@dharr I think you are right, élément (1,1) should be a b - b a, not 0, an issue to adress.

@ecterrab Hi, a Dirac comb is very useful in Physics, signal processing, numerical applicatons… So yes, defining a new function “DiracComb” would be useful. However, I would say that the priority is the ability to go back and forth between the exponential and the Dirac form:

Since convert/exp is already settled, it is mainly missing convert/Dirac.

I think Standard Model (SM) is a beautiful development. It is nice to see that Maple is at the state of the art in Physics. This will be useful to many. For those not directly requiring SM, I am sure it has been the opportunity for many improvements in the surrounding.

@eager0626 Could you please post a worksheet. Also I am using Maple 2021.2 with the lastest Physics up-date:

https://www.maplesoft.com/products/maple/features/physicsresearch.aspx

Hi,

Using diff in the Physics framework might help. Once physics is loaded, z and conjugate(z) are considered as indepent variable allowing many derivative computation. The reason is that this is needed for functional derivative to recover equations from a given Lagrangian.

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/PhysicsDiff.mw .
 

Download PhysicsDiff.mw

This workaround is of potential interest to some people. It is then welcomed. Thanks to Edgardo for the huge effort in developing the Physics package at the cutting edge of CAS technology.

@Carl Love Thanks, that’s good to be aware of these potential issues.

@mmcdara I tried it in code edit region. There is a warning suggesting to declare `` as a local variable. If done so, the warning disapear, so yes, it is seems it is considered as a variable.

@mmcdara Interesting, thanks. Indeed, when working with a large number of input and output, with this solution, there is less writing and need to count. The interpretation is simpler as well (especially when used with Matlab).

@Rouben Rostamian  All good, thanks!

@tomleslie However, it seems to not be general

restart;
test:= proc():
   return a,b,c:
end proc:

B,C:=test()[2..3]
                          B, C := b, c

B:=test()[2];
                             B := b

A,C := test()[1,3];
Error, invalid subscript selector

@tomleslie Hi, thanks, good solution!

Hi,

That's a very nice post, which will be useful to many people, congratulations!

You could try to slightly modify the initialization as follows (of course, that’s just a matter of preferences).

restart;
with(Physics):
with(Physics[Vectors]):
with(PDEtools):
interface(imaginaryunit = i):
CompactDisplay((E__field_, B__flux_, H__field_, D__flux_)(x, y, z, t));

In addition, Setup(mathematicalnotation = true) is not required anymore, as it is the default for recent releases.

To get (4.4.11) from (4.4.10), entering "(4.4.10) . (4.4.10)" with a dot as the scalar product gives an equivalent result.

@Carl Love Impressive, thanks!

@acer Thanks! That's exactly what I need.