nightfury7 / universalbasics.js

src/ub.arrays.stats.js

/** global: UB */

/*! ARRAY UTILS */

var arrayFuncs = {
	
	unique: function(output = null){
		var list = this;
		return list.deleteDuplicates(output);
	},
	deleteDuplicates: function(output = null){
		var list = this;
		
		if (output == null) {
			output = [];
		}
		
		var o = output.length;
		
		for (var i = 0, il = list.length;i<il;i++){
			var item = list[i];
			
			if(item != null){
				if(output.indexOf(item) === -1) {
					output[o++] = item;
				}
			}
		}
		return output;     
	},
	
	/** Generate a 2D array of all possible combinations, given a 1D array of any values.
		
		eg : INPUT : [A, B, C]
		eg : OUTPUT : [ [A], [B], [A,B], [C], [A,C], [B,C], [A,B,C] ] */
	combinations: function(list){
		var list = this;
		var result = [];
		var listSize = list.length;
		var combinationsCount = (1 << listSize);
		
		for (var i = 1;i<combinationsCount;i++){
			var combination = [];
			for (var j = 0;j<listSize;j++){
				if ((i & (1 << j))){
					combination.push(list[j]);
				}
			}
			result.push(combination);
		}
		return result;
	},
	
	mostFrequent: function(returnAnyValIfAllFreqSame = true, fallback = 0){
		var list = this;
		
		// exit quickly if empty
		if (!list.Exists()) {
			return 0;
		}
		if (list.length === 1) {
			return list[0];
		}
		
		
		// calc number of occurences
		var unique = list.unique();
		var counts = UB.newArray(0, list.length);
		var maxCount = 0;
		var maxIndex = 0;
		for (var i = 0, il = list.length;i<il;i++){
			var val = list[i];
			if (val != null) {
				
				// find val and count it
				var index = unique.indexOf(val);
				counts[index]++;
				
				// find highest frequency
				var curCount = counts[index];
				if (maxCount < curCount) {
					maxCount = curCount;
					maxIndex = index;
				}
				
			}
		}
		
		// if all frequencies same (max frequency was 1) .. and custom val wanted back
		if (!returnAnyValIfAllFreqSame && maxCount == 1) {
			return fallback;
		}
		
		// return the most frequent item
		return unique[maxIndex];
	},
	leastFrequent: function(returnAnyValIfAllFreqSame = true, fallback = 0){
		var list = this;
		
		// exit quickly if empty
		if (!list.Exists()) {
			return 0;
		}
		if (list.length === 1) {
			return list[0];
		}
		
		// calc number of occurences
		var unique = list.unique();
		var counts = UB.newArray(0, list.length);
		var maxCount = 0;
		for (var i = 0, il = list.length;i<il;i++){
			var val = list[i];
			if (val != null) {
				
				// find val and count it
				var index = unique.indexOf(val);
				counts[index]++;
				
				// find highest frequency
				var curCount = counts[index];
				if (maxCount < curCount) {
					maxCount = curCount;
				}
				
			}
		}
		
		// if all frequencies same (max frequency was 1) .. and custom val wanted back
		if (!returnAnyValIfAllFreqSame && maxCount == 1) {
			return fallback;
		}
		
		// return the most frequent item
		return unique[counts.indexOfMin()];
	},
	
	total: function(start=0, end=-1) {
		var vals = this;
		
		// exit quickly if few items .. and checking full array
		var len = vals.length;
		if (end === -1) {
			end = len - 1;
		}
		if (len === 0 || start > end) {
			return 0;
		}
		
		// slowly check all values
		if (vals.length === 0) {
			return 0;
		}
		var sum = 0;
		for (var i = start; i <= end; i++) {
			
			// skip nulls
			var val = vals[i];
			if (val != null){
				var num = val;
				sum += num;
			}
		}
		return sum;
	},
	
	max: function(start=0, end=-1) {

This code seems to be duplicated in your project.

		var vals = this;
		
		// exit quickly if few items .. and checking full array
		var len = vals.length;
		if (end === -1) {
			end = len - 1;
		}
		if (len === 0 || start > end) {
			return 0;
		}
		
		// check all values
		var big = Number.NEGATIVE_INFINITY;
		var found = 0;
		for (var i = start; i <= end; i++) {
			
