Content
Python tricks
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...
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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)
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Dictionaris, Lists, etc
Make dictionary from two lists
k = ['a', 'b', 'c'] v = [1, 2, 3] d = dict(zip(keys, values)) >>> print dictionary {'a': 1, 'b': 2, 'c': 3} |
Sorted list
Get sorted list from non-sorted:
Define non-default order of elements:
def __cmp__(self, other) :
"""Method for sorted()"""
if self.begin < other.begin : return -1
if self.begin > other.begin : return 1
if self.begin == other.begin :
if self.end < other.end : return 1 # inverse comparison for end
if self.end > other.end : return -1
if self.end == other.end : return 0 |
Exceptions
Standard exceptions
Raise exceprion
if not os.path.lexists(fname) : raise IOError('File %s is not available' % fname) |
Catch exception
try :
plf = PeakListFile(fname)
except Exception as e:
print 'We cought exception: %s' % e |
User defined exception
class MyError(Exception):
def __init__(self, value):
self.value = value
def __str__(self):
return repr(self.value)
...
try:
raise MyError(2*2)
except MyError as e:
print 'My exception occurred, value:', e.value |
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'
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Parsing the pathname
path = '/reg/d/psdm/cxi/cxif5315/calib/pnccd/pnccd-123456.data'
root, ext = os.path.splitext(path) # ('/reg/d/psdm/cxi/cxif5315/calib/pnccd/pnccd-123456', '.data') # or '' if something is missing
basename = os.path.basename(path) # pnccd-123456.data
dirname = os.path.dirname(path) # /reg/d/psdm/cxi/cxif5315/calib/pnccd
lexist = os.path.lexists(path) # False
isfile = os.path.isfile(path) # False
isdir = os.path.isdir(path) # False
head, tail= os.path.split(path) # ('/reg/d/psdm/cxi/cxif5315/calib/pnccd', 'pnccd-123456.data') # or '' if something is missing
...
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http://docs.python.org/library/os.path.html
Join list of strings
Join path and name
path_name = os.path.join(path,fname)
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Check if string contains pattern
exp = 'xpptut13'
if 'tut' is in exp : <do something> |
String alignment
msg = '%s' % (k.ljust(16)) |
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)
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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')
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Replace the part of the string
my_string.replace("abcde","cde")
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String formatting
s = 'some text %s %s' % (msg.ljust(30), str(val).rjust(30)
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Class string properties
print 'string properties:'
print 'punctuation : ', string.punctuation
print 'digits : ', string.digits
print 'octdigits : ', string.octdigits
print 'hexdigits : ', string.hexdigits
print 'ascii_letters : ', string.ascii_letters
print 'ascii_lowercase: ', string.ascii_lowercase
print 'ascii_uppercase: ', string.ascii_uppercase
print 'lowercase : ', string.lowercase
print 'uppercase : ', string.uppercase
print 'letters : ', string.letters
print 'printable : ', string.printable
print 'whitespace : ', string.whitespace |
Class name
Function name
sys._getframe().f_code.co_name |
Function parameters
locals() # returns (dict) of method input parameters |
Converting integer to bin(), oct(), hex() string
using built-in functions
ival = 123456
str_bin = bin(ival)
str_oct = oct(ival)
str_hex = hex(ival) |
Time stamp
from time import localtime, gmtime, strftime, clock, time
time_sec = time() # epoch time
def get_current_local_time_stamp(fmt='%Y-%m-%d %H:%M:%S %Z'):
return strftime(fmt, localtime())
def get_current_gm_time_stamp(fmt='%Y-%m-%d %H:%M:%S %Z'):
return strftime(fmt, gmtime())
def get_local_time_str(time_sec, fmt='%Y-%m-%d %H:%M:%S %Z'):
return strftime(fmt, localtime(time_sec))
def get_gm_time_str(time_sec, fmt='%Y-%m-%d %H:%M:%S %Z'):
return strftime(fmt, gmtime(time_sec)) |
Set PYTHONPATH
In command-line:
setenv PYTHONPATH /reg/neh/home1/dubrovin/LCLS/git-work/pyapps:${PYTHONPATH} |
In cshell script:
alias setpp 'setenv PYTHONPATH /reg/neh/home1/dubrovin/LCLS/git-work/pyapps:${PYTHONPATH}' |
In code:
import os
os.environ['PYTHONPATH'] = '/reg/neh/home1/dubrovin/LCLS/git-work/pyapps:%s' % os.environ.get('PYTHONPATH', '') |
Replace symbols in string
text.replace("|",":").replace("-",".")
