Draw rectangles and lines

[Stefanie Lück]

Hello!

I am new to pyqtgraph and would like to draw a line plot and under the line plot a simple line with a rectangle (see line.jpg). The Lineplot is no problem, everything is working fine but is there any possibility to add a simple line with rectangle under the plot? It can be outside or inside the plot but the line should show up under the line of the plot (see plot.jpg).

Thank you very much in advance!

Stefanie

[Luke Campagnola]

On Wed, Apr 9, 2014 at 9:23 AM, Stefanie Lück <lue...@gmail.com> wrote:

Hello!

I am new to pyqtgraph and would like to draw a line plot and under the line plot a simple line with a rectangle (see line.jpg). The Lineplot is no problem, everything is working fine but is there any possibility to add a simple line with rectangle under the plot? It can be outside or inside the plot but the line should show up under the line of the plot (see plot.jpg).

Certainly; just add a couple of QGraphicsRectItem to your view: http://qt-project.org/doc/qt-4.8/qgraphicsrectitem.html#details

There are a variety of other shapes that Qt provides as well.

If you want the shapes to appear outside the plot (but maintain vertical alignment with the data), then I would something like the following:

# Set up a window with plot

import pyqtgraph as pg

win = pg.GraphicsWindow()

plt = win.addPlot()

plt.plot(x=[0, 0.1, 0.2, 0.3, 0.4], y=[1, 7, 2, 4, 3])

# Add a ViewBox below with two rectangles

vb = win.addViewBox(col=0, row=1)

r1 = pg.QtGui.QGraphicsRectItem(0, 0, 0.4, 1)

r1.setPen(pg.mkPen(None))

r1.setBrush(pg.mkBrush('r'))

vb.addItem(r1)

r2 = pg.QtGui.QGraphicsRectItem(0.2, -5, 0.1, 10)

r2.setPen(pg.mkPen((0, 0, 0, 100)))

r2.setBrush(pg.mkBrush((50, 50, 200)))

vb.addItem(r2)

# Make the ViewBox flat

vb.setMaximumHeight(70)

# Force y-axis to be always auto-scaled

vb.setMouseEnabled(y=False)

vb.enableAutoRange(y=True)

# Force x-axis to match the plot above

vb.setXLink(plt)

[Stefanie Lück]

Thanks for your reply!

Is it also possible to use QGraphicsRectItem  inside a GraphicsLayout? If I do, I I am getting an error. I attached a simplified example.

Thanks

[Stefanie Lück]

The matter has resolved itself!

I found out that I can add a ViewBox to a GraphicsLayout.

self.lay = pg.GraphicsLayout()

vb = self.lay.addViewBox(col=0, row=2)

Best regards