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2024-03-12 10:56:14 +0200 answered a question the plot of my function EFF is always zero, but print

Use plot(lambda x: EEF(x, 2), x, 0, 3) See the detailed explanations from cell 28 in this tutorial notebook: https:/

2024-03-11 11:30:40 +0200 commented question Can't install SageMath 10.2 with conda

Maybe the discussion in this thread is relevant: https://groups.google.com/g/sage-devel/c/GaQHdu0Q6UU

2024-02-29 07:53:30 +0200 received badge  Nice Answer (source)
2024-02-28 11:49:56 +0200 answered a question Combine sage plot with matplotlib

What about something like c_matplotlib = c.matplotlib(figure=fig, sub=ax)

2024-02-28 11:20:08 +0200 edited answer Confused about covariant derivatives and tensors in SageMath

SageMath's covariant derivatives are documented at https://doc.sagemath.org/html/en/reference/manifolds/sage/manifolds/d

2024-02-28 11:02:20 +0200 answered a question Confused about covariant derivatives and tensors in SageMath

SageMath's covariant derivatives are documented here: https://doc.sagemath.org/html/en/reference/manifolds/sage/manifold

2024-02-19 21:49:48 +0200 commented question Comparison between SageMath ODE solvers and Scipy ODE solvers

Note that the geodesic solver already implemented in SageMath allows one to choose between many ODE solvers, from SciP

2024-02-19 21:49:14 +0200 commented question Comparison between SageMath ODE solvers and Scipy ODE solvers

Note that the geodesic solver already in SageMath allows one to choose between many ODE solvers, from SciPy or from the

2024-02-19 21:48:39 +0200 commented question Comparison between SageMath ODE solvers and Scipy ODE solvers

Note that the geodesic solver already implemented in SageMath allows one to choose between many ODE solvers, from SciPy

2024-02-19 21:48:23 +0200 commented question Comparison between SageMath ODE solvers and Scipy ODE solvers

Note that the geodesic solver already implemented in SageMath allows one to choose between many ODE solvers, from SciPy

2024-02-19 21:46:45 +0200 commented question Comparison between SageMath ODE solvers and Scipy ODE solvers

Note that the geodesic solver already implemented in SageMath allows one to choose between many ODE solvers, from SciPy

2024-02-17 21:20:51 +0200 answered a question Is it possible to use a Bitmap Image as a Graphics object?

FWIW, it is possible to superpose a SageMath plot to a png image, via Matplotlib. The first step is to convert the plot

2024-01-18 07:55:20 +0200 received badge  Nice Answer (source)
2024-01-13 14:38:44 +0200 answered a question Computing the Chern–Pontryagin invariant

You have to access to the tensor components by directly passing the indices to the operator [], not via a string (as @to

2024-01-03 15:16:09 +0200 commented answer Connection Forms not Anti-Symmetric

Indeed, if the frame argument is not provided, the connection 1-forms are computed for the manifold's default frame, see

2024-01-03 15:15:39 +0200 commented answer Connection Forms not Anti-Symmetric

Indeed, if the frame argument is not provided, the connection 1-forms are computed for the manifold's default frame, see

2023-12-24 14:56:28 +0200 edited answer How can I connect Jupyter with SageMath kernel?

You must have the Ubuntu package sagemath-jupyter installed on your system. Then you should launch Jupyter from the Sage

2023-12-24 14:28:15 +0200 answered a question How can I connect Jupyter with SageMath kernel?

You must have the Ubuntu package sagemath-jupyter installed on your system. Then you should launch Jupyter from the Sage

2023-12-24 14:06:40 +0200 answered a question Command matrix() not work, but worked before

It works for me with SageMath 10.2. Are you sure you are running a SageMath kernel and not a Python kernel? If yes, plea

2023-12-09 11:08:43 +0200 answered a question Plotting transition-of-transition fails with "cannot evaluate symbolic expression"

Hi, The composition transit_H_to_X = transit_Y_to_X * transit_H_to_Y works well for me (Sage 10.2): it yields a result

2023-12-05 09:43:43 +0200 commented question How to collect the derivatives in an expression for a scalar field

It should be diff(f)[i].expr() for $\partial f /\partial x^i$, so I guess commutator_f.expr().collect(diff(f)[0].expr()

2023-12-02 12:08:38 +0200 answered a question cannot use .str() on kernel of Matrix ?

You can use str(k) to get a string representation of k.

