### Create a band matrix with repeating and alternating values

I have 7 values: a, b, c, d, e, f and g

I would like to construct an m by n matrix in this way:

```
[ a b c d 0 0 0 0 . . . .]
[ b e f g 0 0 0 0 . . . .]
[ c f a b c d 0 0 . . . .]
[ d g b e f g 0 0 . . . .]
[ 0 0 c f a b c d 0 0 . .]
[ 0 0 d g b e f g 0 0 . .]
[ . . 0 0 c f a b c d . .]
[ . . 0 0 d g b e f g . .]
```

And so forth...

Therefore, the desired matrix is symmetrical. Values **a** and **e** alternate on the main diagonal; values **b** and **f** alternate on the *1st upper diagonal*; values **c** and **g** alternate on the *2nd upper diagonal*; values **d** and **0** alternate on the *3rd upper diagonal*. I would like to be able to specify the matrix size with m by n parameters (even though the resulting matrix is non-square).

What would be an efficient way to construct this matrix?