@Markiyan Hirnyk 

more references

https://en.m.wikipedia.org/wiki/Geodesic

regards

Eli

@Markiyan Hirnyk 

Some reference

https://en.m.wikipedia.org/wiki/Minkowski_space

Regard

Eli

@Markiyan Hirny 

minkowski space is 4 dimensional Space.

The equation of Motion arme The geodetic line, you can calculate the equations with the metric and the chistofel symbols, but I am using different approach. Of course the result are the same.

I hope I could answer your quastion?

@John Fredsted 

o.k this is what I need perfect!

G:=get_compts(Estn)

for Einstein Tensor

thank you

@panke 

again, G is not the metric (input)! G is the output !

@tomleslie 

o.k

the results are table ,so how can I  can convert it to array? (Matrix) ?.

Thus is what I need

for example G is a 4x4 Matrix

@tomleslie 

o.k.

what i meant is:

Everything works perfect.

The result that I get is file list.

I need it into array, let say G[4,4] for the result of Einstein field.

The program doesn't provide it?