Anthrazit

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These are questions asked by Anthrazit

Is it possible to use the ~ when using Matrix multiplications, where the second part of the operand are list elements?

The first part of the matrix multiplication remains unchanged, while the second one should be each element of the list.

The result should be a list of vectors / matrices again.

with(Units:-Simple)

alpha := 20*Unit('arcdeg')

20*Units:-Unit(arcdeg)

(1)

TransMatrix := Matrix([[cos(alpha), sin(alpha)], [-sin(alpha), cos(alpha)]])

Matrix(%id = 36893490153509525972)

(2)

pt := Vector(2, {(1) = -25.0, (2) = 0.})

Vector[column](%id = 36893490153504789076)

(3)

ptlist := [Vector(2, {(1) = -25.0, (2) = 0.}), Vector(2, {(1) = 25.0, (2) = 0.})]

[Vector[column](%id = 36893490153504761724), Vector[column](%id = 36893490153504761844)]

(4)

pt_trans := evalf(TransMatrix.pt)

Vector[column](%id = 36893490153514236012)

(5)

pl_translist := evalf(TransMatrix.ptlist)

Matrix(%id = 36893490153509525972).[Vector[column](%id = 36893490153504761724), Vector[column](%id = 36893490153504761844)]

(6)

TransMatrix.ptlist

Error, number of dimensions must be the same for all container objects in an elementwise operation

 

NULL

Download MatrixMultiplicate.mw

Is it correct that element wise operators just work on the first element, and not in nested elements?

Do I need to manually go through the nested lists, or are there any other tricks to simplify this operation?

fasteners := [Vector(2, {(1) = -25.0*Units:-Unit(mm), (2) = 0.}), Vector(2, {(1) = 25.0*Units:-Unit(mm), (2) = 0.})]

[Vector[column](%id = 36893490765018711092), Vector[column](%id = 36893490765018711212)]

(1)

`~`[convert](fasteners, unit_free)

[Vector[column](%id = 36893490764941411500), Vector[column](%id = 36893490764941411620)]

(2)

x := Vector(2, {(1) = -25.0*Units:-Unit(mm), (2) = 0.})

Vector[column](%id = 36893490765009212828)

(3)

`~`[convert](x, unit_free)

Vector[column](%id = 36893490764944766844)

(4)

NULL

Download elementwise.mw

Just wonder if there are any known issues when using dots in Maple code attachment names?

Only issue so far that I can see is that error messages are split a bit strange.

I know that this is not really a question regarding core Maple package, but I am running into problems during the installation process.

After having upgraded Maple networktools as mentioned, I am unable to run the activation program due to an error.

"Java Virtual Machine Launcher: Error: Could not create the Java Virtual Machine."

I've never had that problem before in previous versions. There was no Java installed on the (virtual) server, so I installed the latest OpenJDK to check if that solved the problem.

Unfortunately it didn't.

Any hints would be appreciated.

Windows Server 2012R2

Don't know if this is a bug or just another proof of my incompetence, but I am struggling in storing values between sessions using DataTable components.

The problem seems to me to be related to nested tables, somehow.

I've made a little example showing the problem.

Quickly explained, you should do 2 runs to see the problem. The first run creates a matrix and a table, and stores the values in a DataTable cell. You shouldn't see any problems there.

Save the document and close it.

Then open the file once again, but just run the 2 commands in chapter 4. You should then see an error message.

My goal is to be able to save a nested variables with its values in a Datatable between sessions. The main variable and many of them below are tables, the last in the branch often string values or numbers with units.

StoreBetweenSessions.mw

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