    # Parse data
     data = parse_log(logname, options.mcu)
     if not data:
         return
+
+    # Draw graph
+    setup_matplotlib(options.output is not None)
     if options.heater is not None:
-        plot_temperature(data, outname, options.heater)
-        return
-    if options.frequency:
-        plot_frequency(data, outname, options.mcu)
-        return
-    plot_mcu(data, MAXBANDWIDTH, outname)
+        fig = plot_temperature(data, options.heater)
+    elif options.frequency:
+        fig = plot_frequency(data, options.mcu)
+    else:
+        fig = plot_mcu(data, MAXBANDWIDTH)
+
+    # Show graph
+    if options.output is None:
+        matplotlib.pyplot.show()
+    else:
+        fig.set_size_inches(8, 6)
+        fig.savefig(options.output)
 
 if __name__ == '__main__':
     main()