pyqtgraph/doc/source/images/gen_example_imageitem_transform.py
Nils Nemitz 61f067bf7c
Add axis convenience methods and matrix display example (#1726)
* add axis convenient methods and matrix display example

* wrestled wayward space back into docstring

* color map names are case sensitive on Linux

* docstring fix for PlotItem

* protect AxisItem.linkToView from being obscured by DateAxisItem override

* replaced setOrigin method by promoted setPos and setScale

* made tri-state axes switching explicit

* reverted setRect behavior, documentation pass for ImageItem

* minor text adjustment

* implmented some suggested revisions

* fix input parsing for setRect and add tests so that I don't break it again

* don't try to re-add transform after clearing it

* changed example and doc image generators to pg.exec()

* removed commented-out code

* cleaned up transform eqaulity assertion

* restored devoured comment

* restored devoured comment
2021-06-07 07:44:19 -07:00

46 lines
1.4 KiB
Python

"""
generates 'example_false_color_image.png'
"""
import numpy as np
import pyqtgraph as pg
import pyqtgraph.exporters as exp
from pyqtgraph.Qt import QtGui, mkQApp
class MainWindow(pg.GraphicsLayoutWidget):
""" example application main window """
def __init__(self):
super().__init__()
self.resize(420,400)
self.show()
plot = self.addPlot()
# Example: Transformed display of ImageItem
tr = QtGui.QTransform() # prepare ImageItem transformation:
tr.scale(6.0, 3.0) # scale horizontal and vertical axes
tr.translate(-1.5, -1.5) # move 3x3 image to locate center at axis origin
img = pg.ImageItem( image=np.eye(3), levels=(0,1) ) # create example image
img.setTransform(tr) # assign transform
plot.addItem( img ) # add ImageItem to PlotItem
plot.showAxes(True) # frame it with a full set of axes
plot.invertY(True) # vertical axis counts top to bottom
self.timer = pg.QtCore.QTimer( singleShot=True )
self.timer.timeout.connect(self.export)
self.timer.start(100)
def export(self):
print('exporting')
exporter = exp.ImageExporter(self.scene())
exporter.parameters()['width'] = 420
exporter.export('example_imageitem_transform.png')
mkQApp("ImageItem transform example")
main_window = MainWindow()
## Start Qt event loop
if __name__ == '__main__':
pg.exec()