分类：物理学

GRTensor 下载地址：https://github.com/grtensor/grtensor

GRTensor 博客：https://hyperspace.uni-frankfurt.de/2016/12/07/grtensoriii-for-maple-has-been-released/

GRTensor wiki介绍：https://github.com/grtensor/grtensor/wiki

GRTensor 官方网站：http://grtensor.phy.queensu.ca/

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本段摘选自GRTensor wiki介绍，链接在上面已经给出。

GRTensorIII is provided as Maple package in the  lib/  directory of the project. This lib directory needs to be included in your Maple library path.

This can be accomplished in a Maple session with a command like (changing the path to the directory on your system):

For Windows users (DOUBLE backslashes!!):

If the library is not found the cryptic error message will say something like: “with expects it’s first argument to be of type….”

Alternately, this command can be placed in the Maple init file in the home directory on your computer. See Maple Init File

GRIII can then be loaded via:

And the output will be:

It is then useful to ensure you have a suitable path set for loading and saving metrics. This is controlled by the global variable  grOptionMetricPath . The current option settings are displayed with the command  groptions(); . The grtensor distribution includes a directory with some useful metrics in  metrics/ .

grOptionMetricPath can be configured by assignment in the Maple session or set in your  .mapleinit  file.

GRTensorIII contains a new option variable  grOptionMapletInput  (default  true ). More recent Maple releases have made dialog box input the default mode. The interactive routines in GRTensorIII now use these dialogs by default. If this is not desired, set this option variable to  false . See  ?groptions for a description of all the options for GRTensorIII.

Getting Started

There are multiple approaches to get started with GRTensor:

• consult the built in help.  ?grtensor  and  ?grt_commands  are a good starting point
• open one of the sample worksheets in the  worksheets  directory
• read the PDF docs, typically starting with  grIntro.pdf  in the  docs/  directory.