ismissing — Return a logical mask identifying missing entries.
ismissing(A) returns a logical result with true values where A contains missing data.
Syntax
TF = ismissing(A)Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
A | Any | Yes | — | Input value. |
Returns
| Name | Type | Description |
|---|---|---|
TF | LogicalArray | Logical missing-value mask. |
Errors
| Identifier | When | Message |
|---|---|---|
RunMat:missing:InvalidArgument | Arguments do not match a supported missing-value syntax. | missing-value builtin: invalid argument |
RunMat:missing:UnsupportedType | The input type has no missing-value representation in RunMat. | missing-value builtin: unsupported input type |
RunMat:missing:InternalError | Internal shape or table materialization fails. | missing-value builtin: internal error |
How ismissing works
- Numeric and complex values are missing when any stored component is
NaN. - String values are missing when they equal
<missing>case-insensitively. - Character-array rows are missing when blank or equal to
<missing>. - Cell arrays are tested element-by-element.
- Tables return a height-by-width logical array, one column per table variable.
- Datetime and duration objects are treated as missing when their internal numeric representation contains
NaN.
Examples
Detect NaN values
tf = ismissing([1 NaN 3])Expected output:
tf = [false true false]Detect table missing values
M = ismissing(T)Expected output:
M is a logical matrix with one column per table variable.Using ismissing with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how ismissing changes the result.
Run a small ismissing example, explain the result, then change one input and compare the output.
Related Missing functions
anymissing · fillmissing · missing · movmad · nanmean · nanmedian · nanmin · nanstd · nansum · nanvar · rmmissing · standardizeMissing
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how ismissing is executed, line by line, in Rust.
- View the source for ismissing 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.
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