isinf

Determine which array elements are infinite

Syntax

TF = isinf(A)

Description

TF = isinf(A) returns a logical array containing 1 (true) where the elements of the array A are Inf or -Inf, and 0 (false) where they are not. If A contains complex numbers, isinf(A) contains 1 for elements with infinite real or imaginary part, and 0 for elements where both real and imaginary parts are finite or NaN.

Examples

Determine Infinite Real Elements

Create a row vector and determine the infinite elements.

A = 1./[-2 -1 0 1 2]

A = 1×5

   -0.5000   -1.0000       Inf    1.0000    0.5000

TF = isinf(A)

TF = 1x5 logical array

   0   0   1   0   0

Determine Infinite Complex Elements

Create an array of complex numbers. Determine whether the complex numbers contain infinite values.

A = [2 + 1i, 3 + 1i/0, 0/0 - 2i]

A = 1×3 complex

   2.0000 + 1.0000i   3.0000 +    Infi      NaN - 2.0000i

TF = isinf(A)

TF = 1x3 logical array

   0   1   0

The second element of A has an infinite imaginary part. For this element, isinf returns 1.

Input Arguments

A — Input array

scalar | vector | matrix | multidimensional array

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

Tips

• If x is a real scalar, exactly one of isfinite(x), isinf(x), and isnan(x) returns logical 1 (true).

• For a complex scalar z, isinf(z) and isnan(z) can both return logical 1. For example, isinf(complex(Inf,NaN)) and isnan(complex(Inf,NaN)) both return logical 1.

Extended Capabilities

Tall Arrays

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

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

C/C++ Code Generation
Generate C and C++ code using MATLAB® 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 isinf 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