Prefer the Spirit look for matrices

[StuartBruff]

Initial impression, after looking at the *few*
worksheets that are limited to Spirit's
capabilities, is that I prefer Spirit's look for
matrices, in particular the way that it vertically
aligns numbers according to magnitude. I also
like the square brackets.

Not so sure about overloading the double bar
operator to be the determinant; the single bar is
commonly used and should at least be a user
display choice.

In addition, the double bar is a common option for
norms, sometimes with subscripts to distinguish
the type of norm.

As far as standards go, the ISO 31-11 uses the
double bar for norm, but uses the explicit name
'det' for determinant and the single bar (but it's
shown applied to elements of a matrix rather than
the matrix symbol). I've quite a few references
that use 'det', so it would good to have this
option as well (which goes back to a long-standing
request of mine to have a named version of every
operator).

Stuart

The attached file shows the difference in
appearance. It also shows the negative effect upon
wide worksheets.

[TomGutman]

What a mess! I agree that the double bar for determinant makes no sense and is contrary to normal mathematical usage. The positioning of the regions is all messed up, with massive overlaps. And text attributes (bold, here) seem not to carry over -- only the actual text.

I would consider the results of loading this sheet into MC' to be useful only as a starting point for a massive reworking of the sheet. Not usable as it stands.
__________________
� � � � Tom Gutman

[mzeftel]

We are switching to single | for determinant and using the || for norm of a vector.

Mona

[TomGutman]

What sort of "norm"? Mathcad should follow normal mathematical notation as far as possible. It is standard usage to use the single | to represent the magnitude of a vector. Mathcad should not deviate from that. The double || is used for the norm of a matrix (where the single | is used for determinant) and is the only place Mathcad should use it.
__________________
� � � � Tom Gutman

[Ninetrees]

Perhaps have a box to the lower right of the || || that can contain at least several specific optional characters, and if none is specified, the default is 2?

Rich
http://www.downeastengineering.com/

[StuartBruff]

On 9/18/2009 9:08:23 PM, woodwise wrote:
== Perhaps have a box to the lower right of the ||
|| that can contain at least several specific
optional characters, and if none is specified, the
default is 2?

Sounds reasonable. Strictly, the 2 is unnecessary
for the Euclidean norm (ISO 31-12:1992 11-11.10),
but they could implement it in the same way that
the Σ operator has been done (default
behaviour if a place-holder is empty), leaving the
author to deal with any ambiguities according to
need/convention.

It's also worth noting that, in practice, both ||
& | are used for the vector norm, and matrix norms
are defined for both square and rectangular
matrices; ISO 31-12:1992 11-13.2 gives
|a| as the preferred choice (along
with a) but allows ||a|| for
the magnitude of a vector.

Stuart

[PhilipLeitch]

And I agree with your comment about standards.

It would be great if Mathcad could specify which standards it uses and/or intends to use.

Otherwise it ends up being "this is what we use because this is what we use"


Philip
___________________
Nobody can hear you scream in Euclidean space.

[SteenGroðe]

Or better: Implement any standard combined with user options.

Steen Gro�e