private void button_Click(object sender, RoutedEventArgs e)
{
double theta_param = double.Parse(param1tb.Text);
double k = double.Parse(param2tb.Text);
int count = int.Parse(counttb.Text);
Accord.Statistics.Distributions.Univariate.GammaDistribution gd1 = new Accord.Statistics.Distributions.Univariate.GammaDistribution(theta_param, k);
double[] dd1 = gd1.Generate(count);
currGammaArray = dd1;
DistributionInstance dis = new DistributionInstance(currGammaArray);
dis.DParams.Add("theta", theta_param);
dis.DParams.Add("k", k);
currentDis = dis;
UpdateList(currentDis);
}
/// <summary>
/// Returns WGEN generated daily precipitation (inches) data for numDays number of days
/// </summary>
/// <param name="rndSeed">Random number generator seed</param>
/// <param name="PWW">One dimensional array(Month) of probabilities of a wet day following a wet day. Month: Month of the year.</param>
/// <param name="PWD">One dimensional array(Month) of probabilities of a wet day following a dry day. Month: Month of the year.</param>
/// <param name="alpha">One dimensional arry(Month) of Gamma Distribution Shape parameter. Month: Month of the year.</param>
/// <param name="beta">One dimensional arry(Month) of Gamma Distribution Scale parameter. Month: Month of the year</param>
/// <param name="numDays">Number of days for which precipitation is to be generated</param>
/// <param name="precip">One dimensional array[Day] of daily precipitation in inches</param>
/// <param name="errorMsg"></param>
private void GeneratePrecip(int rndSeed, double[] PWW, double[] PWD, double[] alpha, double[] beta, int numDays, out double[] precip, out string errorMsg)
{
errorMsg = "";
precip = new double[numDays];
int[] month = { 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364 };
Random rnd = new Random(rndSeed);
int mon = 0;
Accord.Statistics.Distributions.Univariate.GammaDistribution gamma = new Accord.Statistics.Distributions.Univariate.GammaDistribution(alpha[0], beta[0]);
Accord.Math.Random.Generator.Seed = rndSeed;
bool previousDayWet = false;
//Randomly decide if the first day is dry or wet
double rnd1 = rnd.NextDouble();
if (rnd1 > 0.5)
{
previousDayWet = true;
}
else
{
previousDayWet = false;
}
//If previous day is wet then assign it the precipitation amount by generating a random variate from Gamma Distribution
if (previousDayWet == true)
{
precip[0] = gamma.Generate();
}
int year = 0;
//Start the loop from 2nd day because the first day has already been decided
for (int i = 1; i < numDays; i++)
{
if ((i - year * 365) > month[mon]) //Check if month has changed
{
mon = mon + 1;
if (mon > 11)
{
mon = 1;
year = year + 1;
}
gamma = new Accord.Statistics.Distributions.Univariate.GammaDistribution(alpha[mon], beta[mon]); //Instantiate Gamma Distribution for the month
}
//Check if it is a wet or dry day
rnd1 = rnd.NextDouble();
if (previousDayWet == true)
{
if (rnd1 <= PWW[mon]) //wet day followed by a wet day
{
previousDayWet = true; //set for the next iteration
precip[i] = gamma.Generate();
}
else //wet day followed by a dry day
{
previousDayWet = false; //set for the next iteration
precip[i] = 0;
}
}
else //Previous day is dry
{
if (rnd1 <= PWD[mon]) //dry day follwoed by a wet day
{
previousDayWet = true; //set for the next iteration
precip[i] = gamma.Generate();
}
else //dry day followed by a dry day
{
previousDayWet = false;
precip[i] = 0; //set for the next iteration
}
}
}
return;
}