Nodejs Array Mean mean()

Method Source Code

Array.prototype.mean = function(){ 
   return this.reduce(function(previousMean, currentValue, i){
      return previousMean + (1/(i + 1))*(currentValue - previousMean);
   });//from  w w  w .  j  a  va 2s.  com
};

Array.prototype.median = function() {
    var values = this;
    values.sort( function(a,b) {return a - b;} );
 
    var half = Math.floor(values.length/2);
 
    if(values.length % 2){
        return values[half];
    } else {
        return (values[half-1] + values[half]) / 2.0;
    }
};

Array.prototype.max = function(){
   return this.reduce(function(p,n){ 
      if(n > p || p === null){ 
         return n;
      } else {
         return p;
      }
   },null);
};

Array.prototype.min = function(){
   return this.reduce(function(p,n){ 
      if(n < p || p === null ){ 
         return n;
      } else {
         return p;
      }
   },null);
};

Array.prototype.sum = function(){
   return this.reduce(function(p,n){
      return p + n;
   }, 0);
};

Related

1. mean()

   Array.prototype.mean = function() {
       return !this.length ? 0
           : this.reduce(function(pre, cur, i) {
               return (pre * i + cur) / (i + 1);
               });
   console.log( [1,2,3,4,5].mean() );   
   console.log( [].mean() );            
   

2. mean()

   Array.prototype.mean = function () {
     var sum = this.reduce(
       function (prev, cur) {
         return prev + cur;
     );
     return sum / this.length;
   

3. mean()

   Array.prototype.mean = function () {
       var sum = this.reduce(function(previousValue, currentValue) {
           return previousValue + currentValue;
       });
       return sum / this.length;
   };
   

4. mean()

   Array.prototype.mean = function() {
       mean = 0;
       for (var i = 0; i < this.length; i++) {
           mean += this[i];
       mean = mean / this.length;
       return mean;
   };
   

5. mean()

   Array.prototype.mean = function() {
     var length = this.length;
     return this.total()/length;
   };
   

6. mean()

   Array.prototype.mean = function(){
       return this.sum()/this.length;
   Array.prototype.sum = function(){
     var ret = this[0];
     for(var i=1;i<this.length;i++){
       ret += this[i]
     return ret;
   ...