graduate — pretty axis graduations
[xi,xa,np]=graduate( xmi, xma,n1,n2) [xi,xa,np]=graduate( xmi, xma)
graduate looks for the minimum interval [xi,xa]
and a number of tics
np
such that:
xi <= xmi <= xma <= xa
xa - xi / np = k(10^n)
,k
in [1 3 5]
for an integer n
n1 < np < n2