RE: matrix operations
- To: mathgroup at smc.vnet.net
- Subject: [mg46352] RE: [mg46329] matrix operations
- From: "tgarza01 at prodigy.net.mx" <tgarza01 at prodigy.net.mx>
- Date: Mon, 16 Feb 2004 08:59:53 -0500 (EST)
- Reply-to: tgarza01 at prodigy.net.mx
- Sender: owner-wri-mathgroup at wolfram.com
Probably the best way (or at least a good one) would be
In[1]:=
aMat = {{1, 3, 2, 4}, {4, 6, 1, 0}, {3, 6, 9, 2}};
In[2]:=
Drop[RotateLeft[aMat] - aMat, -1]
Out[2]=
{{3, 3, -1, -4}, {-1, 0, 8, 2}}
Tomas Garza
Mexico City
Original Message:
-----------------
From: paolo tarpanelli tarpanelli at libero.it
To: mathgroup at smc.vnet.net
Subject: [mg46352] [mg46329] matrix operations
If I have a matrix
a={x[[1,1]],x[[1,2]],...,x[[1,n]]}
{x[[2,1]],x[[2,2]],...,x[[2,n]]}
.
.
.
{x[[m,1]],x[[m,2]],...,x[[m,n]]}
how can I compute the difference between any element and the previous for
each column :
aa={x[[2,1]]-x[[1,1]], x[[2,2]]-x[[1,2]],...,x[[2,n]]-x[[1,n]]}
{x[[3,1]]-x[[2,1]], x[[3,2]]-x[[2,2]],...,x[[3,n]]-x[[2,n]]}
.
.
.
{x[[m,1]]-x[[m-1,1]],x[[m,2]]-x[[m-1,2]],...,x[[m,n]]-x[[m-1,n]]}
----------------------------------------------------------------------------
--------------------------
I built this code but it does not work
r=Array[0,{m,n}]
For[j=1,j=n,j++
r[[i,j]]=Table[a[[i+1,j]]-a[[i,j]],{i,1,m-1,1}]]
thanks
Paolo
----------------
--------------------------------------------------------------------
mail2web - Check your email from the web at
http://mail2web.com/ .