[Scilab-users] {EXT} Re: [EXTERNAL] Re: acos leads to complex values

[Dang Ngoc Chan, Christophe]

Hello,



> De : Federico Miyara

> Envoyé : mardi 29 janvier 2019 21:36

>

> This is an improved version of the acos function with input argument check:



I would personally write it in the following way:


function y=acos1(x)
    // Check if components are real
    // Check if components are real and belong to [-1, 1]
    absx = abs(x);
    in_domain = (imag(x)==0) & (-1<=absx) & (absx<=1);
    // Imaginary part of acos(x) is accepted only if
    // x does not belong to [-1, 1]
    y=acos(x);
    y(in_domain) = real(y(in_domain));
endfunction



Regards



--

Christophe Dang Ngoc Chan

Mechanical calculation engineer




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