Thank all help help. Ted's intuitive single step definition is what I want.
I try to teach elementary Linear Algebra using R to manupilate matrices.
Since my students have no programming experience at all, any fancy and
muliple step definition in matrix row operation will confuse them. Again, I
a
On Sat, Aug 28, 2010 at 1:32 AM, Cheng Peng wrote:
>
> Sorry for possible misunderstanding:
>
> I want to define a matrix (B) based on an existing matrix (A) in a single
> step and keep A unchanged:
>
>> #Existing matrix
>> A=matrix(1:16,ncol=4)
>> A
> [,1] [,2] [,3] [,4]
> [1,] 1 5 9
Hi:
Here are some functions for computing elementary matrices so that you can do
Gauss elimination the hard way (the easy way is the LU decomposition, but I
digress) I wouldn't use these for serious work, since there are no
checks for matrix instability, but the essential ideas are there. It
On Aug 28, 2010, at 2:54 AM, Joshua Wiley wrote:
Is this sufficiently single steppish for you?
D <- A <- matrix(1:16, 4)
D[3, ] <- 2 * D[1, ] + D[3, ]
# Alternately, you could do this
# but it is much messier, and I do not see how
# two steps is really an issue
# you want to end up with two m
Is this sufficiently single steppish for you?
D <- A <- matrix(1:16, 4)
D[3, ] <- 2 * D[1, ] + D[3, ]
# Alternately, you could do this
# but it is much messier, and I do not see how
# two steps is really an issue
# you want to end up with two matrices anyways
# so it's not like you save memory by
Sorry for possible misunderstanding:
I want to define a matrix (B) based on an existing matrix (A) in a single
step and keep A unchanged:
> #Existing matrix
> A=matrix(1:16,ncol=4)
> A
[,1] [,2] [,3] [,4]
[1,]159 13
[2,]26 10 14
[3,]37 11 15
[4,]4
On Aug 28, 2010, at 12:29 AM, Cuckovic Paik wrote:
Thanks for respose.
you still used two steps to get the new matrix tst2:
For Pete"s sake! Can't you see that I didn't _need_ to use tst2. The
same operations would have worked on tst. I was just using tst2
because I wanted to be able to
Thanks for respose.
you still used two steps to get the new matrix tst2:
step 1: tst2 = tst
step 2: perform the row operation in tst2.
Can you do this in a single step?
A similar example:
> tst
[,1] [,2] [,3] [,4]
[1,]159 13
[2,]26 10 14
[3,]37 11
On Aug 27, 2010, at 9:21 PM, Cuckovic Paik wrote:
I'm not absolutely sure I know what you mean by elementary row
operations ... you are supposed to offer test cases and specify the
desired output on r-help to support the aging faculties of the helpeRs
in this case ... having only the v
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