Re: General--Difficulties in Understanding Mathematica Syntax

*To*: mathgroup at smc.vnet.net*Subject*: [mg69043] Re: General--Difficulties in Understanding Mathematica Syntax*From*: AES <siegman at stanford.edu>*Date*: Mon, 28 Aug 2006 02:54:43 -0400 (EDT)*Organization*: Stanford University*References*: <ecrbsu$pc5$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

In article <ecrbsu$pc5$1 at smc.vnet.net>, Bill Rowe <readnewsciv at earthlink.net> wrote: > lBut the code with Map is simpler since I do not need to worry about > indexing. For example, a typical error when coding with For loops to index an > array is to be one off, i.e., using say greater as the stopping criteria when > it should have been greater than or equal. Since indexing is never explicitly > coded with Map, this error cannot happen. I do agree with the underlying point in this comment. The gimmick I've learned to always use with indexing is more or less the following. If I'm doing a problem that involves say stepping over values of an independent variable x ranging from 0 to xmax -- or more generally from xmin to xmax -- I start by defining an x array using xArray = Table[x, {xmin, xmax, (xmax-xmin)/nSteps]} ] and then never touch a specific index or use [[ ]] notation again. Plotting of results is done using ListPlot[Transpose[{ xArray, resultArray} ]