RandomReal gets stuck
- To: mathgroup at smc.vnet.net
- Subject: [mg100264] RandomReal gets stuck
- From: Bas Straatman <bastraat at ucalgary.ca>
- Date: Fri, 29 May 2009 21:00:42 -0400 (EDT)
- Organization: The University of Calgary
Hi, For a simulation of a stochastic process I am making use of RandomReal. I noticed that at some point during the simulation the output of RandomReal[] becomes fixed. For some reason, totally beyond my comprehension, every time after I execute an optimization the RandomReal[] generates the same series of random numbers: In[217]:= optimalactivity Out[217]= {24, 336/25, 616/25, 32/5, 28/5, 76/25, 4, 8, 8, 4/5, 0, 0, \ 0, 0, 0, 4/5, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \ 0, 0, 0, 0, 0, 12, 28, 80, 0, 104/3, 0, 234/125, 0, 0, 0, 0, 4, 0, 0, \ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} In[218]:= RandomReal[] Out[218]= 0.455719 In[219]:= RandomReal[] Out[219]= 0.977826 In[220]:= RandomReal[] Out[220]= 0.943215 In[221]:= RandomReal[] Out[221]= 0.962216 In[222]:= RandomReal[] Out[222]= 0.302348 In[223]:= optimalactivity Out[223]= {24, 336/25, 616/25, 32/5, 28/5, 76/25, 4, 8, 8, 4/5, 0, 0, \ 0, 0, 0, 4/5, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \ 0, 0, 0, 0, 0, 12, 28, 80, 0, 104/3, 0, 234/125, 0, 0, 0, 0, 4, 0, 0, \ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} In[224]:= RandomReal[] Out[224]= 0.455719 In[225]:= RandomReal[] Out[225]= 0.977826 In[226]:= RandomReal[] Out[226]= 0.943215 In[227]:= RandomReal[] Out[227]= 0.962216 In[228]:= RandomReal[] Out[228]= 0.302348 optimalactivity simpy calculates an optimum allocation of resources: optimalactivity := Table[y[i], {i, Length[inputmatrix]}] /. Maximize[ Plus @@ (Table[y[i], {i, Length[inputmatrix]}].(outputmatrix - inputmatrix))[[consumables - 2]], CONDITIONS , Table[y[i], {i, Length[inputmatrix]}]][[2]] There is no SeedRandom[] anywhere to be found. Any ideas how this is possible? Thanks. Bas Straatman