function  toTextualDescription(degree){
    if ((degree>337.5 && degree<360)|| (degree>22.5 && degree<22.5))
    {return 'Northerly';}
    else if(degree>22.5 && degree<67.5){return 'North Easterly';}
    else if(degree>67.5 && degree<112.5){return 'Easterly';}
    else if(degree>122.5 && degree<157.5){return 'South Easterly';} 
    else if(degree>157.5 && degree<202.5){return 'Southerly';}
    else if(degree>202.5 && degree<247.5){return 'South Westerly';}
    else if(degree>247.5 && degree<292.5){return 'Westerly';}
    else if(degree>292.5 && degree<337.5){return 'North Westerly';}
}

.pdf on the above link you can find the direction representation, i want to change the degree to textual for as, North, NorthEast, East, SouthEast, South, south west, west , and Northwest could you suggest a better way of doing this.how can i improve it? i am using Javascript.

function  toTextualDescription(degree){
    if ((degree>337.5 && degree<360)|| (degree>22.5 && degree<22.5))
    {return 'Northerly';}
    else if(degree>22.5 && degree<67.5){return 'North Easterly';}
    else if(degree>67.5 && degree<112.5){return 'Easterly';}
    else if(degree>122.5 && degree<157.5){return 'South Easterly';} 
    else if(degree>157.5 && degree<202.5){return 'Southerly';}
    else if(degree>202.5 && degree<247.5){return 'South Westerly';}
    else if(degree>247.5 && degree<292.5){return 'Westerly';}
    else if(degree>292.5 && degree<337.5){return 'North Westerly';}
}

https://compuweather.com/files/2009/10/CompuWeather-Wind-Direction-Compass-Chart.pdf on the above link you can find the direction representation, i want to change the degree to textual for as, North, NorthEast, East, SouthEast, South, south west, west , and Northwest could you suggest a better way of doing this.how can i improve it? i am using Javascript.

• javascript

4 Answers 4

You do not need so many checks in if statements. Also, you do not need else if because return will end function execution in proper places.

function  toTextualDescription(degree){
    if (degree>337.5) return 'Northerly';
    if (degree>292.5) return 'North Westerly';
    if (degree>247.5) return 'Westerly';
    if (degree>202.5) return 'South Westerly';
    if (degree>157.5) return 'Southerly';
    if (degree>122.5) return 'South Easterly';
    if (degree>67.5) return 'Easterly';
    if (degree>22.5) return 'North Easterly';
    return 'Northerly';
}

let compassSector = ["N", "NNE", "NE", "ENE", "E", "ESE", "SE", "SSE", "S", "SSW", "SW", "WSW", "W", "WNW", "NW", "NNW", "N"];

weather.windDirection = compassSector[(data.wind.deg / 22.5).toFixed(0)];

Here's a way to do it with an array of sector names. This will also work for values < 0 and > 360

function toTextualDescription(degree) {
  var sectors = ['Northerly','North Easterly','Easterly','South Easterly','Southerly','South Westerly','Westerly','North Westerly'];
  
  degree += 22.5;

  if (degree < 0) 
    degree = 360 - Math.abs(degree) % 360;
  else 
    degree = degree % 360;
  
  var which = parseInt(degree / 45);
  return sectors[which];
}

console.log("0: " + toTextualDescription(0));
console.log("-30: " + toTextualDescription(-30));
console.log("900: " + toTextualDescription(900));
console.log("22.4999: " + toTextualDescription(22.4999));
console.log("22.5: " + toTextualDescription(22.5));
console.log("359: " + toTextualDescription(359));

This is from one of my projects, so the text is a bit different:

function deg_to_hdg( degrees ){
degrees = Math.floor( degrees / 22.5 )

return Array(
    'N',
    'NE',
    'NE',
    'E',
    'E',
    'SE',
    'SE',
    'S',
    'S',
    'SW',
    'SW',
    'W',
    'W',
    'NW',
    'NW',
    'N'
)[degrees];

}