Defining a matrix in Magma with finite field entries Consider the following matrix 
$$
 G:=\left[ 
\begin {array}{cccccccc} 
1&0&0&0&\alpha&\alpha+1&1&1\\ 
0&1&0&0&1&\alpha&\alpha+1&1\\
 0&0&1&0&1&1&\alpha&\alpha+1\\ 
0&0&0&1&\alpha+1&1&1&
\alpha\end {array} 
\right]
$$
where entries of matrix $G$ come from finite field $GF(2^8)$ such that this finite field is constructed by the polynomial ${\alpha}^{8}+{\alpha}^{4}+{\alpha}^{3}+\alpha+1$. 
My question: How to define matrix $G$ in the MAGMA software such that we can see the coding parameters  that are generated with the matrix $G$? 

At First, we should define the finite field $GF(2^8)$ by our polynomial as follows
$$
K<x>:=ExtensionField< GF(2), z | z^8+z^4+z^3+z+1 >;
$$
After that we have to define matrix space over the finite field $K$, in the following form 
$$
M := KMatrixSpace(K, 4, 8);
$$
Now, we define our matrix as shown
$$
G := M ! [1,0,0,0,x,x+1,1,1,0,1,0,0,1,x,x+1,1,0,0,1,0,1,1,x,x+1,0,0,0,1,x+1,1,1,x];
$$
In continue, we find coding parametr of $G$, by this command
$$
C := LinearCode(G);
$$
I asked two questions about math software in the Math stack. The first question was about Maple that no one answer and because of this I asked from support team of Maple. The next question that you can see was about Magma that again no one answer and I read two chapters of Magma guide to find it's method. 
I strongly believed that Math software tags of math stack should be independent of math stack and it's better that defined a separate forum for this special tags.  
