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Inverse tangent in radians



Y = atan(X) returns the Inverse Tangent (tan-1) of the elements of X in radians. The function accepts both real and complex inputs.

  • For real values of X, atan(X) returns values in the interval [-π/2, π/2].

  • For complex values of X, atan(X) returns complex values.


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Find the inverse tangent of a value.

ans = 0.6747

Find the inverse tangent of the elements of vector x. The atan function acts on x element-wise.

x = [0.5i 1+3i -2.2+i];
Y = atan(x)
Y = 1×3 complex

   0.0000 + 0.5493i   1.4615 + 0.3059i  -1.2019 + 0.1506i

Plot the inverse tangent function over the interval -20x20.

x = -20:0.01:20; 
grid on

Input Arguments

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Tangent of angle, specified as a scalar, vector, matrix, multidimensional array, table, or timetable. The atan operation is element-wise when X is nonscalar.

Data Types: single | double | table | timetable
Complex Number Support: Yes

More About

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Inverse Tangent

The inverse tangent is defined as


This definition of the atan function returns angles in radians within the interval [-π/2, π/2]. To find the four-quadrant inverse tangent, where the returned angles are in the interval [-π, π], use atan2.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Version History

Introduced before R2006a

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See Also

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