Charting OHLC candle with SMA 200 using mplfinance plot function - charts

Question

I'm using mplfinance plot function to draw OHLC candlestick chart of a symbol. OHLC data is of 2 min timeframe. Also, I'm plotting sma 20 period and sma 200 period on the same chart. Because of sma200, the number of candles which are displayed on chart is quite huge (almost two days of 2min candle)
Since moving average is calculated internally by plot function so I've to pass the two days of 2 min candle to plot function so that I could get some data points of sma200. Candlestick chart is saved as png file. Now because of around 300 candles displayed on chart (sma20 and sma200 line also displayed), candles are not very clearly displayed.
Is there a way to restrict number of candles which get displayed on chart. If I slice my dataframe to lets say 30 candle, then sma200 will not be calculated in that case due to insufficient number of candles. What I need is sma200 with complete dataset but only fixed number of candle or for a fixed duration chart get displayed like last one hour candle data only.
mpf.plot(df, type='candle', style='charles',
title=title,
ylabel='Price',
ylabel_lower='Shares \nTraded',
mav=(20,200),
savefig=file)

Answer 1

I would suggest that you calculate your own moving average, and plot it using mpf.make_addplot(). This will allow you to calculate a moving average based on one-minute or two-minute candles, while plotting five-minute or ten-minute candles. For example:
# calculate mav values
mav20 = twominute_df['Close'].rolling( 20).mean()
mav200 = twominute_df['Close'].rolling(200).mean()
# resample:
resample_ohlcmap = {'Open' :'first',
'High' :'max',
'Low' :'min',
'Close' :'last',
'Volume':'sum'
}
tenminute_df = twominute_df.resample('10T').agg(resample_ohlcmap)
# plot ten-minute candles with two-minute mavs:
apmavs = [ mpf.make_addplot(mav20),
mpf.make_addplot(mav200) ]
mpf.plot(tenminute_df, type='candle', style='charles',
title=title, ylabel='Price', ylabel_lower='Shares \nTraded',
addplot=apmavs, savefig=file)
References:
resampling
moving average calculation

Answer 2

Thanks Daniel for your help. I'm now able to plot a chart for 60 candles with sma 20 and 200.
Well I don't need resampling as my chart timeframe and moving average time frame both are same.
Please find my code snippet.
# get list of close prices from symbol_docs. symbol_docs contain 2 min OHLC.
close_list = list(map(lambda a: a['close'], symbol_docs))
# sma20 and 200 calculated using ta-lib
sma20 = sma(close_list, 20)
sma200 = sma(close_list, 200)
# call to plot_chart function
plot_chart('TCS', symbol_docs, sma20, sma200)
def plot_chart(symbol, docs, sma20, sma200):
df = pd.DataFrame(docs)
df = df.set_index(['time'])
df.rename(columns={'open': 'Open', 'close': 'Close', 'high': 'High', 'low': 'Low'},
inplace=True)
title = symbol.upper() + ' - 2min'
file = saved_chart_image_abs_path + symbol + '.png'
df['sma20'] = sma20
df['sma200'] = sma200
df_sliced = df[-60:]
apmavs = [mpf.make_addplot(df_sliced['sma20']), mpf.make_addplot(df_sliced['sma200'])]
mpf.plot(df_sliced, type='candle', style='charles',
title=title,
ylabel='Price',
ylabel_lower='Shares \nTraded',
addplot=apmavs,
savefig=file)
telegram_message_sender.send_document(file)
os.remove(file)
Below chart is sent as a document on my telegram group :)