add evaluation counting to ARS, cleanup

ars.lua

@@ -63,6 +63,8 @@ function Ars:init(dims, popsize, poptop, learning_rate, sigma, antithetic)
     if self.antithetic then self.popsize = self.popsize * 2 end
 
     self._params = nn.zeros(self.dims)
+
+    self.evals = 0
 end
 
 function Ars:params(new_params)
@@ -113,8 +115,13 @@ function Ars:ask(graycode)
 end
 
 function Ars:tell(scored, unperturbed_score)
+    local use_lips = unperturbed_score ~= nil and self.antithetic
+    self.evals = self.evals + #scored
+    if use_lips then self.evals = self.evals + 1 end
+
+    -- FIXME: the non-antithetic case seems to be broken.
+
     local indices = collect_best_indices(scored, self.poptop, self.antithetic)
-    --print("best trials:", indices)
 
     local top_rewards = {}
     for i = 1, #scored do top_rewards[i] = 0 end
@@ -123,16 +130,6 @@ function Ars:tell(scored, unperturbed_score)
         top_rewards[sind + 0] = scored[sind + 0]
         top_rewards[sind + 1] = scored[sind + 1]
     end
-    --print("top:", top_rewards)
-
-    if self.antithetic then
-        local top_delta_rewards = {} -- only used for printing.
-        for i, ind in ipairs(indices) do
-            local sind = (ind - 1) * 2 + 1
-            top_delta_rewards[i] = abs(top_rewards[sind + 0] - top_rewards[sind + 1])
-        end
-        --print("best deltas:", top_delta_rewards)
-    end
 
     local step = nn.zeros(self.dims)
     local _, reward_dev = calc_mean_dev(top_rewards)
@@ -147,7 +144,7 @@ function Ars:tell(scored, unperturbed_score)
             if reward ~= 0 then
                 local noisy = self.noise[i]
 
-                if unperturbed_score ~= nil then
+                if use_lips then
                     local lips = kinda_lipschitz(noisy, pos, neg, unperturbed_score)
                     reward = reward / lips / self.sigma
                 else