ATAN2D(Y, X) computes the principal value of the argument function of the complex number X + i Y in degrees. This function can be used to transform from Cartesian into polar coordinates and allows to determine the angle in the correct quadrant.
Fortran 2023
Elemental function
RESULT = ATAN2D(Y, X)
| Y | The type shall be REAL. |
| X | The type and kind type parameter shall be the same as Y. If Y is zero, then X must be nonzero. |
The return value has the same type and kind type parameter as Y. It is the principal value of the complex number X + i Y. If X is nonzero, then it lies in the range -180 \le \atan (x) \leq 180. The sign is positive if Y is positive. If Y is zero, then the return value is zero if X is strictly positive, 180 if X is negative and Y is positive zero (or the processor does not handle signed zeros), and -180 if X is negative and Y is negative zero. Finally, if X is zero, then the magnitude of the result is 90.
program test_atan2d real(4) :: x = 1.e0_4, y = 0.5e0_4 x = atan2d(y,x) end program test_atan2d
| Name | Argument | Return type | Standard |
|---|---|---|---|
ATAN2D(X, Y) |
REAL(4) X, Y |
REAL(4) |
Fortran 2023 |
DATAN2D(X, Y) |
REAL(8) X, Y |
REAL(8) |
GNU extension |
Alias: ATAND — Arctangent function, degrees Radians function: ATAN2 — Arctangent function
© Free Software Foundation
Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gfortran/ATAN2D.html