Dense
Dense, immutable vector operations.
>>> from vector import vecadd
>>> a = (5, 6, 7)
>>> b = [2]
>>> c = range(4)
>>> vecadd(a, b, c)
(7, 7, 9, 3)
Prefixed by vec... (vector).
All functions accept vectors as single exhaustible iterables.
They return vectors as tuples.
The functions are type-independent. However, the coefficients used must support necessary scalar operations. For instance, for vector addition, coefficients must be addable.
For complete type safety a zero argument is available. Default is int(0).
Docstring conventions
Summary
Math notation (vector notation if possible, index notation, domain & codomain)
More information ("More efficient than ...").
Complexity
For a vector of length \(n\) there will be - \(x\) scalar additions (add), ...
Notes
Design choices
See also
Similar functions
References
Wikipedia, numpy, ...
creation
veczero = ()
Zero vector.
An empty tuple: ().
vecbasis(i, c=1, zero=0)
Return a basis vector.
Returns a tuple with i many zeros followed by c.
See also
- for all basis vectors:
vecbases
Source code in vector\dense\creation.py
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vecbases(start=0, c=1, zero=0)
Yield all basis vectors.
See also
- for single basis vector:
vecbasis
Source code in vector\dense\creation.py
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vecrand(n)
Return a random vector of uniform sampled float coefficients.
The coefficients are sampled from a uniform distribution in [0, 1[.
Notes
Naming like numpy.random,
because seems more concise (not random & gauss as in the stdlib).
Source code in vector\dense\creation.py
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vecrandn(n, normed=True, mu=0, sigma=1, weights=None)
Return a random vector of normal sampled float coefficients.
The coefficients are sampled from a normal distribution.
Notes
Naming like numpy.random,
because seems more concise (not random & gauss as in the stdlib).
Source code in vector\dense\creation.py
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utility
veclen(v)
Return the length (number of set coefficients).
Doesn't handle trailing zeros, use vectrim
if needed.
Notes
For generators as they have no length, altough the vector is gone then.
Source code in vector\dense\utility.py
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veceq(v, w)
Return whether two vectors are equal.
Complexity
For two vectors of lengths \(n\) & \(m\) there will be at most
- \(\min\{n, m\}\) scalar comparisons (
eq) & - \(|n-m|\) scalar boolean evaluations (
bool).
Source code in vector\dense\utility.py
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vectrim(v, tol=None)
Remove all trailing near zero (abs(v_i)<=tol) coefficients.
tol may also be None,
then all coefficients that evaluate to False are trimmed.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar absolute evaluations (
abs) & - \(n\) scalar comparisons (
gt).
Notes
- Cutting of elements that are
abs(v_i)<=tolinstead ofabs(v_i)<tolto allow cutting of elements that are exactly zero bytrim(v, 0)instead oftrim(v, sys.float_info.min).
Source code in vector\dense\utility.py
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vecrshift(v, n, zero=0)
Shift coefficients up.
Source code in vector\dense\utility.py
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veclshift(v, n)
Shift coefficients down.
Source code in vector\dense\utility.py
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hilbert_space
vecconj(v)
Return the complex conjugate.
Tries to call a method conjugate on each element.
If not found, simply keeps the element as is.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar conjugations (
conjugate).
Source code in vector\dense\hilbert_space.py
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vecabs(v, weights=None, conjugate=False, zero=0)
Return the Euclidean/\(\ell_{\mathbb{N}_0}^2\)-norm.
Returns the square root of vecabsq.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar conjugations (
conjugate) (if selected), - \(n\)/\(2n\) scalar multiplications (
mul) without/with weights, - \(\begin{cases}n-1&n\ge1\\0&n\le1\end{cases}\) scalar additions (
add) & - one
^0.5call.
See also
- squared version without square root:
vecabsq
Source code in vector\dense\hilbert_space.py
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vecabsq(v, weights=None, conjugate=False, zero=0)
Return the sum of absolute squares.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar conjugations (
conjugate) (if selected), - \(\begin{cases}n-1&n\ge1\\0&n\le1\end{cases}\) scalar additions (
add) & - \(n\)/\(2n\) scalar multiplications (
mul) without/with weights.
Notes
Reasons why it exists:
- Occurs in math.
- Most importantly: type independent because it doesn't use
sqrt.
References
Source code in vector\dense\hilbert_space.py
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vecdot(v, w, weights=None, conjugate=False, zero=0)
Return the inner product.
Complexity
For two vectors of lengths \(n\) & \(m\) there will be
- \(\min\{n, m\}\) scalar conjugations (
conjugate) (if selected), - \(\min\{n, m\}\)/\(2\min\{n, m\}\) scalar multiplications (
mulwithout/with weights) & - \(\begin{cases}\min\{n, m\}-1&n\ge1\land m\ge1\\0&n\le1\lor m\le1\end{cases}\) scalar additions (
add).
