mtlb_legendre Matlab legendre emulation function

## Syntax

    P = mtlb_legendre(n,X)
                P = mtlb_legendre(n,X[,normflag])

## Arguments

X

  a scalar, vector, matrix or hypermatrix with elements in [-1,1]

n

  a positive scalar integer

normflag

  a string ('sch' or 'norm')

## Description

Matlab and Scilab `legendre` behave differently in some particular cases:

- Scilab `legendre(m,n,X)` evaluates the `legendre` function of degree n and order n for the `X` elements. Matlab `legendre(n,X)` evaluates the Legendre functions of degree `n` and order `m`=0,1,...,n. (emulated by mtlb_legendre) for the `X` elements.

- The option normflag= `'sch'` does not exist for Scilab legendre (emulated)

- If `X` is a hypermatrix then Scilab `legendre(n,X)` does not work (emulated)

The function `mtlb_legendre(n,X[,normflag])` is used by `mfile2sci` to replace `legendre(n,X[,normflag])` when it was not possible to know what were the inputs while porting Matlab code to Scilab. This function will determine the correct semantic at run time. If you want to have a more efficient code it is possible to replace `mtlb_legendre` call:

- If `X` is a scalar, a vector or a matrix `mtlb_legendre(n,X[,'norm'])` may be replaced by `legendre(n,0:n,X[,'norm'])`

Caution: `mtlb_legendre` has not to be used for hand coded functions.