int get_local_windchill( double temperature, double humidity, double windpower )
{
double tmptemp = temperature;
double tmpwind = windpower;
double windchill = 0;
if( tmptemp < 50 ) {
/// Model 1, cold wind chill (only valid for temps below 50F)
/// Is also used as a standard in North America.
// Temperature is removed at the end, because get_local_windchill is meant to calculate the difference.
// Source : http://en.wikipedia.org/wiki/Wind_chill#North_American_and_United_Kingdom_wind_chill_index
windchill = 35.74 + 0.6215 * tmptemp - 35.75 * ( pow( tmpwind,
0.16 ) ) + 0.4275 * tmptemp * ( pow( tmpwind, 0.16 ) ) - tmptemp;
if( tmpwind < 4 ) {
windchill = 0; // This model fails when there is 0 wind.
}
} else {
/// Model 2, warm wind chill
// Source : http://en.wikipedia.org/wiki/Wind_chill#Australian_Apparent_Temperature
tmpwind = tmpwind * 0.44704; // Convert to meters per second.
tmptemp = temp_to_celsius( tmptemp );
windchill = ( 0.33 * ( ( humidity / 100.00 ) * 6.105 * exp( ( 17.27 * tmptemp ) /
( 237.70 + tmptemp ) ) ) - 0.70 * tmpwind - 4.00 );
// Convert to Fahrenheit, but omit the '+ 32' because we are only dealing with a piece of the felt air temperature equation.
windchill = windchill * 9 / 5;
}
return windchill;
}
/**
* Print temperature (and convert to celsius if celsius display is enabled.)
*/
std::string print_temperature( double fahrenheit, int decimals )
{
std::ostringstream ret;
ret.precision( decimals );
ret << std::fixed;
if(get_option<std::string>( "USE_CELSIUS" ) == "celsius") {
ret << temp_to_celsius( fahrenheit );
return string_format( pgettext( "temperatur in Celsius", "%sC" ), ret.str().c_str() );
} else {
ret << fahrenheit;
return string_format( pgettext( "temperatur in Fahrenheit", "%sF" ), ret.str().c_str() );
}
}
/**
* Print temperature (and convert to celsius if celsius display is enabled.)
*/
std::string print_temperature( double fahrenheit, int decimals )
{
std::ostringstream ret;
ret.precision( decimals );
ret << std::fixed;
if(OPTIONS["USE_CELSIUS"] == "celsius") {
ret << temp_to_celsius( fahrenheit );
return rmp_format( _( "<Celsius>%sC" ), ret.str().c_str() );
} else {
ret << fahrenheit;
return rmp_format( _( "<Fahrenheit>%sF" ), ret.str().c_str() );
}
}
double temp_to_kelvin( double fahrenheit )
{
return temp_to_celsius( fahrenheit ) + 273.15;
}
