# What are the coordinates of the following points in a CCD? a. central point (Blue round sign) b. the N axis point (Red round sign) c. 2N-f factorial points located at the corners (Yellow round sign)Does it change with the type of Distribution Function used (Gaussian or Uniform?)

 The PDDOEL documentation indicates the points are based on probabilityso the location would be based on the design variable distribution.If the variable has a gaussian distribution (PDVAR,,GAUS) then the probabilitieswill be based on a Gaussian distribution. If the variable is uniform (PDVAR,,UNIF)then the probabilities will be based on a uniform distribution. This can be verifiedby looking at the sample points used in the database (file.pds) or in the sample file (file.samp).For example, if a random variable has a gaussian distribution with mean of 10 andstandard deviation of 1, the sample values will be at the following locations.Probability Level = .005 ( - 2.58 sigma ) => 7.42Probability Level = .05 ( - 1.65 sigma) => 8.35Probability Level = .50 ( 0 sigma) => 10.00Probability Level = .95 ( +1.65 sigma) = 11.65Probability Level = .995 ( +2.58 sigma) = 12.58