expansion.rweight.ipynb

Kernel: Python 3

expansion.rweight(weight)

The right scalar product of an expansion by a weight.

See also:

• expression.rweight

• expansion.lweight

Examples

import vcsn
c = vcsn.context('lal_char, q')

Note that left-scalar product and right-scalar product are very different: the left-scalar product changes the weights in the polynomials, while the right-scalar product changes the expressions.

e = c.expression('<2>a<3>bc', 'none')
x = e.expansion()
e

$\left\langle 2 \right\rangle \,a \, \left( \left\langle 3 \right\rangle \,b \, c\right)$

x.rweight(c.weight('4'))

$a \odot \left[\left\langle 2\right\rangle \left(\varepsilon \, \left( \left\langle 3 \right\rangle \,b \, c\right)\right)\, \left\langle 4 \right\rangle \right]$

Instead of x.rweight(w), you may write x * w.

x * c.weight('4')

$a \odot \left[\left\langle 2\right\rangle \left(\varepsilon \, \left( \left\langle 3 \right\rangle \,b \, c\right)\right)\, \left\langle 4 \right\rangle \right]$

You may even run the simpler:

x * 4

$a \odot \left[\left\langle 2\right\rangle \left(\varepsilon \, \left( \left\langle 3 \right\rangle \,b \, c\right)\right)\, \left\langle 4 \right\rangle \right]$

The expansion of a scalar product is the scalar product of the expansion:

(e*4).expansion()

$a \odot \left[\left\langle 2\right\rangle \left(\varepsilon \, \left( \left\langle 3 \right\rangle \,b \, c\right)\right)\, \left\langle 4 \right\rangle \right]$