Our Charting software plots the data you give it. It is up to you to define the data points you intend to plot.
For a normal curve, you would create x and y vectors containing data points sampled along the normal curve for your range of X-values, fixed mean, and fixed standard deviation. Then create a SimpleDataset and plot the points using a SimpleLinePlot.
The normal distribution is defined by the following equation:
Normal equation. The value of the random variable Y is:
Y = [ 1/Sigma * sqrt(2*PI) ] * e-(x - Mean)^2/2*Sigma^2
See http://stattrek.com/Lesson2/Normal.aspx
where X is a normal random variable,Mean is the mean,Sigma is the standard deviation, PI is approximately 3.14159, and e is approximately 2.71828.
Something similar to the code below will plot a normal distribution (sampled at 100 points) 5 standard deviations to the left and right of the given mean.
double[] normalx = new double[100];
double[] normaly = new double[100];
double normv = 0;
double xval = 0;
double mean = 10;
double stddev = 1;
for ( i = 0; i < normalx.Length; i++)
{
xval = mean - 5 * stddev + i * (5 * stddev) / 50;
normv = Math.Exp(-0.5 * Math.Pow((xval - mean) / stddev, 2)) * (1.0 / (stddev * Math.Sqrt(2.0 * Math.PI)));
normalx[i] = xval;
normaly[i] = normv;
}
SimpleDataset normDataset;
normDataset = new SimpleDataset("NormDataset", normalx, normaly);
SimpleLinePlot normPlot = new SimpleLinePlot(pTransform1, normDataset, attrib1);
chartVu.AddChartObject(normPlot);
Normal distribution (Gaussian) graph
Posted - 04 Jun 2009 : 02:07:53
