## logt

Logarithm by tau approximation for itau object.

Logarithm by tau approximation for itau object.

[F, e, n] = logt(x)

F = logt(x) is a function to approximate by tau method log(x), x in [a, b]. This function goal is to take the machine precision in this approximation, once logt(x) can be a funcional coeefficient at the equation. For this porpouse, we are ulogg schursolver function, which will decide the approximation degree to achieve 1e-16. Concluding, now is possible to use logt(x) as coefficient.

x = independent tau variable (itau object).

F = polynomial approximation of log(x) in [a, b] evaluated (with orthovalM) in argument M = matrixM(x) (double matrix).

sint, sinht, cost, cosht, and expt.