Re: Tag List Protected error

*To*: mathgroup at smc.vnet.net*Subject*: [mg113774] Re: Tag List Protected error*From*: niobe <ben.carbery at gmail.com>*Date*: Thu, 11 Nov 2010 06:11:47 -0500 (EST)*References*: <ib5u05$c0j$1@smc.vnet.net> <ib8csq$2fn$1@smc.vnet.net>

> Could you provide a x, y pair that reproduce this error? x={{7, 9, 0, 0, 10}, {4, 0, 3, 10, 9}, {4, 9, 0, 5, 0}, {0, 2, 1, 8, 5}, {2, 5, 3, 4, 4}, {1, 0, 4, 0, 0}, {1, 10, 6, 8, 9}} y={{4, 5}, {3, 1}, {2, 6}} > I would avoid using ReplacePart. If I understand your example > correctly... > > y is a ragged array: {{row}, {col0, col1}} Think of x as a lists of quantities and y as rules for adjusting them. So in this example of y, decrement x[[4,3]] by 2, increment x[[5,3]] by 2, increment x[[4,1]] by 6, decrement x[[5,1]] by 6, But the point is that the operation works when not delayed. It seems like the way command is being parsed is the problem as Mathematica is thinking that the ReplacePart syntax is actual an operation on one of the arguments. I am hoping there is a way to force the correct interpretation.