complex

Create complex array

Syntax

z = complex(a,b)

z = complex(x)

Description

z = complex(a,b) creates a complex output, z, from two real inputs, such that z = a + bi.

The complex function provides a useful substitute for expressions, such as a + 1i*b or a + 1j*b, when

• a and b are not double or single

• b is all zeros

z = complex(x) returns the complex equivalent of x, such that isreal(z) returns logical 0 (false).

• If x is real, then z is x + 0i.

• If x is complex, then z is identical to x.

Examples

Complex Scalar from Two Real Scalars

Use the complex function to create the complex scalar, 3 + 4i.

z = complex(3,4)

z = 
3.0000 + 4.0000i

Complex Vector from Two Real Vectors

Create a complex uint8 vector from two real uint8 vectors. The size of z, 4-by-1, is the same as the size of the input arguments.

a = uint8([1;2;3;4]);
b = uint8([2;2;7;7]);

z = complex(a,b)

z = 4×1 uint8 column vector

   1 +   2i
   2 +   2i
   3 +   7i
   4 +   7i

Complex Scalar from One Real Scalar

Create a complex scalar with zero imaginary part.

z = complex(12)

z = 
12.0000 + 0.0000i

Verify that z is complex.

isreal(z)

ans = logical
   0

Input Arguments

a — Real component

scalar | vector | matrix | multidimensional array

Real component, specified as a scalar, vector, matrix, or multidimensional array.

The size of a must match the size of b, unless one is a scalar. If either a or b is a scalar, MATLAB^® expands the scalar to match the size of the other input.

a and b can have different data types. However, if either a or b is an integer data type, then the other input must have the same integer type or be a full (not sparse) scalar double.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical

b — Imaginary component

scalar | vector | matrix | multidimensional array

Imaginary component, specified as a scalar, vector, matrix, or multidimensional array.

The size of b must match the size of a, unless one is a scalar. If either a or b is a scalar, MATLAB expands the scalar to match the size of the other input.

a and b can have different data types. However, if either a or b is an integer data type, then the other input must have the same integer type or be a full (not sparse) scalar double.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical

x — Input array

scalar | vector | matrix | multidimensional array

Input array, specified as a scalar, vector, matrix, or multidimensional array.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical
Complex Number Support: Yes

Output Arguments

z — Complex array

scalar | vector | matrix | multidimensional array

Complex array, returned as a scalar, vector, matrix, or multidimensional array.

The size of z is the same as the input arguments.

The following describes the data type of z when a and b have different data types.

• If either a or b is single, then z is single.

• If either a or b is logical, then z is the data type of the nonlogical input.

• If either a or b is an integer data type, then z is the same integer data type.

Additionally, z is only sparse when both input arguments a and b are sparse.

Tips

• If b contains only zeros, then z is complex and the value of all its imaginary components is 0. In contrast, the addition a + 0i returns a strictly real result.

Extended Capabilities

Tall Arrays

Calculate with arrays that have more rows than fit in memory.

The complex function fully supports tall arrays. For more information, see Tall Arrays.

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

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

HDL Code Generation
Generate VHDL, Verilog and SystemVerilog code for FPGA and ASIC designs using HDL Coder™.

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

The complex function fully supports GPU arrays. To run the function on a GPU, specify the input data as a gpuArray (Parallel Computing Toolbox). For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).

Distributed Arrays

Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.

This function fully supports distributed arrays. For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).

Version History

Introduced before R2006a