Minimise error: Variable domain should be Reals or Integers?

Questions
1

Hi, any idea how to resolve this error?

Minimize::vdom: Variable domain {ps} should be either Reals or Integers.

Screenshot2022-10-30at9.53.20pm.jpg
Screenshot2022-10-30at9.53.20pm.jpg1858×258 56.2 KB

The code

Minimize[(svccoef*ststddev*
Sqrt[dcproclt + transportlt + storeproclt]) 
+ (Ceiling[(stfreq*ads), ps]/2) + minpres, 
1 <= ps <= 48, Element[{ps}, Integers], {ps}] // N
2

It would help if you could provide the values of all of the other symbols used in the expression. Are you sure ps is not already set to some value? Try ClearAll[ps].

3

Hi, I’ve changed all the variables to specific values to remove any unknowns. I’ve also cleared ps as you mentioned. Still coming up with the same error:. The code is now:

Minimize[(1.64*1*Sqrt[3 + 1 + 1]) + (Ceiling[(7*5), ps]/2) + 6, 
   1 <= ps <= 48, 
   Element[{ps}, Integers], 
   {ps}] // N;

Minimize::vdom

4

Multiple constraints on the variable (here, ps) are written with And (&&) between them.

A minor change gets your code to work.

In[1]:= Minimize[{(1.64*1*Sqrt[3 + 1 + 1]) + (Ceiling[(7*5), ps]/2) + 6, 
          1 <= ps <= 48 && Element[ps, Integers]}, ps]
Out[1]= {27.1672, {ps -> 1}}
5

That fixed it, thanks so much!