Re: Import variable and data

*To*: mathgroup at smc.vnet.net*Subject*: [mg32706] Re: [mg32682] Import variable and data*From*: BobHanlon at aol.com*Date*: Thu, 7 Feb 2002 05:09:32 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

In a message dated 2/6/02 6:07:58 AM, mvdv at bigfoot.com writes: >I'm having trouble with the following variable and data import: >The import file is input.txt: > >a b c d >1 23 45 678 > >inputData=Import[input.txt,"Table"] >{{a,b,c,d},{1,23,45,678}} > >This all works OK. >Head[..] indicates the a,b,c and d are strings, which is fine, because >ToExpression[..] changes them to symbols. What I'd like to do is use >inputData to do the following: > >{a,b,c,d}={1,23,45,678} > >However, if I try > >ToExpression[ inputData[[1]] ] = inputData[[2]] > >I get an error: > >Set::write: Tag ToExpression in ToExpression[a] is Protected. > >If I then enter 'a' in Mathematica I do not get 1 returned! No matter >how I try I >can't work it so that when I enter the symbol 'a' in Mathematica I get >the value >from inputData[[2]]. > Attributes[Set] {HoldFirst, Protected, SequenceHold} The lhs must be evaluated Evaluate[ToExpression[inputData[[1]]]]=inputData[[2]]; Bob Hanlon Chantilly, VA USA