I want to initialize an empty list and keep on adding new rows to it. For example.
myarray=[]
now at each iteration I want to add new row which I compute during iteration. For example

```
for i in range(5):
     calc=[i,i+1,i+4,i+5]

```

After calc I want to add this row to myarray. Therfore after 1st iteration myarray would be 1X4, after 2nd iteration it would be 2X4 etc. I tried numpy.concatenate. It simply adds to same row ie I get 1X4 then 1X8. I tried vstack as well but since myarray is initially [] it gives error "all the input array dimensions except for the concatenation axis must match exactly"