idivide

Integer division with rounding option

Syntax

C = idivide(A,B)

C = idivide(A,B,opt)

Description

C = idivide(A,B) divides each element of A by the corresponding element of B, rounded to the nearest integers toward zero. A and B must contain real numbers and at least one of them must belong to an integer class.

• If A and B are arrays, then they must belong to the same integer class and have sizes that are compatible.

• If A or B is a scalar double, then the other input must be an integer class, but not int64 or uint64. The idivide function then returns C as the same integer class.

C = idivide(A,B,opt) specifies an alternative rounding option: 'fix', 'floor', 'ceil', or 'round'. For example, idivide(A,B,'ceil') rounds the quotients to the nearest integers toward positive infinity. The default rounding option is 'fix'.

Examples

Integer Division

Create an integer array A and an integer scalar B. Divide each element of A by B, rounded to the nearest integers toward zero.

A = int16([-7 -4 7 11]);
B = int16(10);
C = idivide(A,B)

C = 1x4 int16 row vector

   0   0   0   1

Divide Two Integer Arrays

Create two integer arrays, A and B. Divide each element of A by the corresponding element of B, rounded to the nearest integers toward zero.

A = int64([-2 3]);
B = int64([3 5]);
C = idivide(A,B)

C = 1x2 int64 row vector

   0   0

Rounding Options for Integer Division

Create a scalar double A and an integer array B. Divide A by each element of B with the default rounding option 'fix'.

A = 2.0;
B = int32([-3 3 4]);
C = idivide(A,B)

C = 1x3 int32 row vector

   0   0   0

Compare the results with other rounding options.

C = idivide(A,B,'floor')

C = 1x3 int32 row vector

   -1    0    0

C = idivide(A,B,'ceil')

C = 1x3 int32 row vector

   0   1   1

C = idivide(A,B,'round')

C = 1x3 int32 row vector

   -1    1    1

Input Arguments

A — Numerator

scalar | vector | matrix | multidimensional array

Numerator, specified as a scalar, vector, matrix, or multidimensional array. Integer inputs A and B must be either the same size or have sizes that are compatible. For example, A is an M-by-N matrix, and B is a scalar or 1-by-N row vector. For more information, see Compatible Array Sizes for Basic Operations.

If A is a scalar double, then B must be an integer class, but not int64 or uint64.

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

B — Denominator

scalar | vector | matrix | multidimensional array

Denominator, specified as a scalar, vector, matrix, or multidimensional array. Integer inputs A and B must be either the same size or have sizes that are compatible. For example, A is an M-by-N matrix, and B is a scalar or 1-by-N row vector. For more information, see Compatible Array Sizes for Basic Operations.

If B is a scalar double, then A must be an integer class, but not int64 or uint64.

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

opt — Rounding option

'fix' (default) | 'floor' | 'ceil' | 'round'

Rounding option, specified as 'fix', 'floor', 'ceil', or 'round'.

• 'fix' rounds to the nearest integers toward zero, which is equivalent to removing any digits after the decimal point.

• 'floor' rounds to the nearest integers toward negative infinity.

• 'ceil' rounds to the nearest integer toward positive infinity.

• 'round' rounds to the nearest integers. If an element has a fractional part of exactly 0.5, then it rounds away from zero to the integer with larger magnitude.

Output Arguments

C — Integer solution

scalar | vector | matrix | multidimensional array

Integer solution, returned as a scalar, vector, matrix, or multidimensional array. If either A or B is an integer data type, then C is the same integer data type.

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

Tips

• The function idivide(A,B,'round') is the same as A./B and B.\A for integer data types. The argument opt provides the rounding options for A./B and B.\A when dividing integers.

• MATLAB^® does not support complex integer division.

Extended Capabilities

Tall Arrays

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

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

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• For efficient generated code, MATLAB rules for divide by zero are supported only for the 'round' option.

• Code generation does not support sparse matrix inputs for this function.

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 idivide 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 in R2006a