lib/mopti/nelder_mead.rb in mopti-0.2.2 vs lib/mopti/nelder_mead.rb in mopti-0.2.3

@@ -59,11 +59,11 @@
     def each
       return to_enum(__method__) unless block_given?
 
       x = @x_init.dup
       n = x.size
-      max_iter = @max_iter || 200 * n
+      max_iter = @max_iter || (200 * n)
 
       alpha = 1.0
       beta = n > 1 ? 1 + 2.fdiv(n) : 2.0
       gamma = n > 1 ? 0.75 - 1.fdiv(2 * n) : 0.5
       delta = n > 1 ? 1 - 1.fdiv(n) : 0.5
@@ -88,17 +88,17 @@
       n_iter = 0
       while n_iter < max_iter
         break if ((sim[1..-1, true] - sim[0, true]).abs.flatten.max <= @xtol) && ((fsim[0] - fsim[1..-1]).abs.max <= @ftol)
 
         xbar = sim[0...-1, true].sum(0) / n
-        xr = xbar + alpha * (xbar - sim[-1, true])
+        xr = xbar + (alpha * (xbar - sim[-1, true]))
         fr = func(xr, @args)
         n_fev += 1
 
         shrink = true
         if fr < fsim[0]
-          xe = xbar + beta * (xr - xbar)
+          xe = xbar + (beta * (xr - xbar))
           fe = func(xe, @args)
           n_fev += 1
           shrink = false
           if fe < fr
             sim[-1, true] = xe
@@ -110,20 +110,20 @@
         elsif fr < fsim[-2]
           shrink = false
           sim[-1, true] = xr
           fsim[-1] = fr
         elsif fr < fsim[-1]
-          xoc = xbar + gamma * (xr - xbar)
+          xoc = xbar + (gamma * (xr - xbar))
           foc = func(xoc, @args)
           n_fev += 1
           if foc <= fr
             shrink = false
             sim[-1, true] = xoc
             fsim[-1] = foc
           end
         else
-          xic = xbar - gamma * (xr - xbar)
+          xic = xbar - (gamma * (xr - xbar))
           fic = func(xic, @args)
           n_fev += 1
           if fic < fsim[-1]
             shrink = false
             sim[-1, true] = xic
@@ -131,10 +131,10 @@
           end
         end
 
         if shrink
           (1..n).to_a.each do |j|
-            sim[j, true] = sim[0, true] + delta * (sim[j, true] - sim[0, true])
+            sim[j, true] = sim[0, true] + (delta * (sim[j, true] - sim[0, true]))
             fsim[j] = func(sim[j, true], @args)
             n_fev += 1
           end
         end