485075_en-US

liliconcom

Simulations

Hi
How do I create a simulation with a relative standard deviation for the input factors? 

 

 

Advanced Statistical ModelingRe: Simulations

You can't, if I understand your question. You are definition sampling distributions for the input variables or factors. The standard deviation is in terms of the variable, using the same units. You can convert a relative measure, such as % CV, by multiplying the RSD by the mean.

 

I might have completely misunderstood your question.

Re: Simulations

What I want to do is to estimate the defect rate where one of the input variables is the mass with a relative standard deviation of +/- 2%. The input range for the mass is 20-100 kg. 

Re: Simulations

Can you help with this JSL expression? How do I define SD from the actual setting and RSD? 

Re: Simulations

We are going in circles. The Profiler uses a fixed factor set point (e.g., W/T = 0.55 above ). It uses this value as the location of the chosen distribution, and it does not change during the simulation. It uses the spread (e.g., W/T SD = 0.03 above) to generate random deviates based on a selected distribution (e.g., normal distribution). If you have a RSD, say 5%, then the absolute SD is RSD * Location = 0.05 * 0.55 = 0.0275.

 

The choice of Expression allows you to use any valid JSL expression that returns a number. For example:

 

Random Normal( 50, 5 );

 

Will generate normally distributed deviates from a normal population with a location of 50 and a spread of 5. You could replace either the constant location or the constant spread or both with another expression that varies the value deterministically or randomly. I do not know how you would use this ability because you still have not answered my previous questions.

 

See the documentation for the Profiler Simulator factor settings.