brightwind.analyse.analyse.sector_ratio

brightwind.analyse.analyse.sector_ratio(wspd_1, wspd_2, wdir, sectors=72, min_wspd=3, direction_bin_array=None, boom_dir_1=-1, boom_dir_2=-1, return_data=False)

Calculates the wind speed ratio of two wind speed time series and plots this ratio, averaged by direction sector, in a polar plot using a wind direction time series. The averaged ratio by sector can be optionally returned in a pd.DataFrame.

If boom directions are specified, these will be overlaid on the plot. A boom direction of ‘-1’ assumes top mounted and so doesn’t plot.

Parameters

  • wspd_1 – First wind speed time series. This is divisor.

  • wspd_2 – Second wind speed time series, dividend.

  • wdir (pandas.Series) – Series of wind directions

  • sectors (int) – Set the number of direction sectors. Usually 12, 16, 24, 36 or 72.

  • min_wspd – Minimum wind speed to be used.

  • direction_bin_array – (Optional) Array of numbers where adjacent elements of array form a bin. This overwrites the sectors.

  • boom_dir_1 (float) – Boom direction in degrees of wspd_1. If top mounted leave default as -1.

  • boom_dir_2 (float) – Boom direction in degrees of wspd_2. If top mounted leave default as -1.

  • return_data (bool) – Set to True if you want the data returned.

Type

wspd_1: pandas.Series

Type

wspd_2: pandas.Series

Type

min_wpd: float

Returns

A wind speed ratio plot showing the average ratio by sector and scatter of individual data points.

Return type

plot, pandas.DataFrame

Example usage

import brightwind as bw
data = bw.load_csv(bw.datasets.demo_data)

#For plotting both booms
bw.sector_ratio(data.Spd80mN, data.Spd80mS, wdir=data.Dir78mS, boom_dir_1=0, boom_dir_2=180)

#For plotting no booms
bw.sector_ratio(data.Spd80mN, data.Spd80mS, wdir=data.Dir78mS)

#If one boom is top mounted, say Spd80mS
bw.sector_ratio(data.Spd80mN, data.Spd80mS, wdir=data.Dir78mS, boom_dir_2=180)

#To use your custom direction bins, for example (0-45), (45-135), (135-180), (180-220), (220-360)
bw.sector_ratio(data.Spd80mN, data.Spd80mS, wdir=data.Dir78mS,
                direction_bin_array=[0, 45, 135, 180, 220, 360], boom_dir_1=0, boom_dir_2=180)