Content

Parsing of input parameters

Parsing "on knees"

import sys
import os

def get_input_parameters() :
    nargs = len(sys.argv)
    print 'sys.argv[0]: ', sys.argv[0]
    print 'nargs: ', nargs
    # Then do something with arguments...

Use OptionParser

from optparse import OptionParser

def input_option_parser() :

    def_fname = 'spec-xppi0412-r0060-20120507-125420.198726277.txt'
    def_cols = 100

    parser = OptionParser(description='Process optional input parameters.', usage = "usage: %prog [options]")
    parser.add_option('-f', '--fname', dest='fname', default=def_fname, action='store', type='string', help='input file name')
    parser.add_option('-c', '--cols', dest='cols', default=def_cols, action='store', type='int', help='number of columns in the image array')
    parser.add_option('-v', dest='verbose', action='store_true',  help='set flag to print more details',  default=True)
    parser.add_option('-q', dest='verbose', action='store_false', help='set flag to print less details')
    (opts, args) = parser.parse_args()

    print 'opts:',opts
    print 'args:',args

    return (opts, args)

Manipulation with directories and files

Access to files in the derectory

def getListOfFilesInDir(dirname) :
    return os.listdir(dirname)

def printListOfFilesInDir(dirname) :
    print 'List of files in the dir.', dirname
    for name in os.listdir(dirname) :
        print name
    print '\n'

Parsing the pathname

        root, ext = os.path.splitext(path) # i.e. path='root-part.tail-part'
        basename  = os.path.basename(path)
        dirname   = os.path.dirname(path)
        lexist    = os.path.lexists(path)
        isfile    = os.path.isfile(path)
        isdir     = os.path.isdir(path)
        head, tail= os.path.split(path)    # i.e. path='head-part/tail-part'
...

http://docs.python.org/library/os.path.html

Useful string parsing options

http://docs.python.org/library/string.html

    string.rsplit(str, sep, maxsplit)
    string.capitalize(word)
    string.lower(s)
    start = string.find(symbolic_string, pattern)
    pattern_length = len(pattern)

http://docs.python.org/library/parser.html?

Or use more shorter methods for str object:
http://docs.python.org/library/stdtypes.html, for example:

    par_str = line[pos_eq+1:].strip(' ').rstrip('\n')

Python - useful references

Built-in functions

http://docs.python.org/library/functions.html

setattr - gives dynamic variables in python

http://docs.python.org/library/functions.html#setattr

PyQt4

Open/close/move other GUI window

Try to close window if its object exists, othervise - open:

    def processConfigPars(self):
        print 'processConfigPars'
        try :
            cp.confpars.guiconfigparameters.close()
        except : # AttributeError: #NameError 
            cp.confpars.guiconfigparameters = guiconfigpars.GUIConfigParameters()
            cp.confpars.guiconfigparameters.move(self.pos().__add__(QtCore.QPoint(100,330))) # window offset
            # or use self.parentWidget().pos() for combined widgets:
            # cp.guifilebrowser.move(self.parentWidget().pos().__add__(QtCore.QPoint(240,40)))
            cp.confpars.guiconfigparameters.show()

Sometime it looks like the window does not want to move in specified position...
In particular I have observed, that everything is going correct untill the w.show(). then, suddenly happens moveEvent(), which changes the self.pos(). In my case it happened because at construction of the combined window, its size was changed and it was moved in origin... Reservation of larger window size solved this problem.

Close window and delete object

    def closeEvent(self, event):
        try: # try to delete self object in the cp.confpars
            del cp.confpars.guiconfigparameters 
        except # AttributeError:
            pass # silently ignore

Change style of buttons depending on status

For particular QPushButton it works:

self.but_path = QtGui.QPushButton('File:')
self.but_path.setObjectName('but_path')
self.but_path.setStyleSheet('QPushButton#but_path:pressed  {color: black; background-color: green;}' +
                            'QPushButton#but_path:disabled {color: white; background-color: pink;}' +
                            'QPushButton                   {color:  blue; background-color: yellow;}')

For entire application it should be like:

app = QtGui.QApplication.instance()
app.setStyleSheet('QLabel{color: #fff;} QPushButton{background-color: #000; color: #fff}')

but does not work for me...

Matplotlib

In examples below we assume

fig = plt.figure(num=1, figsize=(10,10), dpi=100, facecolor='w',edgecolor='w',frameon=True)
axes = fig.add_subplot(111)
axim = axes.imshow(arrwin, interpolation='nearest', origin='bottom', aspect='auto', extent=[xmin, xmax, ymax, ymin])

Clear figure

fig.clear()

Graphic

axes.plot(xarr1, yarr1, '-r', xarr2, yarr2,  '-g')

Histogram

axes.hist(arr, bins=100, range=(10,50), log=False) # log for vertical scale only

Image (with colorbar)

img = axes.imshow(arr2d, interpolation='nearest', origin='bottom', aspect='auto')
img.set_clim(Amin,Amax)

cbar = self.fig.colorbar(img, orientation='vertical', \
                         fraction=0.1, pad=0.01, shrink=1.0, aspect=20)

        # fraction - of the 2d plot occupied by the color bar
        # pad      - is a space between 2d image and color bar
        # shrink   - factor for the length of the color bar
        # aspect   - ratio length/width of the color bar

