gt, >

Determine greater than

Syntax

A > B

gt(A,B)

Description

A > B returns a logical array or a table of logical values with elements set to logical 1 (true) where A is greater than B; otherwise, the element is logical 0 (false). The test compares only the real part of numeric arrays. gt returns logical 0 (false) where A or B have NaN or undefined categorical elements.

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

Examples

Test Vector Elements

Determine if vector elements are greater than a given value.

Create a numeric vector.

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

Test the vector for elements that are greater than 10.

A > 10

ans = 1×8 logical array

   0   1   1   0   0   1   0   1

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 greater than 10.

A(A > 10)

ans = 1×4

    12    18    11    15

The result is a subset of the elements in A.

Replace Elements of Matrix

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 greater than 9 with the value 10.

A(A > 9) = 10

A = 4×4

    10     2     3    10
     5    10    10     8
     9     7     6    10
     4    10    10     1

The result is a new matrix whose largest element is 10.

Compare Values in Categorical Array

Create an ordinal categorical array.

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

A = 2×3 categorical
     large       medium      small 
     medium      small       large 

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

Find all values greater than the category 'medium'.

A > 'medium'

ans = 2×3 logical array

   1   0   0
   0   0   1

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

Compare the rows of A.

A(1,:) > A(2,:)

ans = 1×3 logical array

   1   1   0

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

Test Complex Numbers

Create a vector of complex numbers.

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

Find the values that are greater than 2.

A(A > 2)

ans = 
5.0000 - 1.0000i

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

Use abs to find which elements are outside a radius of 2 from the origin.

A(abs(A) > 2)

ans = 1×4 complex

   2.0000 - 2.0000i   1.0000 + 3.0000i   1.0000 - 2.0000i   5.0000 - 1.0000i

The result has more elements since abs accounts for the imaginary part of the numbers.

Compare Dates

Create a vector of dates.

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

A = 2×1 datetime
   01-May-2014
   31-May-2014

Find the dates that occur after May 10, 2014.

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

ans = datetime
   31-May-2014

Compare Tables

Since R2023a

Create two tables and compare them. The row names (if present in both) and variable names must be the same, but do not need to be in the same orders. Rows and variables of the output are in the same orders as the first input.

A = table([1;2],[3;4],VariableNames=["V1","V2"],RowNames=["R1","R2"])

A=2×2 table
          V1    V2
          __    __

    R1    1     3 
    R2    2     4 

B = table([4;2],[3;1],VariableNames=["V2","V1"],RowNames=["R2","R1"])

B=2×2 table
          V2    V1
          __    __

    R2    4     3 
    R1    2     1 

A > B

ans=2×2 table
           V1       V2  
          _____    _____

    R1    false    true 
    R2    false    false

Input Arguments

A, B — Operands

scalars | vectors | matrices | multidimensional arrays | tables | timetables

Operands, specified as scalars, vectors, matrices, multidimensional arrays, tables, or timetables. 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, or a string scalar or character vector that represents a categorical value. If both inputs are ordinal categorical arrays, they must have the same sets of categories, including their order. For more information, see Compare Categorical Array Elements.

• If one input is a datetime array, the other input can be a datetime array, or a string scalar or character vector that represents a date and time. For more information, see Compare Dates and Time.

• If one input is a duration array, the other input can be a duration array, a string scalar or character vector that represents a length of time, or a numeric array where each element represents a number of fixed-length 24-hour days. For more information, see Compare Dates and Time.

• 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. For more information, see Compare Text.

Inputs that are tables or timetables must meet the following conditions: (since R2023a)

• If an input is a table or timetable, then all its variables must have data types that support the operation.

• If only one input is a table or timetable, then the other input must be a numeric or logical array.

• If both inputs are tables or timetables, then:

  • Both inputs must have the same size, or one of them must be a one-row table.

  • Both inputs must have variables with the same names. However, the variables in each input can be in a different order.

  • If both inputs are tables and they both have row names, then their row names must be the same. However, the row names in each input can be in a different order.

  • If both inputs are timetables, then their row times must be the same. However, the row times in each input can be in a different order.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | string | categorical | datetime | duration | table | timetable
Complex Number Support: Yes

Extended Capabilities

Tall Arrays

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

The gt 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 gt 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

R2023a: Perform operations directly on tables and timetables

The gt operator supports operations directly on tables and timetables without indexing to access their variables. All variables must have data types that support the operation. For more information, see Direct Calculations on Tables and Timetables.

R2020b: Implicit expansion change affects ordinal categorical arrays, datetime arrays, and duration arrays

Starting in R2020b, gt 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.

R2016b: Implicit expansion change affects arguments for operators

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.