range.replace('9999','end')
msg.replace('\n',' ') |
List of comprehension
list_of_x2 = [x*x for x in list_of_x]
list_of_x_selected = [x for x,y in zip(list_of_x, list_of_y) if y>0]
map - built-in method
def f(x,y) :
return x if y>0 else -x
list = map(f, arrX, arrY) |
Constructor, destructor etc.
class PeakListFile :
def __init__(self, fname) :
print 'constructor'
self.f=open(fname,'r')
def __del__(self) :
print 'destructor'
try :
self.f.close()
def __call__(self) :
print 'this is a default method of this object called as obj()' |
Polymorphism
Derived class initialization
class Base :
def __init__(self) :
...
class Derived(Base) :
def __init__(self) :
Base.__init__(self)
# OR
super(Derived, self).__init__() |
Create/save temporary file
import tempfile
tmp_file = tempfile.NamedTemporaryFile(mode='r+b',suffix='.tiff')
tfile = tmp_file.name |
Good example of __main__
import sys
def test_all() :
print _sep_, '\n%s' % sys._getframe().f_code.co_name
test_ricker()
test_morlet()
#------------------------------
if __name__ == "__main__" :
from time import time
tname = sys.argv[1] if len(sys.argv) > 1 else '0'
print 50*'_', '\nTest %s:' % tname
t0_sec = time()
if tname == '0': test_all()
elif tname == '1': test_ricker()
elif tname == '2': test_morlet()
else : print 'Not-recognized test name: %s' % tname
msg = 'End of test %s, consumed time (sec) = %.6f' % (tname, time()-t0_sec)
sys.exit(msg) |
Virtualenv
virtualenv dir-name
source <directoryName>/bin/activate.csh # for tcsh
# or
source <directoryName>/bin/activate # for bash
pip install <packageName>
... work
deactivate |
Python - useful references
Built-in functions
http://docs.python.org/library/functions.html
setattr, getattr - set/get dynamic variables in python
http://docs.python.org/library/functions.html#setattr
PyQt4
Know How
- QGraphicsScene item priority is set by setZValue(v)
- All re-implemented Event methods like {{mouseMoveEvent(self, e)}} etc. in items will get control only if QGraphicsView their default version will be called.
PyQt4 class references
All classes
Selected:
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()
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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
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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;}')
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For entire application it should be like:
app = QtGui.QApplication.instance()
app.setStyleSheet('QLabel{color: #fff;} QPushButton{background-color: #000; color: #fff}')
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but does not work for me...
Make window visible on the top
Scroll down text in
Assuming
self.box_txt = QtGui.QTextEdit()
self.box_txt.setText('some text')
self.box_txt.append('a lot of additional text, exceeding the window size')
self.box_txt.ensureCursorVisible()
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Scroll bar can be used, but result is not seen imidiately:
scrol_bar_v = self.box_txt.verticalScrollBar() # QScrollBar
scrol_bar_v.setValue(scrol_bar_v.maximum())
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Moving text cursor with repaint() works immidiately:
self.box_txt.moveCursor(QtGui.QTextCursor.End)
self.box_txt.repaint()
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Set optimal table-widget size
self.table = QtGui.QTableWidget(rows, cols, self)
...
self.table.setFixedWidth(self.table.horizontalHeader().length() + 4)
self.table.setFixedHeight(self.table.verticalHeader().length() + 29)
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Show image in QLabel
Assumes:
class GUIImage ( QtGui.QLabel ) :
def __init__ (self, parent=None, app=None) :
QtGui.QLabel.__init__(self, parent)
self.setGeometry(200, 100, 100, 100)
self.setWindowTitle('Image For Grabber')
self.setFrame()
...
