fillmissing — Fill missing entries using constant, neighbor, interpolation, or summary methods.
fillmissing(A, method, ...) replaces supported missing values while preserving the input shape. Typed-integer input is a mode-gated RunMat extension: integer classes have no standard missing value, so the result is an exact same-class no-op and the optional filled-entry mask is all false. Integer data nested in table variables or cell contents is a separately declared aggregate extension and is classified before resident children are gathered.
Syntax
B = fillmissing(A, method, ...)Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
A | Any | Yes | — | Input value. |
args | Any | Variadic | — | Method, dimension, or option arguments. |
Returns
| Name | Type | Description |
|---|---|---|
B | Any | Result value. |
TF | LogicalArray | Logical mask of entries, rows, or columns that were filled or removed. |
Returned values from fillmissing depend on how many outputs the caller requests.
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 fillmissing works
- Numeric arrays support
"constant","previous","next","nearest","linear","mean", and"median". - String arrays support
"constant","previous","next", and"nearest". - Cell arrays support
"constant"replacement. - Tables apply filling variable-by-variable and return a table plus an optional logical mask; incompatible variable/method combinations report an error.
- The optional dimension argument may be supplied as
1,2, or as a"dim", valuepair. Without an explicit dimension, the first non-singleton dimension is used. - The optional logical mask marks entries that were actually filled; missing endpoints left unchanged by a neighbor method are false.
- Complex and sparse array filling is not implemented and is rejected instead of replacing an aggregate value.
- Current general gaps include
"spline","pchip","makima","mode", moving-window, KNN, custom-function, sample-point, known-location, maximum-gap, variable-selection, and append forms.
Examples
Fill by interpolation
B = fillmissing([1 NaN 3], 'linear')Expected output:
B = [1 2 3]Fill with a constant
B = fillmissing([1 NaN 3], 'constant', 0)Expected output:
B = [1 0 3]Using fillmissing with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how fillmissing changes the result.
Run a small fillmissing example, explain the result, then change one input and compare the output.
Related Missing functions
anymissing · ismissing · 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 fillmissing is executed, line by line, in Rust.
- View the source for fillmissing 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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