Re: normalize a table

*To*: mathgroup at smc.vnet.net*Subject*: [mg72809] Re: normalize a table*From*: Bill Rowe <readnewsciv at sbcglobal.net>*Date*: Sat, 20 Jan 2007 03:52:51 -0500 (EST)

On 1/19/07 at 1:01 AM, ruth.lazkoz at ehu.es (Ruth) wrote: >I want to do something really simple, which is take a table made of >pairs and normalize the first number in each pair by dividing by the >largest. >For instance, I want to transform this list >{{1,0.2},{2,0.3},{3,0.4},{4,0.5}} >into this one >{{1/4, 0.2}, {1/2, 0.3}, {3/4, 0.4}, {1, 0.5}} >The way i did it is through the chain of commands First, getting the divisor can be done as In[2]:= data={{1,0.2},{2,0.3},{3,0.4},{4,0.5}}; In[3]:= scale=Max[First/@data] Out[3]= 4 then, the desired result can be achieved with pattern matching as: In[4]:= data/.{a_,b_}->{a/scale,b} Out[4]= {{1/4, 0.2}, {1/2, 0.3}, {3/4, 0.4}, {1, 0.5}} or functional programming as In[5]:= {First@#/scale,Last@#}&/@data Out[5]= {{1/4, 0.2}, {1/2, 0.3}, {3/4, 0.4}, {1, 0.5}} -- To reply via email subtract one hundred and four