def testDiv(self):
""" test division """
a = Table(['a','b','c','d'],[2,3,4,5],range(2*3*4*5))
b = Table(['c','b','e'],[4,3,6],range(12*6))
c = Table(['a','b','c','d','e'],[2,3,4,5,6],range(2*3*4*5*6))
acpt = copy(a.cpt)[...,na.NewAxis]
bcpt = copy(b.cpt)[...,na.NewAxis,na.NewAxis]
bcpt.transpose([3,1,0,4,2])
ab = a/b
cc = c/c
bb = b/b
cres = na.ones(2*3*4*5*6)
cres[0] = 0
bres = na.ones(12*6)
bres[0] = 0
ares = acpt/bcpt
ares[getnan(ares)] = 0.0
assert (ab == Table(['a','b','c','d','e'],[2,3,4,5,6],ares) and \
cc == Table(['a','b','c','d','e'],[2,3,4,5,6],cres) and \
bb == Table(['c','b','e'],[4,3,6],bres) ), \
" Division does not work"
def evaluate(c, y, x):
"Evaluates c in the context of _UFuncs, x, and y."
x,y = (x - SIZE/2) * RATIO, (SIZE/2 - y) * RATIO
# Misalign some math errors
x += 1e-10
y += 1e-10
result = eval(c, ufunc._UFuncs, dict(x=x,y=y))
try:
len(result)
except TypeError:
# Idiot c evaluated to a float. This is because the random tree
# generator picked all constants, without any x or y. Let's be
# nice and turn it into a bunch of that result.
result *= ones(type=Float64, shape=(SIZE, SIZE))
# Normalize the data to interval[0,255]. Do this by finding the
# minimum and maximum values.
copy = ravel(result.copy())
copy.sort()
for minv in copy:
if not is_special(minv): break
else: raise ValueError("Ack! No numbers!")
for maxv in copy[::-1]:
if not is_special(maxv): break
else: break
else: raise ValueError("Ack! No numbers!")
print "Min, max:", (minv,maxv)
diff = maxv-minv+1
result[ieee.getnan(result)] = minv
result[ieee.getneginf(result)] = minv
result[ieee.getposinf(result)] = maxv
result -= minv
result /= diff
result *= 255
result[ieee.getnan(result)] = 0
result[ieee.getinf(result)] = 0
return result.astype(UInt32)
def testIDiv(self):
""" test inplace division """
b = Table(['c','b','e'],[4,3,6],range(12*6))
c = Table(['a','b','c','d','e'],[2,3,4,5,6],range(2*3*4*5*6))
bcpt = b.cpt[...,na.NewAxis,na.NewAxis]
bcpt.transpose([3,1,0,4,2])
res = c.cpt/bcpt
res[getnan(res)] = 0.0
c /= b
assert (na.all(c.cpt == res)), \
" InPlace Division does not work"
def __div__(a, b):
"""
multiplication
PRE:
a=Pr(A); A = {'a','b','c'}
b=Pr(B); B = {'c','a','d','e'}
usage:
c = a/b
c is a NEW Table instance
POST:
c=Pr(A U B) = Pr(a,b,c,d,e)
Notes :
- c keeps the order of the variables in a
- any new variables in b (d and e) are added at the end of c in the
order they appear in b
- a and b are not touched during this operation
- return a NEW Table instance
"""
#########################################
#---TODO: add division with a number
#########################################
# prepare dimensions in a and b for multiplication
new, cptb = a.union(b)
# multiply
#new.cpt /= cptb # this does not work correctly for some reason...
#na.divide(new.cpt,cptb,new.cpt) # does not work either
new.cpt = new.cpt / cptb #this one works fine
#is this a numarray BUG????
## WARNING, division by zero, avoided using na.Error.setMode(invalid='ignore')
# replace INFs by 0s
new.cpt[getnan(new.cpt)] = 0
#---TODO: replace this very SLOW function with a ufunc
return new
def __idiv__(a,b):
"""
in place division
PRE:
- B must be a subset of A!!!
eg.
a=Pr(A); A = {'a','b','c'}
b=Pr(B); B = {'c','a'}
usage:
a/=b
POST:
a=Pr(A)/Pr(B) = Pr(a,b,c)
Notes :
- a keeps the order of its existing variables
- b is not touched during this operation
- operation is done in-place for a, a is not the same after the operation
"""
# prepare dimensions in b for multiplication
cptb = a.prepareOther(b)
# multiply in place, a's values are changed
#a.cpt /= cptb # this does not work correctly for some reason...
#na.divide(a.cpt,cptb,a.cpt) # does not work either
a.cpt = a.cpt / cptb #this one works fine
#is this a numarray BUG????
## WARNING, division by zero, avoided using na.Error.setMode(invalid='ignore')
# replace INFs by 0s
a.cpt[getnan(a.cpt)] = 0
#---TODO: replace this very SLOW function with a ufunc
return a
