Article Outline
Example Python program clickplot (1).py For Python version 2.x. To test your Python version use:
python --versionModules
- from matplotlib import pyplot
- import numpy as np
import clickplot
- import warnings
Classes
- class ClickPlot:
Methods
- def init(self, fig=None):
- def clearMarker(self):
- def getSubPlotNr(self, event):
- def sanityCheck(self):
- def show(self):
- def selectSubPlot(self, i):
- def onClick(self, event):
- def onKey(self, event):
- def onRelease(self, event):
- def onScroll(self, event):
- def showClickPlot(fig=None):
Code
Python example
#!/usr/bin/env python
#-*- coding:utf-8 -*-
from matplotlib import pyplot
import numpy as np
class ClickPlot:
"""
A clickable matplotlib figure
Usage:
>>> import clickplot
>>> retval = clickplot.showClickPlot()
>>> print retval['subPlot']
>>> print retval['x']
>>> print retval['y']
>>> print retval['comment']
See an example below
"""
def __init__(self, fig=None):
"""
Constructor
Arguments:
fig -- a matplotlib figure
"""
if fig != None:
self.fig = fig
else:
self.fig = pyplot.get_current_fig_manager().canvas.figure
self.nSubPlots = len(self.fig.axes)
self.dragFrom = None
self.comment = '0'
self.markers = []
self.retVal = {'comment' : self.comment, 'x' : None, 'y' : None,
'subPlot' : None}
self.sanityCheck()
self.supTitle = pyplot.suptitle("comment: %s" % self.comment)
self.fig.canvas.mpl_connect('button_press_event', self.onClick)
self.fig.canvas.mpl_connect('button_release_event', self.onRelease)
self.fig.canvas.mpl_connect('scroll_event', self.onScroll)
self.fig.canvas.mpl_connect('key_press_event', self.onKey)
def clearMarker(self):
"""Remove marker from retVal and plot"""
self.retVal['x'] = None
self.retVal['y'] = None
self.retVal['subPlot'] = None
for i in range(self.nSubPlots):
subPlot = self.selectSubPlot(i)
for marker in self.markers:
if marker in subPlot.lines:
subPlot.lines.remove(marker)
self.markers = []
self.fig.canvas.draw()
def getSubPlotNr(self, event):
"""
Get the nr of the subplot that has been clicked
Arguments:
event -- an event
Returns:
A number or None if no subplot has been clicked
"""
i = 0
axisNr = None
for axis in self.fig.axes:
if axis == event.inaxes:
axisNr = i
break
i += 1
return axisNr
def sanityCheck(self):
"""Prints some warnings if the plot is not correct"""
subPlot = self.selectSubPlot(0)
minX = subPlot.dataLim.min[0]
maxX = subPlot.dataLim.max[0]
for i in range(self.nSubPlots):
subPlot = self.selectSubPlot(i)
_minX = subPlot.dataLim.min[0]
_maxX = subPlot.dataLim.max[0]
if abs(_minX-minX) != 0 or (_maxX-maxX) != 0:
import warnings
warnings.warn('Not all subplots have the same X-axis')
def show(self):
"""
Show the plot
Returns:
A dictionary with information about the response
"""
pyplot.show()
self.retVal['comment'] = self.comment
return self.retVal
def selectSubPlot(self, i):
"""
Select a subplot
Arguments:
i -- the nr of the subplot to select
Returns:
A subplot
"""
pyplot.subplot('%d1%d' % (self.nSubPlots, i+1))
return self.fig.axes[i]
def onClick(self, event):
"""
Process a mouse click event. If a mouse is right clicked within a
subplot, the return value is set to a (subPlotNr, xVal, yVal) tuple and
the plot is closed. With right-clicking and dragging, the plot can be
moved.
Arguments:
event -- a MouseEvent event
"""
subPlotNr = self.getSubPlotNr(event)
if subPlotNr == None:
return
if event.button == 1:
self.clearMarker()
for i in range(self.nSubPlots):
subPlot = self.selectSubPlot(i)
marker = pyplot.axvline(event.xdata, 0, 1, linestyle='--', \
linewidth=2, color='gray')
self.markers.append(marker)
self.fig.canvas.draw()
self.retVal['subPlot'] = subPlotNr
self.retVal['x'] = event.xdata
self.retVal['y'] = event.ydata
else:
# Start a dragFrom
self.dragFrom = event.xdata
def onKey(self, event):
"""
Handle a keypress event. The plot is closed without return value on
enter. Other keys are used to add a comment.
Arguments:
event -- a KeyEvent
"""
if event.key == 'enter':
pyplot.close()
return
if event.key == 'escape':
self.clearMarker()
return
if event.key == 'backspace':
self.comment = self.comment[:-1]
elif len(event.key) == 1:
self.comment += event.key
self.supTitle.set_text("comment: %s" % self.comment)
event.canvas.draw()
def onRelease(self, event):
"""
Handles a mouse release, which causes a move
Arguments:
event -- a mouse event
"""
if self.dragFrom == None or event.button != 3:
return
dragTo = event.xdata
dx = self.dragFrom - dragTo
for i in range(self.nSubPlots):
subPlot = self.selectSubPlot(i)
xmin, xmax = subPlot.get_xlim()
xmin += dx
xmax += dx
subPlot.set_xlim(xmin, xmax)
event.canvas.draw()
def onScroll(self, event):
"""
Process scroll events. All subplots are scrolled simultaneously
Arguments:
event -- a MouseEvent
"""
for i in range(self.nSubPlots):
subPlot = self.selectSubPlot(i)
xmin, xmax = subPlot.get_xlim()
dx = xmax - xmin
cx = (xmax+xmin)/2
if event.button == 'down':
dx *= 1.1
else:
dx /= 1.1
_xmin = cx - dx/2
_xmax = cx + dx/2
subPlot.set_xlim(_xmin, _xmax)
event.canvas.draw()
def showClickPlot(fig=None):
"""
Show a pyplot and return a dictionary with information
Returns:
A dictionary with the following keys:
'subPlot' : the subplot or None if no marker has been set
'x' : the X coordinate of the marker (or None)
'y' : the Y coordinate of the marker (or None)
'comment' : a comment string
"""
cp = ClickPlot(fig)
return cp.show()
if __name__ == '__main__':
xData = np.linspace(0, 4*np.pi, 100)
yData1 = np.cos(xData)
yData2 = np.sin(xData)
fig = pyplot.figure()
subPlot1 = fig.add_subplot('211')
pyplot.plot(xData, yData1, figure=fig)
subPlot2 = fig.add_subplot('212')
pyplot.plot(xData, yData2, figure=fig)
# Show the clickplot and print the return values
retval = showClickPlot()
print 'Comment = %s' % retval['comment']
if retval['subPlot'] == None:
print 'No subplot selected'
else:
print 'You clicked in subplot %(subPlot)d at (%(x).3f, %(y).3f)' \
% retvalUseful Links
- Articles: https://python-commandments.org/
- Python shell: https://bsdnerds.org/learn-python/
- Tutorial: https://pythonprogramminglanguage.com/