Plotting a candlestick chart in the backtest - Question

To plot a candlestick chart on the minute resolution in a backtest for the stocks you trade, you can follow these steps using QuantConnect's API:

1. Initialize the Algorithm: Set the start and end dates, initial cash, and add the equity with minute resolution.

2. Create a Chart: In the initialize method, create a Chart object to hold the candlestick series.

3. Add Candlestick Series: Use CandlestickSeries to add a candlestick series to the chart for the stock you are trading.

4. Add the Chart to the Algorithm: Use self.add_chart(chart) to add the chart to your algorithm.

5. Consolidate Data: Use the self.consolidate method to consolidate minute data into the desired time frame for plotting.

6. Plot Data: In the on_data method, use self.plot to plot the candlestick data on the chart.

7. Run the Backtest: Execute the backtest to visualize the candlestick chart in the results.

Here's a sample implementation:

from datetime import timedelta
from QuantConnect.Data.market import TradeBar
class CandlestickChartAlgorithm(QCAlgorithm):
    def initialize(self):
        self.set_start_date(2022, 1, 1)
        self.set_end_date(2022, 12, 31)
        self.set_cash(100000)
        # Add equity with minute resolution
        self.symbol = self.add_equity("SPY", Resolution.MINUTE).symbol
        # Create a candlestick chart
        candlestick_chart = Chart("Candlestick Chart")
        candlestick_series = CandlestickSeries("SPY")
        candlestick_chart.add_series(candlestick_series)
        self.add_chart(candlestick_chart)
        # Consolidate minute data to plot
        self.consolidate(self.symbol, timedelta(minutes=1), self.on_consolidated)
    def on_consolidated(self, bar: TradeBar):
        # Plot the candlestick data
        self.plot("Candlestick Chart", "SPY", bar)
    def on_data(self, data: Slice):
        # Implement your trading logic here
        pass

This code sets up a candlestick chart for the SPY stock using minute resolution data. The on_consolidated method is used to plot the candlestick data on the chart. You can adjust the symbol and time frame as needed for your specific use case.

Sources: Custom Charting Algorithm, Charting - QuantConnect.com, Alternative Data - QuantConnect.com, Forex - QuantConnect.com, CFD - QuantConnect.com

Do we need on_consolidated method even if we already using minute resolution?

Hi RIF87

Indeed you don't need to! Just using the trade bar received is fine.

def on_data(self, data: Slice):
    if self.symbol in slice.bars:
        self.plot("Candlestick Chart", "SPY", slice.bars[self.symbol])

Best
Louis