Phi: Calculates the angle, in degrees, that the wind affects the...
In Bolshom/optimumtt: A colection of functions to help cyclists.

Description Usage Arguments Details Value Author(s) Examples

By evaluating the direction that a certain cyclist is going, and getting the wind bearing, it's possible to calculate this angle phi.

1	Phi(Ta, La, Tb, Lb, date)

`Ta`	Latitude of the origin point.
`La`	Longitude of the origin point.
`Tb`	Latitude of the destination point.
`Lb`	Longitude of the destination point.
`date`	Date and time to get the weather report. Check example for input format.

To use the package "darksky" to collect weather report, you must activate the API with your key. Check https://darksky.net/dev for more info.

phi

The angle at which the wind affects the cyclist, in degrees.

Natan Freitas Leite

## The function is currently defined as
function (Ta, La, Tb, Lb, date)
{
    phi = abs(ang_head(Ta, La, Tb, Lb) - climate(Ta, La, date)[4])
    return(phi)
  }

##latitude (T) and longitude (L) for S<c3><a3>o Francisco, Niter<c3><b3>i, Brazil
##cycling circuit:
Ta=-22.915396
La=-43.095511
Tb=-22.934862
Lb=-43.101902
##date to get the wind direction in relation to the cyclist
##"AAAA-MM-DDThh:mm:ss"
date="2017-04-02T07:00:00"
##result
phi=Phi(Ta,La,Tb,Lb,date)
phi