# Hilbert Transform Instantaneous Trendline

get_ht_trendline(quotes)

## Parameters

name | type | notes |
---|---|---|

`quotes` | Iterable[Quote] | Iterable of the Quote class or its sub-class. • See here for usage with pandas.DataFrame |

## Historical quotes requirements

You must have at least `100`

periods of `quotes`

to cover the warmup periods.

`quotes`

is an `Iterable[Quote]`

collection of historical price quotes. It should have a consistent frequency (day, hour, minute, etc). See the Guide for more information.

## Return

```
HTTrendlineResults[HTTrendlineResult]
```

- This method returns a time series of all available indicator values for the
`quotes`

provided. `HTTrendlineResults`

is just a list of`HTTrendlineResult`

.- It always returns the same number of elements as there are in the historical quotes.
- It does not return a single incremental indicator value.
- The first
`6`

periods will have`None`

values for`smooth_price`

since there’s not enough data to calculate. - The first
`7`

periods will have`None`

values for`dc_periods`

since there is not enough data to calculate; and are generally unreliable for the first ~25 periods.

⚞

Convergence warning: The first`100`

periods will have decreasing magnitude, convergence-related precision errors that can be as high as ~5% deviation in indicator values for earlier periods.

### HTTrendlineResult

name | type | notes |
---|---|---|

`date` | datetime | Date |

`trendline` | float, Optional | HT Trendline |

`dc_periods` | int, Optional | Dominant cycle periods (smoothed) |

`smooth_price` | float, Optional | Weighted moving average of `(H+L)/2` price |

### Utilities

See Utilities and Helpers for more information.

## Example

```
from stock_indicators import indicators
# This method is NOT a part of the library.
quotes = get_historical_quotes("SPY")
# Calculate HT Trendline
results = indicators.get_ht_trendline(quotes)
```

## About Hilbert Transform Instantaneous Trendline

Created by John Ehlers, the Hilbert Transform Instantaneous Trendline is a 5-period trendline of high/low price that uses signal processing to reduce noise. [Discuss] 💬