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i.e. self
is an instance of QLabel
.
Set pixmap for image
def setPixmapForImage(self):
if self.r_pixmap == None :
self.s_pixmap = None
self.clear()
else :
self.s_pixmap = self.r_pixmap.scaled(self.size(), QtCore.Qt.KeepAspectRatio)
self.setPixmap(self.s_pixmap)
self.setAlignment(QtCore.Qt.AlignTop | QtCore.Qt.AlignLeft)
self.setScailedMask()
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Grab image from monitor
import tempfile
def grabImage(self):
fname = tempfile.NamedTemporaryFile(mode='r+b',suffix='.ppm')
if( 0 == os.system('import -trim -frame -border %s' % (fname.name))) :
self.r_pixmap = QtGui.QPixmap(QtGui.QImage(fname.name,'.ppm'))
self.setPixmapForImage()
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Supported in QImage formats:
Format | Description | Qt's support |
---|
BMP | Windows Bitmap | Read/write |
GIF | Graphic Interchange Format (optional) | Read |
JPG | Joint Photographic Experts Group | Read/write |
JPEG | Joint Photographic Experts Group | Read/write |
PNG | Portable Network Graphics | Read/write |
PBM | Portable Bitmap | Read |
PGM | Portable Graymap | Read |
PPM | Portable Pixmap | Read/write |
TIFF | Tagged Image File Format | Read/write |
XBM | X11 Bitmap | Read/write |
XPM | X11 Pixmap | Read/write |
Grab entire monitor window
def grabEntireWindow(self):
self.r_pixmap = QtGui.QPixmap.grabWindow(QtGui.QApplication.desktop().winId())
self.setPixmapForImage()
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Load image from file
def loadImageFromFile(self, fname) :
#Read formats: bmp, jpg, jpeg, png, ppm, xbm, xpm + gif, pbm, pgm,
self.r_pixmap = QtGui.QPixmap(QtGui.QImage(fname))
self.setPixmapForImage()
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Set the mask to suppress the background layer
def setScailedMask(self):
size = self.s_pixmap.size()
print 'Scaled pixmap size: %d x %d' % (size.width(), size.height())
#==================================
self.qimage_mask = QtGui.QImage(size, QtGui.QImage.Format_Mono)
self.qimage_mask.fill(0)
self.qbitmap_mask = QtGui.QBitmap.fromImage(self.qimage_mask)
self.s_pixmap.setMask(self.qbitmap_mask)
#==================================
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Save image in file
def saveImageInFile(self, fname='test.png'):
#Write formats: bmp, jpg, jpeg, png, pbm, pgm, ppm, xbm, xpm
if self.r_pixmap is not None :
self.r_pixmap.save(fname, format=None)
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Set transparent frame
def setFrame(self):
self.frame = QtGui.QFrame(self)
self.frame.setFrameStyle( QtGui.QFrame.Box | QtGui.QFrame.Sunken ) #Box, Panel | Sunken, Raised
self.frame.setLineWidth(0)
self.frame.setMidLineWidth(1)
self.frame.setGeometry(self.rect())
#self.frame.setVisible(False)
self.frame.setStyleSheet('background: transparent;')
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Resize event
def resizeEvent(self, e):
s = self.size()
self.frame.setGeometry(QtCore.QRect(0,0,s.width(),s.height()))
self.setPixmapForImage()
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Get window size and position
Global (top-left) point of the window on monitor:
point = self.mapToGlobal(QtCore.QPoint(0,0))
- changing in resizeEvent(...)
and moveEvent(...)
x,y,w,h = size.size().x(), size.size().y(), size.size().width(), size.size().height()
where - w and h changing in resizeEvent(...)
,
x,y changing in moveEvent(...)
only.
Window relative dims: rect = self.rect()
- changing in resizeEvent(...)
Show image in QtGui.QGraphicsView
QGraphicsView is a class with scrolled graph window...
