问使用Node.js根据特定的分布在1到100之间生成随机变量

EN

var desiredMin = 1; //the desired minimum random result 
var desiredMax = 50; //the desired maximum random result 
var scale = 1; //Weibul scale parameter (1 provides an inverse result set)
var shape = 10; //Weibul shape parameter (how skewed the result set is)

//given an possible random range of {0,1} value calculate the minimum and maximum Weibull distribution values given current shape and scale parameters
var weibullMin = Math.pow((shape*scale), (-1*shape)) * Math.pow(.000001, shape -1) * Math.exp(Math.pow((.000001/scale), shape));
var weibullMax = Math.pow((shape*scale), (-1*shape)) * Math.pow(.999999, shape -1) * Math.exp(Math.pow((.999999/scale), shape));

//simulate 1000 random weibull values and write results to file
fileStream.once('open', function(fd) {
    for(var i = 1; i <= 1000; i++) {
        var r = Math.random();
        var weibullRandom = Math.pow((shape*scale), (-1*shape)) * Math.pow(r, shape-1) * Math.exp(Math.pow((r/scale), shape)); //generate Weibull random value
        var weibullRandomAdjusted = desiredMin + (desiredMax - desiredMin)*((weibullRandom-weibullMin) / (weibullMax - weibullMin)); //adjust Weibull random value so that it constrained into the desired min/max range
        fileStream.write(weibullRandomAdjusted + "\n");
    };
    fileStream.end();
});