false — Create logical arrays filled with false values in MATLAB and RunMat.
false creates logical arrays filled with false values. Scalar, vector, matrix, and N-D sizing forms follow MATLAB semantics.
Syntax
L = false()
L = false(n)
L = false(size_vector)
L = false(m, n, ...)
L = false(prototype)
L = false(..., "logical")
L = false(..., "like", prototype)Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
n | SizeArg | Yes | — | Square size. |
size_vector | SizeArg | Yes | — | Size vector defining output dimensions. |
dims | SizeArg | Variadic | — | Dimension sizes. |
prototype | LikePrototype | Yes | — | Prototype value when no numeric dimension arguments are provided. |
typename | StringScalar | No | "logical" | Class override keyword (logical). |
like_kw | StringScalar | Yes | "like" | Like keyword. |
prototype | LikePrototype | Yes | — | Prototype array used for class/device. |
Returns
| Name | Type | Description |
|---|---|---|
L | LogicalArray | Logical output array. |
Errors
| Identifier | When | Message |
|---|---|---|
| — | The 'like' keyword is provided without a prototype argument. | false: expected prototype after 'like' |
| — | The 'like' keyword is provided multiple times. | false: multiple 'like' specifications are not supported |
| — | A trailing option string is not supported. | false: unrecognised option |
| — | Dimension arguments fail numeric/shape parsing. | false: dimension arguments must be numeric and nonnegative |
How false works
false()returns the scalar logicalfalse.false(n)returns an n x n logical array of false values.false(m, n, ...)returns a logical array with the requested dimensions.false(sz)accepts a size vector (row or column) and returns an array with prod(sz) elements arranged using MATLAB column-major ordering.false(A)returns a logical array of false with the same size asA.false(___, 'like', prototype)uses the prototype only for sizing; the result is still a host logical array.false(___, 'logical')is accepted for MATLAB compatibility and has no effect.
Examples
Creating a 2x3 logical array of false values
mask = false(2, 3)Expected output:
mask = [0 0 0; 0 0 0]Creating a logical array from a size vector
dims = [1 4 2];
mask = false(dims)Expected output:
mask =
1x4x2 logical array
0 0 0 0
0 0 0 0Creating a false mask with the same size as an existing array
A = rand(2, 2);
mask = false(A)Expected output:
mask =
2x2 logical array
0 0
0 0Using false with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how false changes the result.
Run a small false example, explain the result, then change one input and compare the output.
FAQ
What does false() return?⌄
It returns the logical scalar false.
Does false(n) create a square array?⌄
Yes. false(n) returns an n x n logical array of false values, matching MATLAB behavior.
How does false(sz) interpret a size vector?⌄
A row or column vector is treated as the full set of dimensions, so false([2 3 4]) yields a 2x3x4 logical array.
Does false keep results on the GPU?⌄
No. The builtin always returns a host logical array. gpuArray inputs are only used to infer the output size.
Is the 'logical' option required?⌄
No. false always returns logical values; the 'logical' option is accepted only for MATLAB compatibility.
Related Array functions
Creation
colon · eye · fill · inf · linspace · logspace · magic · meshgrid · nan · ones · peaks · rand · randi · randn · randperm · range · true · zeros
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how false is executed, line by line, in Rust.
- View the source for false in Rust on GitHub
- Learn how the RunMat runtime works
- Found a bug? Open an issue with a minimal reproduction.
About RunMat
RunMat is an open-source runtime that executes MATLAB-syntax code blazing on any GPU. It is licensed under the Apache 2.0 license.
- RunMat automatically optimizes your math for GPU execution on Apple, Nvidia, and AMD hardware. No code changes needed. Simulations that took hours now take minutes.
- Start running code in seconds. RunMat runs in the browser, on the desktop, or from the CLI. No license server, no IT ticket.