Repaint widget immediately when its property is changed
When QPushButton is pressed and connected method is called, all button properties stay unchanged until the method. In order to see current changes one has to repaint widget. For example:
self.but_elog.setStyleSheet(cp.styleButton)
self.but_elog.setEnabled(False)
self.repaint() |
Dialog boxes
For password
app = QtGui.QApplication(sys.argv)
w = QtGui.QInputDialog()
w.show()
msg = 'To use %s and submitt messages in ELog\nauthentication for user %s is required\nPassword:' % (sys.argv[0], opts.usr)
text, ok = w.getText(None, 'Authentication', msg, QtGui.QLineEdit.Password)
w.close()
... |
Graphics in PyQt4
...
self.poi1 = QtCore.QPoint(0,0)
self.poi2 = QtCore.QPoint(0,0)
self.rect1 = QtCore.QRect()
self.rect2 = QtCore.QRect()
self.pen1 = QtGui.QPen(QtCore.Qt.black)
self.pen2 = QtGui.QPen(QtCore.Qt.white)
self.pen1.setStyle(QtCore.Qt.DashLine)
self.pen2.setStyle(QtCore.Qt.DashLine)
self.pen1.setWidthF(1)
self.pen2.setWidthF(1)
...
def paintEvent(self, e):
super(GUIImage,self).paintEvent(e)
qp = QtGui.QPainter()
# or QPainter can be defined earlier and use it as qp = self.qp
qp.begin(self)
#self.drawPixmap(qp)
self.drawRect(qp)
qp.end()
self.update()
def setPen(self, qp):
self.pen.setStyle(QtCore.Qt.DashLine)
self.pen.setWidthF(1)
def drawRect(self, qp):
if self.r_pixmap == None:
return
p1x, p1y = self.poi1.x(), self.poi1.y()
p2x, p2y = self.poi2.x(), self.poi2.y()
R=1
if abs(p2x-p1x) < R : return
if abs(p2y-p1y) < R : return
self.rect1.setCoords( p1x, p1y, p2x, p2y)
self.rect2.setCoords( p1x+1, p1y+1, p2x-1, p2y-1)
qp.setPen (self.pen1)
qp.drawRect(self.rect1);
qp.setPen (self.pen2)
qp.drawRect(self.rect2);
def drawPixmap(self, qp):
if self.r_pixmap != None:
qp.drawPixmap(0,0,self.s_pixmap)
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See other draw options in QPainter class reference.
Style options
self.styleTransp = "background-color: rgb(255, 0, 0, 100);"
self.styleTitle = "background-color: rgb(239, 235, 231, 255); color: rgb(100, 160, 100);" # Gray bkgd
self.styleWhite = "background-color: rgb(255, 255, 255); color: rgb(0, 0, 0);"
self.styleTitleBold = self.styleTitle + 'font-size: 18pt; font-family: Courier; font-weight: bold;'
self.styleWhiteFixed= self.styleWhite + 'font-family: Fixed;'
self.colorEditInfo = QtGui.QColor(100, 255, 200)
self.colorEditBad = QtGui.QColor(255, 0, 0)
self.colorEdit = QtGui.QColor('white')
self.but_close .setStyleSheet (cp.styleButton)
self.but_close .setFlat(True)
self.but_logger.setVisible(True)
self.box_txt .setReadOnly(True)
self.tit_title .setAlignment(QtCore.Qt.AlignTop | QtCore.Qt.AlignCenter)
self.but_logger.setIcon(cp.icon_contents)
self.setMinimumWidth(400)
self.setMinimumHeight(320)
self.setMinimumSize(600,700)
self.setFixedHeight(350)
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Icons
path = './icons/'
self.icon_contents = QtGui.QIcon(path + 'contents.png')
self.but_logger.setIcon(cp.icon_contents)
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Tooltips
self.edi_usr.setToolTip('Sender of the message')
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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])
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Save figure in file
fig.savefig(fname, dpi=240)
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Clear figure
Graphic
import pyimgalgos.Graphics as gr
axes.clear()
axes.plot(xarr1, yarr1, '-r', xarr2, yarr2, '-g')
gr.show(mode='do_not_hold') |
Histogram
axes.clear()
axes.hist(arr, bins=100, range=(10,50), log=False) # log for vertical scale only
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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
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Color bar as a separate sub-plot
axcb = fig.add_axes([0.1, 0.1, 0.8, 0.1]) # x0, y0, width, height
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
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Define subplot(s) with empty axes
axes = fig.add_subplot(111)
|
or
axes1 = fig.add_subplot(211)
axes2 = fig.add_subplot(212)
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Make figure with non-equal subplots
# x0, y0, width, height
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])
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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])
