title: How can I give a constant value to a variable in julia
body: <p>I have a 2 dimensional matrix variable which it should get a constant value. for example</p>
  
  <pre><code>@variable(model1,x[h=1:3,6]==I[h=1:3,6])
  </code></pre>
  
  <p>I: is a constant matrix. but in code it gives this error:</p>
  
  <pre><code>ERROR: MethodError: no method matching constructvariable!(::JuMP.Model, ::JuMP.#_error#103{Tuple{Sym
  bol,Expr}}, ::Array{Float64,2}, ::Array{Float64,2}, ::Symbol, ::String, ::Float64)
  </code></pre>
  
  <p>would you please help me? thank you</p>