Color bar as a separate sub-plot

axcb = fig.add_axes([0.1,  0.1, 0.8, 0.1])
cbar = fig.colorbar(img, cax=axcb, orientation='horizontal', \
                    fraction=0.1, pad=0.01, shrink=1.0, aspect=20)
axcb.xaxis.set_ticks_position('top') # change position of axis labels

Define subplot(s) with empty axes

axes  = fig.add_subplot(111)

or

axes1  = fig.add_subplot(211)        
axes2  = fig.add_subplot(212)

Make figure with non-equal subplots

axgr = fig.add_axes([0.1,  0.64, 0.80, 0.35])
axhi = fig.add_axes([0.1,  0.14, 0.35, 0.35])
axti = fig.add_axes([0.55, 0.14, 0.35, 0.35])

or using grid:

import matplotlib.gridspec as gridspec
gs   = gridspec.GridSpec(20, 20)
# Naive direction        [  Y   ,   X ]
axsa = fig.add_subplot(gs[ 1:16,  0:14])
axsb = fig.add_subplot(gs[ 1:16, 14:19])
axsc = fig.add_subplot(gs[16:  ,  0:14])

Set axes limits

    
axes.set_xlim((-50,50))
axes.set_ylim((-10,210))

Draw line

import matplotlib.lines  as lines
line = lines.Line2D(arrx, arry, linewidth=1, color='r')   
axes.add_artist(line)

Set a number of ticks along the axis

from matplotlib.ticker import MaxNLocator
axes.xaxis.set_major_locator(MaxNLocator(4))

Axis without tick-labels

import matplotlib.ticker as mtick
axes.xaxis.set_major_formatter( mtick.NullFormatter() )

Rotate axis tick-labels

for label in axes.get_xticklabels() :
    label.set_rotation(60)                  # rotate by 60 degree
    label.set_horizontalalignment('center') # 'right', etc.

Change axis tick-label position on the plot

axes.xaxis.set_ticks_position('top')
axes.yaxis.set_ticks_position('right')

Axes labels

axes.set_xlabel('Time index')
axes.set_ylabel('dt(sec)')

Text in axes

plt.text(x, y, text, fontsize=7, color='k', ha='left', rotation=45)
axes.text(x, y, text, fontsize=7, color='k', ha='left', rotation=45)

Axes title

    
plt.title('Image',color='b',fontsize=20)
or
axes.set_title('Image',color='b',fontsize=20)

Window title

    
    fig.canvas.set_window_title('Image And Spectrum ' + u'\u03C6')

Add unicode symbols in string

    
    str = 'Symbol phi: ' + u'\u03C6'

Get canvas and connect it with mouse buttons

canvas = fig.canvas
canvas.mpl_connect('button_press_event',   self.processMouseButtonPress) 
canvas.mpl_connect('button_release_event', self.processMouseButtonRelease) 
canvas.mpl_connect('motion_notify_event',  self.processMouseMotion)

...

    def processMouseButtonPress(self, event) :
        print 'MouseButtonPress'
        print 'event: xdata, ydata, x, y =', event.xdata, event.ydata, event.x, event.y

        if event.inaxes == self.axgr : self.mousePressOnGraph(event)
        if event.inaxes == self.axti : self.mousePressOnGraph(event)
        if event.inaxes == self.axhi : self.mousePressOnHisto(event)

        if event.button == 1 : # 1=left, 2=middle, 3=right
            self.gr_xmin = float(event.xdata)

At the edge of matplotlib and PyQt4

We assume that everything is done in our backend basis:

import matplotlib
matplotlib.use('Qt4Agg')
import matplotlib.pyplot as plt

Get the current matplotlib figure window position on monitor

pos = fig.canvas.manager.window.pos()
print 'x,y=', pos.x(), pos.y()

Move the matplotlib figure window in certain (x,y) position

fig.canvas.manager.window.move(x,y) # in pixels from top-left corner

or

plt.get_current_fig_manager().window.move(90, 100)

For our backend starting from python 2.7.2:

plt.get_current_fig_manager().window.geometry("+100+300")

Move the matplotlib figure window on top (of all pileup windows)

fig.canvas.manager.window.activateWindow() # Makes window active
fig.canvas.manager.window.raise_()         # Moves window on top

the attribute trick is that the fig.canvas.manager.window returns the QtGui.QMainWindow, which is subclass of QtGui.QWidget with all that useful methods.

Add figure as a widget of the QtGui

fig = plt.figure(num=None figsize=(5,10), dpi=100, facecolor='w',edgecolor='w',frameon=True)
vbox = QtGui.QVBoxLayout()
vbox.addWidget(fig.canvas)    # Wraps figure canvas in widget 
self.setLayout(vbox)

How to recieve a signal in program when window is activated by the mouse click on frame ?

I do not know yet...

But, if you click on figure canvas (the region inside the window frame, use

        fig.canvas.mpl_connect('button_press_event', self.onButtonPressEvent) 

#Should be implemented something like:
    def onButtonPressEvent( self, event ):
        """Figure is picked"""
        print 'click on fig number =', event.canvas.figure.number

Receive a signal in program when close window by the click on "X"

        fig.canvas.mpl_connect('close_event', self.onCloseEvent)

#Should be implemented something like:
    def onCloseEvent( self, event ):
        print 'close event, fig number =', event.canvas.figure.number

Close figure from program call

plt.close( num ) # close figure with known number num
...
plt.close('all') # close all figures

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