Re: Creating a new table using values from a column in another table,

*To*: mathgroup at smc.vnet.net*Subject*: [mg66362] Re: Creating a new table using values from a column in another table,*From*: "J Siehler" <jsiehler at gmail.com>*Date*: Thu, 11 May 2006 02:14:00 -0400 (EDT)*References*: <e3sgqp$lsf$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Here's a sample data table and two possible ways to do what you want, one based on mapping, one based on a replacement rule. In[1]:= data=Table[{Prime[n],Random[]},{n,15}] Out[1]= {{2,0.736809},{3,0.106457},{5,0.165311},{7,0.137037},{ 11,0.0934996},{13,0.0962497},{17,0.253369},{19,0.973479},{23,0.953613},{29,\ 0.819286},{31, 0.603322},{37,0.487691},{41,0.392807},{43,0.550309},{47,0.249372}} In[3]:= {First@#,f@First@#}&/@data Out[3]= {{2,f[2]},{3,f[3]},{5,f[5]},{7,f[7]},{11,f[11]},{13,f[13]},{17,f[17]},{19, f[19]},{23,f[23]},{29,f[29]},{31,f[31]},{37,f[37]},{41,f[41]},{43, f[43]},{47,f[47]}} In[4]:= data/.{a_,b_}:>{a,f[a]} Out[4]= {{2,f[2]},{3,f[3]},{5,f[5]},{7,f[7]},{11,f[11]},{13,f[13]},{17,f[17]},{19, f[19]},{23,f[23]},{29,f[29]},{31,f[31]},{37,f[37]},{41,f[41]},{43, f[43]},{47,f[47]}} Wonko the Sane wrote: > Hi all, > > I have a question that I have not been able to work out myself, and so > put it to the group to help. I have a set of data points in a table (2 > columns {{x1,y1},{x2,y2},....,{xn,yn}}) I have performed a fit to the > data and have a function f[x] which I would now like to evaluate at each > data point (column 1 of the first table) to get a new table > {{x1,f[x1]},{x2,f[x2]},....,{xn,f[xn]}}. Is there a way to do this? I > hope my request is clear > > Best Regards > Michael