ENH: Enhanced the problem set building on the image handing and arrays.
Illustrated dtypes, casting and their importance along with an example
using RGBA images. Also introduce edge detection.
d1 = [2,4,6,8]
d0 = [0,2,4,6,8]
dq = [0, 4, 6]
for a in d1:
th = a * 1000
for b in d0:
hu = b * 100
for c in d0:
te = c * 10
for u in dq:
n = th + hu + te + u
if is_square(n): print n
for i in range(46, 94, 2):
n = i * i
if all_even( n ): print n