height — Return the number of rows in a table, timetable, or array.
height(A) returns the size of the first dimension as a scalar double. Integer array contents remain untouched because only authoritative shape metadata is inspected.
Syntax
n = height(A)Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
A | Any | Yes | — | Table, timetable, or array input. |
Returns
| Name | Type | Description |
|---|---|---|
n | IntegerScalar | Count. |
Errors
| Identifier | When | Message |
|---|---|---|
RunMat:table:InvalidArgument | Arguments or table metadata are invalid. | table: invalid argument |
RunMat:table:InvalidIndex | Table indexing is invalid. | table: invalid index |
RunMat:table:InvalidVariable | A table variable name or value is invalid. | table: invalid variable |
RunMat:readtable:IOError | readtable cannot open or read the requested file. | readtable: file read failed |
RunMat:readtable:UnsupportedFileType | readtable receives a file type outside the text or spreadsheet import backends. | readtable: unsupported file type |
How height works
- Tables and timetables return their row count.
- Numeric, complex, logical, character, cell, datetime, duration, and categorical arrays return the size of dimension one.
- Every integer class has the same structural contract; values are not materialized or converted.
- The result is scalar double. Counts outside exact binary64 range are explicitly outside the current representable contract.
Example
Count matrix rows
n = height(uint64(zeros(5, 3)))Expected output:
n = 5Using height with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how height changes the result.
Run a small height example, explain the result, then change one input and compare the output.
Related Table functions
array2table · array2timetable · categorical · cell2table · dictionary · groupsummary · head · iscategorical · isordinal · istable · istimetable · ordinal · pivot · rowfilter · struct2table · table · table2array · table2cell · table2struct · table2timetable · timerange · timetable · timetable2table · uitable · vartype · width
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how height is executed, line by line, in Rust.
- View the source for height in Rust on GitHub
- Learn how the RunMat runtime works
- Found a bug? Open an issue with a minimal reproduction.
About RunMat
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