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```#!/usr/bin/env python
#
# a python vector class
# A. Pletzer 5 Jan 00/11 April 2002
#
import math

"""
A list based vector class that supports elementwise mathematical operations

In this version, the vector call inherits from list; this
requires Python 2.2 or later.
"""

class vector(list):
"""
A list based vector class
"""
# no c'tor

def __getslice__(self, i, j):
try:
# use the list __getslice__ method and convert
# result to vector
return vector(super(vector, self).__getslice__(i,j))
except:
raise TypeError, 'vector::FAILURE in __getslice__'

return vector(map(lambda x,y: x+y, self, other))

def __neg__(self):
return vector(map(lambda x: -x, self))

def __sub__(self, other):
return vector(map(lambda x,y: x-y, self, other))

def __mul__(self, other):
"""
Element by element multiplication
"""
try:
return vector(map(lambda x,y: x*y, self,other))
except:
# other is a const
return vector(map(lambda x: x*other, self))

def __rmul__(self, other):
return (self*other)

def __div__(self, other):
"""
Element by element division.
"""
try:
return vector(map(lambda x,y: x/y, self, other))
except:
return vector(map(lambda x: x/other, self))

def __rdiv__(self, other):
"""
The same as __div__
"""
try:
return vector(map(lambda x,y: x/y, other, self))
except:
# other is a const
return vector(map(lambda x: other/x, self))

def size(self): return len(self)

def conjugate(self):
return vector(map(lambda x: x.conjugate(), self))

def ReIm(self):
"""
Return the real and imaginary parts
"""
return [
vector(map(lambda x: x.real, self)),
vector(map(lambda x: x.imag, self)),
]

def AbsArg(self):
"""
Return modulus and phase parts
"""
return [
vector(map(lambda x: abs(x), self)),
vector(map(lambda x: math.atan2(x.imag,x.real), self)),
]

def out(self):
"""
Prints out the vector.
"""
print self

###############################################################################

def isVector(x):
"""
Determines if the argument is a vector class object.
"""
return hasattr(x,'__class__') and x.__class__ is vector

def zeros(n):
"""
Returns a zero vector of length n.
"""
return vector(map(lambda x: 0., range(n)))

def ones(n):
"""
Returns a vector of length n with all ones.
"""
return vector(map(lambda x: 1., range(n)))

def random(n, lmin=0.0, lmax=1.0):
"""
Returns a random vector of length n.
"""
import whrandom
new = vector([])
gen = whrandom.whrandom()
dl = lmax-lmin
return vector(map(lambda x: dl*gen.random(),
range(n)))

def dot(a, b):
"""
dot product of two vectors.
"""
try:
return reduce(lambda x, y: x+y, a*b, 0.)
except:
raise TypeError, 'vector::FAILURE in dot'

def norm(a):
"""
Computes the norm of vector a.
"""
try:
return math.sqrt(abs(dot(a,a)))
except:
raise TypeError, 'vector::FAILURE in norm'

def sum(a):
"""
Returns the sum of the elements of a.
"""
try:
return reduce(lambda x, y: x+y, a, 0)
except:
raise TypeError, 'vector::FAILURE in sum'

# elementwise operations

def log10(a):
"""
log10 of each element of a.
"""
try:
return vector(map(math.log10, a))
except:
raise TypeError, 'vector::FAILURE in log10'

def log(a):
"""
log of each element of a.
"""
try:
return vector(map(math.log, a))
except:
raise TypeError, 'vector::FAILURE in log'

def exp(a):
"""
Elementwise exponential.
"""
try:
return vector(map(math.exp, a))
except:
raise TypeError, 'vector::FAILURE in exp'

def sin(a):
"""
Elementwise sine.
"""
try:
return vector(map(math.sin, a))
except:
raise TypeError, 'vector::FAILURE in sin'

def tan(a):
"""
Elementwise tangent.
"""
try:
return vector(map(math.tan, a))
except:
raise TypeError, 'vector::FAILURE in tan'

def cos(a):
"""
Elementwise cosine.
"""
try:
return vector(map(math.cos, a))
except:
raise TypeError, 'vector::FAILURE in cos'

def asin(a):
"""
Elementwise inverse sine.
"""
try:
return vector(map(math.asin, a))
except:
raise TypeError, 'vector::FAILURE in asin'

def atan(a):
"""
Elementwise inverse tangent.
"""
try:
return vector(map(math.atan, a))
except:
raise TypeError, 'vector::FAILURE in atan'

def acos(a):
"""
Elementwise inverse cosine.
"""
try:
return vector(map(math.acos, a))
except:
raise TypeError, 'vector::FAILURE in acos'

def sqrt(a):
"""
Elementwise sqrt.
"""
try:
return vector(map(math.sqrt, a))
except:
raise TypeError, 'vector::FAILURE in sqrt'

def sinh(a):
"""
Elementwise hyperbolic sine.
"""
try:
return vector(map(math.sinh, a))
except:
raise TypeError, 'vector::FAILURE in sinh'

def tanh(a):
"""
Elementwise hyperbolic tangent.
"""
try:
return vector(map(math.tanh, a))
except:
raise TypeError, 'vector::FAILURE in tanh'

def cosh(a):
"""
Elementwise hyperbolic cosine.
"""
try:
return vector(map(math.cosh, a))
except:
raise TypeError, 'vector::FAILURE in cosh'

def pow(a,b):
"""
Takes the elements of a and raises them to the b-th power
"""
try:
return vector(map(lambda x: x**b, a))
except:
try:
return vector(map(lambda x,y: x**y, a, b))
except:
raise TypeError, 'vector::FAILURE in pow'

def atan2(a,b):
"""
Arc tangent

"""
try:
return vector(map(math.atan2, a, b))
except:
raise TypeError, 'vector::FAILURE in atan2'

###############################################################################
if __name__ == "__main__":

print 'a = zeros(4)'
a = zeros(4)

print 'a.__doc__=',a.__doc__

print 'a[0] = 1.0'
a[0] = 1.0

print 'a[3] = 3.0'
a[3] = 3.0

print 'a[0]=', a[0]
print 'a[1]=', a[1]

print 'len(a)=',len(a)
print 'a.size()=', a.size()

b = vector([1, 2, 3, 4])
print 'a=', a
print 'b=', b

print 'a+b'
c = a + b
c.out()

print '-a'
c = -a
c.out()
a.out()

print 'a-b'
c = a - b
c.out()

print 'a*1.2'
c = a*1.2
c.out()

print '1.2*a'
c = 1.2*a
c.out()
print 'a=', a

print 'dot(a,b) = ', dot(a,b)
print 'dot(b,a) = ', dot(b,a)

print 'a*b'
c = a*b
c.out()

print 'a/1.2'
c = a/1.2
c.out()

print 'a[0:2]'
c = a[0:2]
c.out()

print 'a[2:5] = [9.0, 4.0, 5.0]'
a[2:5] = [9.0, 4.0, 5.0]
a.out()

print 'sqrt(a)=',sqrt(a)
print 'pow(a, 2*ones(len(a)))=',pow(a, 2*ones(len(a)))
print 'pow(a, 2)=',pow(a, 2*ones(len(a)))

print 'ones(10)'
c = ones(10)
c.out()

print 'zeros(10)'
c = zeros(10)
c.out()

print 'del a'
del a

try:
a = random(11, 0., 2.)
a.out()

except: pass
```

History

• revision 3 (21 years ago)
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