It works, thank you so much!
понедельник, 29 апреля 2019 г., 7:55:49 UTC+3 пользователь Patrick написал:
>
> Hi,
>
> I don't know exactly why that would be happening, but seems like a
> rounding error somewhere. Your bounding box function is returning a y-axis
> range of 0 to 1 (which I assume is from the minimum size of the picture
> object maybe?) even though the data is a million times smaller than that.
>
> If I change the bounding box method to:
> # import numpy as np
> def boundingRect(self):
> data = np.array(self.data)
> xmin = data[:,0].min()
> xmax = data[:,0].max()
> ymin = data[:,1:].min()
> ymax = data[:,1:].max()
> return QtCore.QRectF(xmin, ymin, xmax-xmin, ymax-ymin)
> then it seems to work better.
>
> Also needed to change this for python3:
> request_data = json.loads(data.decode('utf8'))
>
> Patrick
>
> On Monday, 29 April 2019 04:23:40 UTC+9:30, [email protected] wrote:
>>
>> I use pyqtgraph to draw the candles, but if I zoom graph very much, image
>> hide.
>>
>> I noticed that when zoom very much, “paint” method stops being called.
>> Code with http request to exchange below.
>>
>> import pyqtgraph as pgfrom pyqtgraph import QtCore, QtGuifrom PyQt5 import
>> QtWidgets
>> class CandlestickItem(QtWidgets.QGraphicsRectItem):
>> def __init__(self, data):
>> super(CandlestickItem, self).__init__()
>> self.data = data
>> self.generatePicture()
>>
>> def generatePicture(self):
>> self.picture = QtGui.QPicture()
>> p = QtGui.QPainter(self.picture)
>> p.setPen(pg.mkPen('w'))
>> w = (self.data[1][0] - self.data[0][0]) / 3.
>> for (t, open, close, min, max) in self.data:
>> if max != min:
>> p.drawLine(QtCore.QPointF(t, min), QtCore.QPointF(t, max))
>> if open > close:
>> p.setBrush(pg.mkBrush('r'))
>> else:
>> p.setBrush(pg.mkBrush('g'))
>> p.drawRect(QtCore.QRectF(t - w, open, w * 2, close - open))
>> p.end()
>>
>> def paint(self, p, *args):
>> print('paint call')
>> p.drawPicture(0, 0, self.picture)
>>
>> def boundingRect(self):
>> return QtCore.QRectF(self.picture.boundingRect())
>>
>> if __name__ == '__main__':
>> import sys
>> import urllib.request
>> import json
>>
>> get_symbols_url =
>> 'https://api.hitbtc.com/api/2/public/candles/BCNBTC?period=M30&limit=1000'
>> response = urllib.request.urlopen(get_symbols_url)
>> request_data = json.loads(response.read())
>> data_list = []
>> for i in range(0, len(request_data)):
>> data_list.append((float(i), float(request_data[i]['open']),
>> float(request_data[i]['close']),
>> float(request_data[i]['min']),
>> float(request_data[i]['max'])))
>>
>> item = CandlestickItem(data_list)
>> plt = pg.plot()
>> plt.addItem(item)
>>
>> if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
>> QtGui.QApplication.instance().exec_()
>>
>> I need to display very small values, for example, 0.0000001-0.00000015.
>> What can I do to prevent image hidden at high zoom?
>>
>>
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