maael/node-data-preprocessing

var bigInt = require('big-integer');
var standardise = function(options, data) {
    options = options || {};
    options.path = options.path || '';
    options.format = options.format || 'csv';
    options.min = options.min || 0.1;
    options.max = options.max || 0.9;
    options.standardisationMethod = options.standardisationMethod || 'default';
    options.ignore = options.ignore || [];
    var column, min, max;
    for(var i = 0; i < data.length; i++) {
        if(options.ignore.indexOf(i) === -1) {
            column = data[i];
            if(typeof(column[0]) === 'object') {
                var mappedColumn = column.map(function(el, i) {
                    return { index: i, value: el };
                });
                mappedColumn.sort(function(a, b) {
                    return +(a.value.greater(b.value)) || +(a.value.equals(b.value)) - 1;
                });
                var sortedColumn = mappedColumn.map(function(el) {
                    return column[el.index];
                });
                max = sortedColumn[sortedColumn.length - 1];
                min = sortedColumn[0];
            } else {
                max = Math.max.apply(null, column);
                min = Math.min.apply(null, column);
            }
            for(var j = 0; j < column.length; j++) {
                data[i][j] = standardisation(options.standardisationMethod, min, max, column[j]);
            }
        }
    }
    return data;
};
function standardisation(type, min, max, value) {
    var result;
    switch(type) {
        case 'ss':
            result = ssStandardisation(min, max, value);
            break;
        case 'normal':
            result = normalStandardisation(min, max, value);
            break;
        default:
            result = defaultStandardisation(min, max, value);
    }
    return result;
}
function defaultStandardisation(min, max, value) {
    if(typeof(value) === 'object') {
        return 0.8 * ((value.subtract(min)).toJSNumber() / (max.subtract(min)).toJSNumber()) + 0.1;
    } else {
        return 0.8 * ((value - min)/(max - min)) + 0.1;
    }
}

function ssStandardisation(min, max, value) {

}

function normalStandardisation(min, max, value) {

}

module.exports = standardise;