## 182 Reputation

4 years, 129 days

## How can the functional derivative/variat...

Maple 2021

Hello Everyone,

My questions is about a straight forward as my title suggests. I know how to compute the variation by hand and of course it is in plently of books, but I would like to know how I could possibly do it in Maple as I have some terms with non-trivial contributions where I infact need that specific variation.

I have attached my file I have been working with that has more comments.

RicciAction.mw

Thank you

## How can I Simplify in the physics packag...

Maple 2021

Hi MaplePrimes,

I am interested in obtaining some gravitational field equations from an action using the FunDiff command. I have been able to write what I think is a pretty short and quick worksheet(with an arbitrary metric) and I am easily able to obtain the Einstein Field Equations. However, when I introduce some new more complicated terms into the action and apply the Simplify command maple does not appear to be able to evaluate and I end up halting the computation. When I specify a metric Maple, for example Schwarzschild, Maple will easily be able to Simplify my expression but it will use metric components during the process. Where what I am interested in is just the Tensor expression with respective indices.

I was wondering if anyone had any thoughts on how I could resolve this.

I have attached the worksheet that I am working with. I look forward to your thoughts/comments.

Thank you.

ActionFieldEquations.mw

## Discrete Fourier transform(DFT) of Array...

Maple 2021

Hi Everyone,

I want to do some fourier analysis on a numeric ODE solution but first I wanted to understand all the commands and make sure it worked with a simple example. I created a Array of data which I attempted to take the DFT of but I got an error and I cannot seem to figure out why, I looked through the help pages and it looks like inputs use an Array of data but for some reason mine wont work.

Worksheet attached, any help greatly appreciated.

DFT_Test.mw

## How to solve a cubic assuming discrimina...

Maple 2021

Hi MaplePrimes.

I have a cubic with some parameters that I would like to solve and recieve 3 real solutions, however I cannot seem to find a way to get that to work while using assumptions. I always recieve 1 real and two complex conjugate answers. I have tried assuming the discrimant to be greater then zero but nothing seems to be working, and I have looked through a few posts on here but I cant seem to find anything out. In particular solve({f,conditions},{variable})

If I solve with a known set of paramters(which i determine graphically) that gives three solutions everything works fine. Also if I solve the cubic generally and recieve the two complex solutions and one real then substitute the paramters in I get the same correct answers, so I am slightly baffled. If I have missed something simple my apologies.

Any help would be greatly appreciated. File attached.

CubicSolve.mw

## Having trouble with discont=true in plot...

Maple 2017

Hello MaplePrimes,

So, I have used the discont=true option in the past and it has worked fine for me but for some reason with these functions I am using now the plots are still containing the veritcal asymptotes. Anyone spot something I am forgetting or doing incorrectly?

I have attached my maple file for easy viewing.

Thanks.

DiscontQuestion.mw

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