By default hist uses 10 bins to create a histogram. You can change the resolution either by specifying the number of bins or the bin centres. For example, to make a histogram with 100 bins:
[p,x] = hist(sample1,100);
Alternatively, you can specify the bin centres instead of number of bins.
bincntr = 10:10:2000
[p,x] = hist(sample1,bincntr);
In the second case, x will be equal to bincntr