## 219 Reputation

17 years, 22 days

## multipliying nonconformable matrices sho...

Maple 2021

I made an error by trying to multiply two nonconformable matrices. I think, I should receive an error message. But in this example this did not occur.

Strange.mw

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Matrices nonconformable, Maple should give error message:

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hereafter results are correct: Matrices

nonconformable, therefore error messages appear.

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Error, (in LinearAlgebra:-Multiply) first matrix column dimension (16) <> second matrix row dimension (4)

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Error, (in LinearAlgebra:-Multiply) first matrix column dimension (16) <> second matrix row dimension (4)

## indexed versus symbol...

Maple

I don't know how to fix this. What's wrong? Is there an alternative way to include underscores in a cat command?

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## input for Hessian in package VectorCalcu...

Maple 2020

Using the VectorCalculus package in Maple 2020.2, the Jacobian does accept my target function, whereas the Hessian does not. Both the Jacobian and the Hessian need an algebraic expression for its input.

What can I do to make it work?

kind regards, Harry

vectorcalculus_question.mw

## Linear Algebra package incompatable with...

Maple

I am using Maple 2020.2 and it seems that the Linear Algebra package is incompatable with the Vector Calculus package:

Why not a friendly error message?
I want to use the Jacobian and the Hessian. Are there alternatives? MTM package can give a Jacobian, but no Hessian (but MTM is also tricky to use).

Harry

## RootOf interpretation...

Maple

I was hoping to find a nice symbolic solution for the root of this equation:

a,c,d,k are parameters.
Unfortunately, I got an RootOf expression, which does not make sense to me. Assumptions do no help me further.

Next week, I have to present my results, but I don't know how to interpret is (the help file does not bring any relief). Is there something to say about the root? Suppose, I wanted to use side restriction on a problem? E.g., find a solution conditional on the fact that the derivative is zero.

Clearly, in the plot it seems simple.

In one case there is a solution Maple provides: a  (a parameter)

This seems strange, because numerically there is one solution (and clearly not a).

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 User Interface: 1502365          Kernel: 1502365         Library: 1502365
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 Originally a, renamed a~:   is assumed to be: RealRange(Open(0),infinity) Originally k, renamed k~:   is assumed to be: RealRange(Open(0),infinity) Originally t, renamed t~:   is assumed to be: RealRange(Open(0),Open(21))
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Now, numerically:

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