plotting an indicator like super trend

[Mhrashtchi]

Question

Hi,
I want to plot a SuperTrend indicator whose values are stored in the sup_v vector and whose direction values (trend_dir) contain -1 and 1. I want to draw it as one continuous line, not as multiple line segments. The plot should look like a standard SuperTrend, with green color when trend_dir = -1 and red color when trend_dir = 1.
best regards

Code example

[debegr92]

Please add some reference or screenshot how the indicator should look like together with a minimal running example of what you already have.

[Mhrashtchi]

Thanks for your response and attention.
I wrote a simple following code in which I calculated the SMA and split it into two separate vectors: red_points and green_points.
In the attached screenshot, it is clear that in the plotted red_points, the area where the value is NaN is displayed as a horizontal line, while I want that part to remain blank.
I attached datafile so.
Best regards

Code example

import numpy as np
import pandas as pd
from lightweight_charts import Chart


def calculate_sma(df, period: int = 50):
    return pd.DataFrame({
        'time': df['time'],
        f'SMA {period}': df['close'].rolling(window=period).mean()
    }).dropna()



if __name__ == '__main__':
    chart = Chart()
    chart.legend(visible=True)
    df = pd.read_csv('sample.csv')
    chart.set(df)
    sma_data = calculate_sma(df, period=50)
    sma_values = sma_data['SMA 50']
    direction = np.where((sma_values > 34.5) & (sma_values < 36), -1, 1)
    sma_data['SMA_50_RED'] = sma_data['SMA 50'].where(direction == -1, np.nan)
    sma_data['SMA_50_GREEN'] = sma_data['SMA 50'].where(direction == 1, np.nan)
    red_points = sma_data[['time', 'SMA_50_RED']]
    # green_points = sma_data[['time', 'SMA_50_GREEN']]
    line_red = chart.create_line('SMA_50_RED', color='red',width=1)
    line_red.set(red_points)
    # line_green = chart.create_line('SMA_50_GREEN', color='green',width=2)
    # line_green.set(green_points)
    chart.show(block=True)

main4.py

sample.csv

[debegr92]

@Mhrashtchi I do not have a super trend indicator ready to use, so I show you how to plot a simliar indicator using the line color.
In this example, I am plotting the Parabolic Stop And Reverse (PSAR) indicator. Whenever the indicator changes direction, I add a transparent line segment.

The code looks like this:

import os
import sys
import pandas as pd
import numpy as np
from lightweight_charts import Chart
from ta.trend import PSARIndicator

if __name__ == '__main__':
	chart = Chart(inner_width=1, inner_height=1, maximize=True, toolbox=True)
	chart.time_scale(visible=False)
	chart.watermark('Indicator Color Test')
	psarLine = chart.create_line('PSAR', color='rgb(255,255,0)', price_line=False)

	df = pd.read_csv('ohlcv.csv')
	chart.set(df)

	# EMA
	# Parabolic Stop and Reverse
	psarInd = PSARIndicator(df['high'], df['low'], df['close'], fillna=True)
	psarDf = df.copy()
	psarDf['PSAR'] = psarInd.psar()
	# Detect changes and use color
	psarDf["direction"] = (psarDf["PSAR"] > psarDf["close"]).astype(int)
	psarDf["direction_change"] = psarDf["direction"].ne(psarDf["direction"].shift(-1))
	# Assign color
	psarDf["color"] = np.where(
	psarDf["direction_change"],
	"rgba(0,0,0,0)",
		np.where(
			psarDf["direction"] == 1,
			"rgb(255,0,0)",
			"rgb(0,255,0)"
		)
	)

	print(psarDf)
	psarLine.set(psarDf)

	chart.show(block=True)

I always try to have the indicator DataFrame in the exact same length as the OHLC data.

[Mhrashtchi]

Thank you very much for your response and solving my problem