title: Reaching maximum number of solver variables?
body: <p>I'm using excel solver for an optimization problem (maximization using the evolutionary/genetic algorithm). Yet, I didn't had any problems after setting bottom and top boundaries for perhaps 3-4 input variables and about 1,000 samples. The fitness function is quite simple, just the sum of all outputs called. Is I used to have a (1000 x 4) input matrix and a corresponding (1000 x 1) output column vector.</p>
  
  <p>Now, I have 42 input variables (<a href="https://www.solver.com/standard-excel-solver-dealing-problem-size-limits" rel="nofollow noreferrer">which is less than the maximum size of variables solver should handle</a>). Unfortunately, the GA doesn't find a optimal solution (it filters out all outputs; so i get just #NA called from my column vector). I know from 'trying-out' that changing just one variable improves model fitness. So Solver/GA seems to have problems running the 'hill climbing'.</p>
  
  <p>Empirically, I figured out that 14 variables set as bottom threshold) or 5+5 variables set as bottom + top threshold are the maximum Solver can deal with.
  Settings are pretty standard and I checked different modifications.</p>
  
  <p>Constraint Precision: 0.001 - 0.000001
  Scaling: On / Off</p>
  
  <p>Convergence (GA): 0.001 - 0.000001
  Population Size: 0, 100, 200
  Mutation Rate: 0.01, 0.075, 0.2, 0.5, 0.9</p>
  
  <p>After ~40 iterations it stops and no outputs has been called (100% filtered out).</p>
  
  <p>Has someone else experienced this issue? Did I reached the limits of Excel solver or the GA? If yes, is there a solution solving my problem in Excel or do I have to Matlab/Python library, which can deal with so many variables?</p>