Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2000
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2000

[Date Index] [Thread Index] [Author Index]

Search the Archive

Could this be improved?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg21741] Could this be improved?
  • From: "Jordan Rosenthal" <jr at ece.gatech.edu>
  • Date: Wed, 26 Jan 2000 03:45:40 -0500 (EST)
  • Organization: Georgia Institute of Technology, Atlanta GA, USA
  • Sender: owner-wri-mathgroup at wolfram.com

Hi all,

I wrote the following code which works correctly.  I was wondering, however,
if there was a way of doing the same thing that had more of a Mathematica
approach.  I am new to Mathematica and am still trying to get a grasp on how
to program effectively within the environment.

myMtx[v_] := Module[
    {nCols, nRows, vPadded, c},
    nCols = Length[v];
    nRows = 2nCols - 1;
    c = ZeroMatrix[nRows, nCols];
    vPadded = PadRight[v, nRows, 0];
    For[i = 1, i <= nCols, i++,
      c[[All, i]] = vPadded;
      vPadded = RotateRight[vPadded]
      ];
    c
    ]

For example, myMtx[{1,2,3}] takes the vector {1,2,3} and turns it into the
matrix {{1, 0, 0}, {2, 1, 0}, {3, 2, 1}, {0, 3, 2}, {0, 0, 3}} which looks
like

[ 1 0 0 ]
[ 2 1 0 ]
[ 3 2 1 ]
[ 0 3 2 ]
[ 0 0 3 ]


Thanks,

Jordan






  • Prev by Date: Re: Product with p!=j
  • Next by Date: Re: Mathematica on the Web
  • Previous by thread: Re: Efficient Replacement Rules to Matrix?
  • Next by thread: Re: Could this be improved?