Lagrange¶
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class
dolfin.cpp.function.
Lagrange
(*args)¶ Bases:
dolfin.cpp.common.Variable
Lagrange
polynomial (basis) with given degree q determined by n = q + 1 nodal points. Example: q = 1 (n = 2)Lagrange
p(1); p.set(0, 0.0); p.set(1, 1.0); It is the callers responsibility that the points are distinct. This creates aLagrange
polynomial (actually twoLagrange
polynomials): p(0,x) = 1 - x (one at x = 0, zero at x = 1) p(1,x) = x (zero at x = 0, one at x = 1)Copy constructor.
Parameters: Lagrange & p (const) – -
ddx
()¶ Return derivate of polynomial i at given point x
Parameters: - i (std::size_t) – (std::size_t)
- x (double) – (double)
Return type: double
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degree
()¶ Return degree
Return type: std::size_t Returns: std::size_t
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dqdx
()¶ Return derivative q (a constant) of polynomial
Parameters: i (std::size_t) – (std::size_t) Return type: double
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eval
()¶ Return value of polynomial i at given point x
Parameters: - i (std::size_t) – (std::size_t)
- x (double) – (double)
Return type: double
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point
()¶ Return point
Parameters: i (std::size_t) – (std::size_t) Return type: double
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set
()¶ Specify point
Parameters: - i (std::size_t) – (std::size_t)
- x (double) – (double)
Return type: void
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size
()¶ Return number of points
Return type: std::size_t Returns: std::size_t
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thisown
¶ The membership flag
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