# Uniform_pdf in Dynare

Hi everyone

Because I belive that variance of shock is always positive number and it ranges with 0.001 to 10, then I give a uniform as the prior distribution for variance of shock as following
stderr eps_muzhat,0.001,10, uniform_pdf, ;

But Dynare does not work
Can anyone explain for that whether I use the incorrect syntax?

You need to provide mean and standard deviation. In your case, it would simply be
`stderr eps_muzhat,uniform_pdf, (10+0.001)/2,(10-0.001)/sqrt(12);`

Or you can skip the prior mean and standard deviation, and write instead:

``````stderr eps_muzhat, uniform_pdf, , , 0.001, 10;
``````

It is imperative define a uniform prior with the lower and upper bounds .Obviously this only works with the uniform prior. All this is explained in the reference manual.

Best,
Stéphane.

Thank you so much Prof. @jpfeifer
Now it runs. At the beginning I misunderstood the syntax

Dear @stepan-a
Thank you much for your another suggestion about syntax
It is also very convenient