title: How to draw Pivot points using plotly?
body: <p>I'm using plotly to draw some chart with SMA and MACD data. This works fine.</p>
  <pre><code>fig = make_subplots(vertical_spacing = 0, rows=3, cols=1, row_heights=[0.6, 0.2, 0.2])
  
  fig.add_trace(go.Ohlc(x=data['timestamp'],
              open=data['open'],
              high=data['high'],
              low=data['low'],
              close=data['close']))
  
  fig.add_trace(go.Scatter(x=data['timestamp'], y=data['sma'], line=dict(color='orange', width=1)), row=1, col=1)
  
  
  fig.add_trace(go.Scatter(x=data['timestamp'], y = data['macd']), row=2, col=1)
  fig.add_trace(go.Scatter(x=data['timestamp'], y = data['macds']*1.1), row=2, col=1)
  fig.add_trace(go.Bar(x=data['timestamp'], y = data['volume']), row=3, col=1)
  fig.update_layout(xaxis_rangeslider_visible=False,
                  xaxis=dict(zerolinecolor='black', showticklabels=False),
                  xaxis2=dict(showticklabels=False))
  
  fig.update_xaxes(showline=True, linewidth=1, linecolor='black', mirror=False)
  fig.show()
  </code></pre>
  <p>But now I want to add pivots:</p>
  <pre><code>    last_day['Pivot'] = (last_day['High'] + last_day['Low'] + last_day['Close'])/3
      last_day['R1'] = 2*last_day['Pivot'] - last_day['Low']
      last_day['S1'] = 2*last_day['Pivot'] - last_day['High']
      last_day['R2'] = last_day['Pivot'] + (last_day['High'] - last_day['Low'])
      last_day['S2'] = last_day['Pivot'] - (last_day['High'] - last_day['Low'])
      last_day['R3'] = last_day['Pivot'] + 2*(last_day['High'] - last_day['Low'])
      last_day['S3'] = last_day['Pivot'] - 2*(last_day['High'] - last_day['Low'])
  </code></pre>
  <p>The output of last_day looks like this:</p>
  <pre><code>                    Timestamp      Open      High       Low     Close  Volume    Pivot        R1        S1        R2        S2        R3        S3
  499  2020-10-11T14:45:00.000Z  0.000321  0.000321  0.000319  0.000319  886.17  0.00032  0.000321  0.000319  0.000322  0.000318  0.000323  0.000316
  </code></pre>
  <p>How can I add this data (Pivot, S1, S2, S3, ...) to my figure? I would want to have something comparable with the picture here: <a href="https://www.fxpivot-points.com/?page=4" rel="nofollow noreferrer">https://www.fxpivot-points.com/?page=4</a></p>
  <p><a href="https://i.stack.imgur.com/O4YTa.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/O4YTa.png" alt="enter image description here" /></a></p>
  <p>I tried this:</p>
  <pre><code>fig.add_trace(go.Scatter(x=last_day['Timestamp'], y=last_day['Pivot'], line=dict(color='purple', width=1)), row=1, col=1)
  </code></pre>
  <p>But it only draws a dot since I provide only one timestamp. How can I make this a horizontal line?</p>