angle of a vector

[compsystems]

Hi, the command ARG() says

Angle of a vector
The arg command finds the angle of a complex number (the argument) or the angle of a vector defined by two points.

arg takes v, a number or a vector defined by two points.
arg(v) returns the argument of v if v is a complex number or the angle between the positive x direction and v if v is a vector.
Example
arg(1+i) -> pi/4


How do you get the angle of a vector?

I wish to obtain
arg([3,4]) -> atan(4/3)

[parisse]

I'm afraid you are confused, arg does not take a vector or 2 points as argument, it expects a complex number.

[XcasEngGuy]

Try this:

test.jpg (28.78 Kio) Consulté 1133 fois

[compsystems]

Hello
Please expand the functionality to accept a vector.

[XcasEngGuy]

Try:

Code : Tout sélectionner

vec_arg(vec):={
  var cmplx;
  cmplx:=vec[0]+i*vec[1];
  return evalf(arg(cmplx));
}:;