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Set axes limits
axes.set_xlim((-50,50))
axes.set_ylim((-10,210))
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Draw line
import matplotlib.lines as lines
line = lines.Line2D(arrx, arry, linewidth=1, color='r')
axes.add_artist(line)
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Set a number of ticks along the axis
from matplotlib.ticker import MaxNLocator
axes.xaxis.set_major_locator(MaxNLocator(4))
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Axis without tick-labels
import matplotlib.ticker as mtick
axes.xaxis.set_major_formatter( mtick.NullFormatter() )
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Rotate axis tick-labels
for label in axes.get_xticklabels() :
label.set_rotation(60) # rotate by 60 degree
label.set_horizontalalignment('center') # 'right', etc.
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Change axis tick-label position on the plot
axes.xaxis.set_ticks_position('top')
axes.yaxis.set_ticks_position('right')
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Change axis tick-label font size
axes.tick_params(axis='both', which='major', labelsize=8)
|
Axes labels and size
axes.set_xlabel('Time index', fontsize=10)
axes.set_ylabel('dt(sec)', fontsize=8)
|
Axes labels with LaTeX symbols
Use raw
string with LaTeX notations inside:
axes.set_xlabel(r'$\rho A_i$')
|
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)
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Window title for figure
fig = plt.figure(figsize=(15,5), dpi=80, facecolor='w',edgecolor='w',frameon=True)
fig.canvas.set_window_title('Image And Spectrum ' + u'\u03C6')
|
Axes title
plt.title('Image',color='b',fontsize=20)
or
axes.set_title('Image',color='b',fontsize=20)
|
Log scale methods
Log values:
from math import log10
log_vmin, log_vmax = log10(vmin), log10(vmax)
|
Log scale axes:
axes.set_xscale('log')
axes.set_yscale('log')
|
Log scale image data:
self.arr2d = np.log10(self.arrwin)
self.imsh = axis.imshow(self.arr2d, origin='upper', \
interpolation='nearest', \
extent=self.range, aspect='auto')
self.imsh.set_clim(log_vmin,log_vmax)
|
Histogram with log statistics (y axis):
axes.hist(self.arrwin.flatten(), bins=self.nbins, range=self.range_his, log=True)
|
Plot histogram with log bin size:
logbins=10**np.linspace(log_vmin, log_vmax, nbins)
# or:
logbins=np.logspace(log_vmin, log_vmax, nbins)
self.axhi.hist(self.arrwin.flatten(), bins=logbins )
|
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)
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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
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Check and set backend
import matplotlib
if matplotlib.get_backend() != 'Qt4Agg' :
matplotlib.use('Qt4Agg')
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Get the current matplotlib figure window position on monitor
pos = fig.canvas.manager.window.pos()
print 'x,y=', pos.x(), pos.y()
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Move the matplotlib figure window in certain (x,y) position
fig.canvas.manager.window.move(x,y) # in pixels from top-left corner
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or
plt.get_current_fig_manager().window.move(90, 100)
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For our backend starting from python 2.7.2:
plt.get_current_fig_manager().window.geometry("+100+300")
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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
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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)
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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
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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
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Close figure from program call
plt.close( num ) # close figure with known number num
...
plt.close('all') # close all figures
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Emit your own signal in PyQt4
from PyQt4 import QtGui, QtCore
class Drag ( QtCore.QObject ):
def __init__(self) :
QtCore.QObject.__init__(self, None) # need it for signal exchange...