			// skip nulls
			var val = vals[i];
			if (val != null) {
				found++;
				var num = val;
				if (num > big) {
					big = num;
				}
			}
		}
		
		// exit if no non-null values found
		if (found === 0) {
			return 0;
		}
		
		// return calculated max value
		return big;
	},
	
	indexOfMax: function(start=0, end=-1) {

This code seems to be duplicated in your project.

		var vals = this;
		
		// exit quickly if few items .. and checking full array
		var len = vals.length;
		if (end === -1) {
			end = len - 1;
		}
		if (len === 0 || start > end) {
			return -1;
		}
		
		// check all values
		var big = Number.NEGATIVE_INFINITY;
		var slot = -1;
		var found = 0;
		for (var i = start; i <= end; i++) {
			
			// skip nulls
			var val = vals[i];
			if (val != null) {
				found++;
				var num = val;
				if (num > big) {
					big = num;
					slot = i;
				}
			}
		}
		
		// exit if no non-null values found
		if (found === 0) {
			return -1;
		}
		
		// return calculated max value
		return slot;
	},
	
	min: function(start=0, end=-1) {

This code seems to be duplicated in your project.

		var vals = this;
		
		// exit quickly if few items .. and checking full array
		var len = vals.length;
		if (end === -1) {
			end = len - 1;
		}
		if (len === 0 || start > end) {
			return 0;
		}
		
		// check all values
		var small = Number.POSITIVE_INFINITY;
		var found = 0;
		for (var i = start; i <= end; i++) {
			
			// skip nulls
			var val = vals[i];
			if (val != null){
				found++;
				var num = val;
				if (num < small) {
					small = num;
				}
			}
			
		}
		
		// exit if no non-null values found
		if (found === 0) {
			return 0;
		}
		
		// return calculated min value
		return small;
	},
	
	indexOfMin: function(start=0, end=-1) {

This code seems to be duplicated in your project.

		var vals = this;
		
		// exit quickly if few items .. and checking full array
		var len = vals.length;
		if (end === -1) {
			end = len - 1;
		}
		if (len === 0 || start > end) {
			return -1;
		}
		
		// check all values
		var small = Number.POSITIVE_INFINITY;
		var slot = -1;
		var found = 0;
		for (var i = start; i <= end; i++) {
			
			// skip nulls
			var val = vals[i];
			if (val != null){
				found++;
				var num = val;
				if (num < small) {
					small = num;
					slot = i;
				}
			}
			
		}
		
		// exit if no non-null values found
		if (found === 0) {
			return -1;
		}
		
		// return calculated min value
		return slot;
	},
	
	avg: function(start=0, end=-1) {
		var vals = this;
		
		// exit quickly if few items .. and checking full array
		var len = vals.length;
		if (end === -1) {
			end = len - 1;
		}
		if (len === 0 || start > end) {
			return 0;
		}
		
		// slowly check all values
		return vals.total(start, end) / ((end - start)+1);
	},
			
	nearest: function(value, start=0, end=-1) {

This code seems to be duplicated in your project.

		var arr = this;
		
		// quickly exit if few values
		if (arr.length === 0) {
			return value;
		}
		if (arr.length === 1) {
			return arr[0];
		}
		
		// returns the nearest value
		var dists = [];
		if (end === -1) {
			end = arr.length - 1;
		}
		for (var a = start; a <= end; a++) {
			dists.push(arr[a].distance(value));
		}
		var index = dists.indexOfMin();
		return arr[start + index];
	},
	
	indexOfNearest: function(value, start=0, end=-1) {

This code seems to be duplicated in your project.

		var arr = this;
		
		// quickly exit if few values
		if (arr.length === 0) {
			return -1;
		}
		if (arr.length === 1) {
			return 0;
		}
		
		// returns the index of the nearest value
		var dists = [];
		if (end === -1) {
			end = arr.length - 1;
		}
		for (var a = start; a <= end; a++) {
			dists.push(arr[a].distance(value));
		}
		var index = dists.indexOfMin();
		return (start + index);
	},
	
	height: function(start=0, end=-1) {
		var arr = this;
		return arr.max(start, end) - arr.min(start, end);
	},

	none:null
};

// register funcs
UB.registerFuncs(Array.prototype, arrayFuncs);