Source code in vector\dense\hilbert_space.py
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vector_space
vecpos(v)
Return the identity.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar unary plus operations (
pos).
Source code in vector\dense\vector_space.py
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vecneg(v)
Return the negation.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar negations (
neg).
Source code in vector\dense\vector_space.py
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vecadd(*vs)
Return the sum.
Complexity
For two vectors of lengths \(n\) & \(m\) there will be
- \(\min\{n, m\}\) scalar additions (
add).
See also
- for sum on a single coefficient:
vecaddc
Source code in vector\dense\vector_space.py
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vecaddc(v, c, i=0, zero=0)
Return the sum with a basis vector.
More efficient than vecadd(v, vecbasis(i, c)).
Complexity
There will be
- one scalar addition (
add) if \(i\le n\) or - one unary plus operations (
pos) otherwise.
See also
- for sum on more coefficients:
vecadd
Source code in vector\dense\vector_space.py
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vecsub(v, w)
Return the difference.
Complexity
For two vectors of lengths \(n\) & \(m\) there will be
- \(\min\{n, m\}\) scalar subtractions (
sub) & - \(\begin{cases}m-n&m\ge n\\0&m\le n\end{cases}\) negations (
neg).
See also
- for difference on a single coefficient:
vecsubc
Source code in vector\dense\vector_space.py
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vecsubc(v, c, i=0, zero=0)
Return the difference with a basis vector.
More efficient than vecsub(v, vecbasis(i, c)).
Complexity
There will be
- one scalar subtraction (
sub) if \(i\le n\) or - one scalar negation (
neg) otherwise.
See also
- for difference on more coefficients:
vecsub
Source code in vector\dense\vector_space.py
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vecmul(v, a)
Return the product.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar multiplications (
rmul).
Source code in vector\dense\vector_space.py
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vecrmul(a, v)
Return the product.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar multiplications (
rmul).
Source code in vector\dense\vector_space.py
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vectruediv(v, a)
Return the true quotient.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar true divisions (
truediv).
Notes
Why called truediv instead of div?
divwould be more appropriate for an absolute clean mathematical implementation, that doesn't care about the language used. But the package might be used for pure integers/integer arithmetic, so both,truedivandfloordivoperations have to be provided, and none should be privileged over the other by getting the universaldivname.truediv/floordivis unambiguous, like Pythonoperators.
Source code in vector\dense\vector_space.py
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vecfloordiv(v, a)
Return the floor quotient.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar floor divisions (
floordiv).
Source code in vector\dense\vector_space.py
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vecmod(v, a)
Return the remainder.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar modulos (
mod).
Source code in vector\dense\vector_space.py
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vecdivmod(v, a)
Return the floor quotient and remainder.
Complexity
For a vector of length \(n\) there will be
- \(n\) scalar divmods (
divmod).
Source code in vector\dense\vector_space.py
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elementwise
vechadamard(*vs)
Return the elementwise product.
Complexity
For vectors of lengths \(n_1, n_2, \dots, n_N\) there will be
- \(\begin{cases}(N-1)\min_in_i&N\ge1\land\min_in_i\ge1\\0&N\le1\lor\min_in_i=0\end{cases}\) scalar multiplications (
mul).
Source code in vector\dense\elementwise.py
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vechadamardtruediv(v, w)
Return the elementwise true quotient.
Complexity
For two vectors of lengths \(n\) & \(m\) there will be
- \(n\) scalar true divisions (
truediv).
Source code in vector\dense\elementwise.py
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vechadamardfloordiv(v, w)
Return the elementwise floor quotient.
Complexity
For two vectors of lengths \(n\) & \(m\) there will be
- \(n\) scalar floor divisions (
floordiv).
Source code in vector\dense\elementwise.py
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vechadamardmod(v, w)
Return the elementwise remainder.
Complexity
For two vectors of lengths \(n\) & \(m\) there will be
- \(n\) scalar modulos (
mod).
Source code in vector\dense\elementwise.py
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vechadamarddivmod(v, w)
Return the elementwise floor quotient and remainder.
Complexity
For two vectors of lengths \(n\) & \(m\) there will be
- \(n\) scalar divmods (
divmod).
Source code in vector\dense\elementwise.py
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vechadamardmin(*vs, key=None)
Return the elementwise minimum.
Complexity
For two vectors of lengths \(n\) & \(m\) there will be
- \(\min\{n, m\}\) comparisons (
lt).
Source code in vector\dense\elementwise.py
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vechadamardmax(*vs, key=None)
Return the elementwise maximum.
Complexity
For two vectors of lengths \(n\) & \(m\) there will be
- \(\min\{n, m\}\) comparisons (
gt).
Source code in vector\dense\elementwise.py
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