...
self.emit( QtCore.SIGNAL('new_xy_center(int,int)'), x, y)
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Receive your own signal in PyQt4
from PyQt4 import QtGui, QtCore
class BatchJobCorAna( QtCore.QObject ) :
def __init__(self) :
QtCore.QObject.__init__(self, None) # need it for signal exchange...
...
def connectToThread1(self):
#try : self.connect( thread1, QtCore.SIGNAL('update(QString)'), self.updateStatus )
try : self.connect( thread1, QtCore.SIGNAL('new_xy_center(int,int)'), self.updateStatus )
except : logger.warning('connectToThread1 IS FAILED !!!', __name__)
def updateStatus(self, x, y):
print 'BatchJobCorAna: Signal is recieved, x,y=', x, y
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where thread1
is an object emiting the signal.
NumPy
Import
#!/usr/bin/env python
import numpy as np
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Load numpy array from text file
nparr = np.loadtxt('arr.txt', dtype=np.float)
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Load numpy array from *.npy file
nparr = np.load('arr.npy')
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errors = 0.5*np.random.normal(size=len(yn))
Save numpy arrays
np.savetxt(fname, array) # , fmt='%f')
np.save(fname, array)
np.savez(fname, [array1, array2,...])
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Save image in 8-bit TIFF file
import scipy.misc as scim
scim.imsave('fname.tiff', arr2d)
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Other supported formats: gif, pdf, png, jpeg, eps
Check tiff file
To check tiff file format one may use command:
% identify -verbose <file-name>.tiff
Save image in 16-bit TIFF file
import Image
img = Image.fromarray(arr.astype(np.int16)) # or int32
img.save('fname.tiff') |
Read image from TIFF file
import scipy.misc as scim
arr2d = scim.imread('fname.tiff')
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2-d Array rotation by n*90 degree
#!/usr/bin/env python
import numpy as np
a = np.arange(12.).reshape((4, 3))
print 'Input array a=\n',a
print 'rotation for 90 flipud(a.T)=\n',np.flipud(a.T)
print 'rotation for 180 flipud(np.fliplr(a))=\n',np.flipud(np.fliplr(a))
print 'rotation for 270 fliplr(a.T)=\n',np.fliplr(a.T) |
Fill histograms using np.bincount
binstat = np.bincount(self.rbinind.flatten(), weights=self.mask.flatten(), minlength=self.rrange[2])
bin_integral = np.bincount(self.rbinind.flatten(), weights=image.flatten(), minlength=self.rrange[2]) |
Use np.select
V = np.array(...)
Vmin, Vmax, Nbins1 <--- scalar valuer
indarr = np.int32( factor * (V-Vmin) )
arr = np.select([V==Vmax, indarr<0, indarr>Nbins1], [Nbins1, 0, 0], default=indarr) |
protected division:
def divideZeroProteced(nda_num, nda_den, val_subst_zero=0) :
pro_num = np.select([nda_den==0], [val_subst_zero], default=nda_num)
pro_den = np.select([nda_den==0], [1], default=nda_den)
return pro_num / pro_den |
SciPy
Import
#!/usr/bin/env python
import numpy as np
from scipy.optimize import curve_fit
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Fit to data
Reference to scipy.optimize.curve_fit
Fitting data example
Working example:
#!/usr/bin/env python
import numpy as np
from scipy.optimize import curve_fit
def func(x, a, b, c):
return a*np.exp(-b*x) + c
p0 = [2.5, 1.3, 0.5]
x = np.linspace(0, 5, 50)
y = func(x, *p0)
yn = y + 0.2*np.random.normal(size=len(x))
en = 1.1*np.random.normal(size=len(x))
popt, pcov = curve_fit(func, x, yn, p0, en)
yf = func(x, *popt)
print "p0 = ", p0
print "popt = ", popt
print "pcov:\n", pcov
# Let's plot it now
import matplotlib.pyplot as plt
plt.plot( #x, y, 'r-', \
x, yn, 'g^', \
x, yf, 'bs-')
plt.show()
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