2023-11-29 08:59:04 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

Actually, since $\Xi := 1 + H_0^2 a^2$ is a constant, one can rescale the $t$ of https://arxiv.org/abs/1805.00243 as $t'

2023-11-29 08:57:23 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

Actually, since $\Xi := 1 + H_0^2 a^2$ is a constant, one can rescale the $t$ of https://arxiv.org/abs/1805.00243 as $t'

2023-11-29 08:57:13 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

Actually, since $\Xi := 1 + H_0^2 a^2$ is a constant, one can rescale the $t$ of https://arxiv.org/abs/1805.00243 as $t'

2023-11-29 08:56:50 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

Actually, since $\Xi := 1 + H_0^2 a^2$ is a constant, one can rescale the $t$ of https://arxiv.org/abs/1805.00243 as $t'

2023-11-29 08:55:51 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

Actually, since $\Xi := 1 + H_0^2 a^2$ is a constant, one can rescale the $t$ of https://arxiv.org/abs/1805.00243 as $t'

2023-11-29 08:54:49 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

Actually, since $\Xi := 1 + H_0^2 a^2$ is a constant, one can rescale the $t$ of https://arxiv.org/abs/1805.00243 as $t'

2023-11-29 08:54:27 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

Actually, since $\Xi := 1 + H_0^2 a^2$ is a constant, one can rescale the $t$ of https://arxiv.org/abs/1805.00243 as $t'

2023-11-29 08:46:12 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

I think that the metric given by Eq. (1) of your reference (https://arxiv.org/abs/1710.00997) is not correct (compare wi

2023-11-28 20:07:57 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

I think that the metric given by Eq. (1) of your reference (https://arxiv.org/abs/1710.00997) is not correct (compare wi

2023-11-28 15:26:45 +0200 edited answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

The 5-dimensional Kerr-AdS spacetime has been treated there. The Riemann tensor was computed in a reasonable time (it i

2023-11-28 15:02:06 +0200 edited answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

The 5-dimensional Kerr-AdS spacetime has been treated there. The Riemann tensor was computed in a reasonable time (it i

2023-11-28 13:20:54 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

Sorry I read your post too fast. I have updated my answer to the Kerr-de Sitter case.

2023-11-28 12:15:58 +0200 commented answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

I have updated my answer to the Kerr-de Sitter case.

2023-11-28 12:14:56 +0200 edited answer I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

The 5-dimensional Kerr-AdS spacetime has been treated there. The Riemann tensor was computed in a reasonable time (it i

2023-11-28 10:22:33 +0200 commented question I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

[2]: M = Manifold(4, 'M', latex_name=r'\mathcal{M}', structure='Lorentzian') [3]: BL.<t,r,th,ph> = M.chart(r"t r t

2023-11-27 16:56:18 +0200 answered a question I want to calculate the Riemann tensor and Kretschmann scalar for Kerr- De Sitter spacetime but it is taking too long and not giving any answer please help

The 5-dimensional Kerr-AdS spacetime has been treated there. The Riemann tensor was computed in a reasonable time (it i

2023-11-26 18:48:18 +0200 commented answer How to define a vector field over a chart?

It works for me with SageMath 10.1. Which version of SageMath are you using? What is your operating system?

2023-11-26 16:29:26 +0200 edited answer How to define a vector field over a chart?

You can define a vector field by providing its components in the default frame like this: v = E.vector_field((function(

2023-11-26 16:02:14 +0200 answered a question How to define a vector field over a chart?

You can define a vector field by providing its components in the default frame like this: v = E.vector_field((function(

2023-11-26 15:46:27 +0200 edited question How to define a vector field over a chart?

How to define a vector field over a chart? Hello, I have the following code in sage: E.<x,y,z> = EuclideanSpace()

2023-11-26 15:45:56 +0200 commented answer Wrong result for gradient in spherical coordinates

I have edited my answer to show how to a new vector frame and express the gradient in it.

2023-11-26 15:44:38 +0200 edited answer Wrong result for gradient in spherical coordinates

The answer provided by Sage for the gradient of f is correct: grad(f) = d(F)/dr ∂/∂r + d(F)/dθ/r^2 ∂/∂θ + d(F)/dϕ/(r^2*

2023-11-25 18:00:50 +0200 edited answer Wrong result for gradient in spherical coordinates

The answer provided by Sage for the gradient of f is correct: grad(f) = d(F)/dr ∂/∂r + d(F)/dθ/r^2 ∂/∂θ + d(F)/dϕ/(r^2*

2023-11-25 17:59:34 +0200 answered a question Wrong result for gradient in spherical coordinates

The answer provided by Sage for the gradient of f is correct: grad(f) = d(F)/dr ∂/∂r + d(F)/dθ/r^2 ∂/∂θ + d(F)/dϕ/(r^2*

2023-11-23 14:07:28 +0200 commented answer grad on a generic metric

Actually, parallelism is broken for computations involving symbolic functions (i.e. defined via function as in your case

2023-11-21 14:51:30 +0200 answered a question grad on a generic metric

Your code works for me with SageMath 10.1 (the latest stable version). Which version of SageMath are you using?

2023-11-21 11:22:35 +0200 answered a question [CoCalc][SageManifolds] Error : Black hole rendering with SageMath 3

The notebook Black hole rendering with SageMath works well on my CoCalc account with the SageMath 10.0 kernel (not the 1

2023-11-20 19:20:08 +0200 commented question show(x^2+5) is Showing blank jupyter shell.

It works for me with SageMath 10.1. Which version of SageMath are you using? What is your operating system?