PS I am using 1.9.9CVS under windows XP
remaining faithful to my lazy approach :-) I add to the discussion rather
than checking in other environments.
Explaining how I discovered the point may help: I was trying to generalise a
script written by somebody else for cases when both matrices involved were
bound to be non-scalars, to inclu
On Sat, 8 Dec 2012, Riccardo (Jack) Lucchetti wrote:
> On Fri, 7 Dec 2012, Allin Cottrell wrote:
>
>> In fact, although we could go either way in terms of resolving the
>> inconsistency of treatment of X'Y and X'*Y, for X or Y 1x1 and not
>> strictly conformable with the other operand, it would be
On Fri, 7 Dec 2012, Allin Cottrell wrote:
> In fact, although we could go either way in terms of resolving the
> inconsistency of treatment of X'Y and X'*Y, for X or Y 1x1 and not
> strictly conformable with the other operand, it would be easier (I
> think) to make the latter operation reduce to t
On 12/07/2012 11:08 PM, Allin Cottrell wrote:
> On Fri, 7 Dec 2012, Sven Schreiber wrote:
>
>> On 12/07/2012 08:31 PM, Alan G Isaac wrote:
>>> On 12/7/2012 1:52 PM, Summers, Peter wrote:
But your example holds true whether or not we write x'y or x'*y
>>>
>>>
>>> Absolutely. I was addressing
On 12/07/2012 08:31 PM, Alan G Isaac wrote:
> On 12/7/2012 1:52 PM, Summers, Peter wrote:
>> But your example holds true whether or not we write x'y or x'*y
>
>
> Absolutely. I was addressing only the issue of
> how to handle a 1 x 1 matrix, not the core question.
>
> I agree that many matrix p
On Sat, 8 Dec 2012, Sven Schreiber wrote:
> On 12/07/2012 11:08 PM, Allin Cottrell wrote:
>> On Fri, 7 Dec 2012, Sven Schreiber wrote:
>>
>>> On 12/07/2012 08:31 PM, Alan G Isaac wrote:
On 12/7/2012 1:52 PM, Summers, Peter wrote:
> But your example holds true whether or not we write x'y o
1x1 matrix. Are you suggesting that both treatments should
give an error? I'm willing to be persuaded, but that is inconsistent with other
languages.
-Original Message-
From: gretl-users-bounces(a)lists.wfu.edu
[mailto:gretl-users-bounces(a)lists.wfu.edu] On Behalf Of
sers-bounces(a)lists.wfu.edu
[mailto:gretl-users-bounces(a)lists.wfu.edu] On Behalf Of Alan G Isaac
Sent: Friday, December 07, 2012 12:48 PM
To: Gretl list
Subject: Re: [Gretl-users] pre-multiplication by transpose
On 12/7/2012 12:25 PM, Summers, Peter wrote:
> I'd argue that a 1x1 matrix
produce the identical result (6*I(3)).
Matlab doesn't allow the x'y operation -- only x'*y.
PS
-Original Message-
From: gretl-users-bounces(a)lists.wfu.edu
[mailto:gretl-users-bounces(a)lists.wfu.edu] On Behalf Of Allin Cottrell
Sent: Friday, December 07, 2012 11:
On Fri, 7 Dec 2012, Sven Schreiber wrote:
> On 12/07/2012 08:31 PM, Alan G Isaac wrote:
>> On 12/7/2012 1:52 PM, Summers, Peter wrote:
>>> But your example holds true whether or not we write x'y or x'*y
>>
>>
>> Absolutely. I was addressing only the issue of
>> how to handle a 1 x 1 matrix, not t
On 12/7/2012 1:52 PM, Summers, Peter wrote:
> But your example holds true whether or not we write x'y or x'*y
Absolutely. I was addressing only the issue of
how to handle a 1 x 1 matrix, not the core question.
I agree that many matrix programming languages special case
the 1x1 matrix. I guess
On 12/7/2012 12:58 PM, Summers, Peter wrote:
> But associativity assumes all products are well-defined. A*(B*C) in your
> example generates an error because B*C fails.
Indeed.
That is the point of the example.
On 12/7/2012 12:25 PM, Summers, Peter wrote:
> I'd argue that a 1x1 matrix should be treated as a scalar in any computations
So what is "right" is what is clearly wrong?
E.g., (1x2)*((2x1)*(2x2)) -> error (as it should be)
but ((1x2)*(2x1))*(2x2) -> (2x2)
So much for associativity.
Alan Isaac
Am 07.12.2012 12:22, schrieb Stefano Fachin:
> I bumped into a feature of Hansl that may be produce puzzling results:
> using the "pre-multiplication by transpose" notation X'Y with X a 1x1
> matrix (that is, defined as a matrix, but with 1 row and 1 column, for
> instance because the result of the
I bumped into a feature of Hansl that may be produce puzzling results:
using the "pre-multiplication by transpose" notation X'Y with X a 1x1
matrix (that is, defined as a matrix, but with 1 row and 1 column, for
instance because the result of the product of a row vector for a column
vector) pro
On Fri, 7 Dec 2012, Sven Schreiber wrote:
> Am 07.12.2012 12:22, schrieb Stefano Fachin:
>> I bumped into a feature of Hansl that may be produce puzzling results:
>> using the "pre-multiplication by transpose" notation X'Y with X a 1x1
>> matrix (that is, defined as a matrix, but with 1 row and 1
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