Monte carlo sampling: range of design variable

Hello everyone,

I have two design variables(amp,pw) that have special ranges. Amp is [0.05,0.8], pw is [10p,1n], and I want to sweep these two variables use monte carlo in adexl instead of normal sweep with uniform distance. I just dont know whether what I have done is right or not...

I wrote a .scs file, and included it in corners setup:

statistics {

    process {

           vary amp dist=unif N=0.45

           vary pw dist=unif N=490e-12

} 

}

And I'm not sure about how to set a sampling range for these two parameters. In the spectre user guide, I found this:

So in global variable settings, I set pw to 500p, and amp to 0.5 to set the "mean" in the previous picture. And the range of two parameters are [500p-490p,500p+490p] and [0.5-0.45,0.5+0.45],right? And I didnt set design variables in the corners setup. 

So is my settings right? Thanks for your reply and suggestions in advance.

Regards,

Holz