Re: Mathematica 6.0 easier for me ... (small review)

*To*: mathgroup at smc.vnet.net*Subject*: [mg76586] Re: [mg76457] Mathematica 6.0 easier for me ... (small review)*From*: János <janos.lobb at yale.edu>*Date*: Thu, 24 May 2007 06:09:26 -0400 (EDT)*References*: <200705230859.EAA23180@smc.vnet.net>

> 4. At work, I haven't had to resort to other programs because > Mathematica wasn't the best choice. This is extremely nice. BTW, > There's a "temporal" advantage with procedural programming that hasn't > been apparant to me in functional or rule. Still working on it. Maybe > someone can help. If I have > lis={{1,10},{2,10},...{9,10},{11,20},{12,20}...{19,20} > > How do I use functional and/or rule to determine where the second > number (lis[[i,2]]) jumped from 10 to 20 to 30 and save the pair. > Assuming there was noise, I only want to store the first 10->20, then > look for 20->30 and so on. So in time, I want my search to change as > I progress through the list. Any input appreciated! Here is a newbie approach: In[36]:= lst = Table[{Random[Integer, {1, 100}], Random[ Integer, {9, 31}]}, {i, 1000}]; In[37]:= ctl = {10, 20, 30, 40}; In[40]:= First[Last[Reap[i = 1; j = 1; While[i <= Length[lst], If[lst[[i,2]] == ctl[[j]], Sow[{i, lst[[i]]}]; j++; , Null]; i++; ]]]] Out[40]= {{3, {99, 10}}, {115, {49, 20}}, {127, {20, 30}}} First part of an element show what position the element occurred in lst, the second part is the element itself. J=E1nos ---------------------------------------------- Trying to argue with a politician is like lifting up the head of a corpse. (S. Lem: His Master Voice)

**References**:**Mathematica 6.0 easier for me ... (small review)***From:*Paul@desinc.com