Ventana software support forum

Hi,
When I use NORMAL RANDOM function for demand, I get weird results when mean is 0 & min is also 0 at the same time. It seems to be using the logic applicable for https://en.wikipedia.org/wiki/Truncated ... stribution - as the final output has mean > 0 instead. Can someone confirm the logic used?
How can we model a true normal distribution (without min/max) & then apply the truncation separately using min/max functions? Any inputs are welcome.
Regards, Param

joined a model.
Use the synthesim and the sliders Under the constants to experiment how it works.

Regards.

JJ

In fact, the random normal function does not work, if both the minimum and the maximum are equal to the mean.
a second solution to this limitation, is if this happens, to force the minimum and maximum to extreme indetermined values and the standard deviation to 0, to make the function work.
See the second model that works that way.

Regards.

JJ

thanks @LAUJJL for your answers & samples. I'll try them out. appreciate your prompt help.

Taking

x = MIN(1,MAX(0,RANDOM NORMAL(-1000,1000,0,1,0)))

gives different results from

y = RANDOM NORMAL(0,1,0,1,0)

When you wrap the normal in MIN MAX, an out-of-range value gets truncated to the MIN or MAX endpoint. This causes a peak in the histogram at the ends. When the RANDOM NORMAL function exceeds the MIN MAX parameters, it resamples from the interval, yeilding a new random value that is within the range. This gives the usual truncated Normal distribution.

Correct - the logic matches the wiki page, which is the standard way of describing a truncated Normal in areas I'm familiar with.

You can use the NORMAL CDF function if you need to determine the mean realized from a particular combination of parameters.