lt, <

Determine less than

Syntax

A < B

lt(A,B)

Description

A < B returns an array with elements set to logical 1 (true) where A is less than B; otherwise, the element is logical 0 (false). The test compares only the real part of numeric arrays. lt returns logical 0 (false) where A or B have NaN or undefined categorical elements.

lt(A,B) is an alternate way to execute A < B, but is rarely used. It enables operator overloading for classes.

Examples

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Test Vector Elements

Open Live Script

Determine if vector elements are less than a given value.

Create a numeric vector.

A = [1 12 18 7 9 11 2 15];

Test the vector for elements that are less than 12.

A < 12

ans = 1x8 logical array

   1   0   0   1   1   1   1   0

The result is a vector with values of logical 1 (true) where the elements of A satisfy the expression.

Use the vector of logical values as an index to view the values in A that are less than 12.

A(A < 12)

ans = 1×5

     1     7     9    11     2

The result is a subset of the elements in A.

Replace Elements of Matrix

Open Live Script

Create a matrix.

A = magic(4)

A = 4×4

    16     2     3    13
     5    11    10     8
     9     7     6    12
     4    14    15     1

Replace all values less than 9 with the value 10.

A(A < 9) = 10

A = 4×4

    16    10    10    13
    10    11    10    10
     9    10    10    12
    10    14    15    10

The result is a new matrix whose smallest element is 9.

Compare Values in Categorical Array

Open Live Script

Create an ordinal categorical array.

A = categorical({'large' 'medium' 'small'; 'medium' ...
'small' 'large'},{'small' 'medium' 'large'},'Ordinal',1)

A = 2x3 categorical
     large       medium      small 
     medium      small       large

The array has three categories: 'small', 'medium', and 'large'.

Find all values less than the category 'medium'.

A < 'medium'

ans = 2x3 logical array

   0   0   1
   0   1   0

A value of logical 1 (true) indicates a value less than the category 'medium'.

Compare the rows of A.

A(1,:) < A(2,:)

ans = 1x3 logical array

   0   0   1

The function returns logical 1 (true) where the first row has a category value less than the second row.

Test Complex Numbers

Open Live Script

Create a vector of complex numbers.

A = [1+i 2-2i 1+3i 1-2i 5-i];

Find the values that are less than 3.

A(A < 3)

ans = 1×4 complex

   1.0000 + 1.0000i   2.0000 - 2.0000i   1.0000 + 3.0000i   1.0000 - 2.0000i

lt compares only the real part of the elements in A.

Use abs to find which elements are within a radius of 3 from the origin.

A(abs(A) < 3)

ans = 1×3 complex

   1.0000 + 1.0000i   2.0000 - 2.0000i   1.0000 - 2.0000i

The result has one less element. The element 1.0000 + 3.0000i is not within a radius of 3 from the origin.

Compare Dates

Open Live Script

Create a vector of dates.

A = datetime([2014,05,01;2014,05,31])

A = 2x1 datetime
   01-May-2014
   31-May-2014

Find the dates that occur before May 10, 2014.

A(A < '2014-05-10')

ans = datetime
   01-May-2014

Input Arguments

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`A`, `B` — Operands
scalars | vectors | matrices | multidimensional arrays

Operands, specified as scalars, vectors, matrices, or multidimensional arrays. Inputs A and B must either be 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.

You can compare numeric inputs of any type, and the comparison does not suffer loss of precision due to type conversion.

If one input is an ordinal categorical array, the other input can be an ordinal categorical array, a cell array of character vectors, or a single character vector. A single character vector expands into a cell array of character vectors of the same size as the other input. If both inputs are ordinal categorical arrays, they must have the same sets of categories, including their order. See Compare Categorical Array Elements for more details.
If one input is a datetime array, the other input can be a datetime array, a character vector, or a cell array of character vectors.
If one input is a duration array, the other input can be a duration array or a numeric array. The operator treats each numeric value as a number of standard 24-hour days.
If one input is a string array, the other input can be a string array, a character vector, or a cell array of character vectors. The corresponding elements of A and B are compared lexicographically.

Compatibility Considerations

expand all

Implicit expansion change affects arguments for operators

Behavior changed in R2016b

Starting in R2016b with the addition of implicit expansion, some combinations of arguments for basic operations that previously returned errors now produce results. For example, you previously could not add a row and a column vector, but those operands are now valid for addition. In other words, an expression like [1 2] + [1; 2] previously returned a size mismatch error, but now it executes.

If your code uses element-wise operators and relies on the errors that MATLAB^® previously returned for mismatched sizes, particularly within a try/catch block, then your code might no longer catch those errors.

For more information on the required input sizes for basic array operations, see Compatible Array Sizes for Basic Operations.

Implicit expansion change affects ordinal `categorical` arrays, `datetime` arrays, and `duration` arrays

Behavior changed in R2020b

Starting in R2020b, lt supports implicit expansion when the arguments are ordinal categorical arrays, datetime arrays, or duration arrays. Between R2020a and R2016b, implicit expansion was supported only for numeric and string data types.

Extended Capabilities

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

This 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 Verilog and VHDL code for FPGA and ASIC designs using HDL Coder™.

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

This function fully supports GPU arrays. 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).

Documentation

lt, <

Syntax

Description

Examples

Test Vector Elements

Replace Elements of Matrix

Compare Values in Categorical Array

Test Complex Numbers

Compare Dates

Input Arguments

`A`, `B` — Operands
scalars | vectors | matrices | multidimensional arrays

Compatibility Considerations

Implicit expansion change affects arguments for operators

Implicit expansion change affects ordinal `categorical` arrays, `datetime` arrays, and `duration` arrays

Extended Capabilities

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

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 Verilog and VHDL code for FPGA and ASIC designs using HDL Coder™.

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

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

See Also

Topics

MATLAB Documentation

Support

Documentation

lt, <

Syntax

Description

Examples

Test Vector Elements

Replace Elements of Matrix

Compare Values in Categorical Array

Test Complex Numbers

Compare Dates

Input Arguments

A, B — Operands scalars | vectors | matrices | multidimensional arrays

Compatibility Considerations

Implicit expansion change affects arguments for operators

Implicit expansion change affects ordinal categorical arrays, datetime arrays, and duration arrays

Extended Capabilities

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

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 Verilog and VHDL code for FPGA and ASIC designs using HDL Coder™.

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

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

See Also

Topics

MATLAB Documentation

Support

`A`, `B` — Operands
scalars | vectors | matrices | multidimensional arrays

Implicit expansion change affects ordinal `categorical` arrays, `datetime` arrays, and `duration` arrays

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

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 Verilog and VHDL code for FPGA and ASIC designs using HDL Coder™.

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

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