title: no method matching setindex : trying to change matrix values
body: <p>Using Julia, I've defined a 9x10 matrix of zeros, and am trying to change a single entry , but I get the error <code>'setindex!' has no method matching setindex!(::Float64, ::Float64, ::Int64)</code></p>
  
  <p>My code is:</p>
  
  <pre><code>m = zeros(9,10)
  m[1][1] = 1.0
  </code></pre>
  
  <p>with the error pointing to the second line. <code>typeof(m)</code> is an <code>Array{Float64,2}</code>, which, as far as I can tell is mutable.</p>
  
  <p>What am I doing wrong here?</p>