test — Return test-set masks from a cvpartition object.
test(c) returns a logical test mask for single-test-set partitions. test(c,i) returns masks for selected K-fold, leaveout, or custom test sets.
Syntax
mask = test(c)
mask = test(c, i)
mask = test(c, "all")Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
c | Any | Yes | — | cvpartition object. |
i | Any | No | — | One-based test-set index, vector of indices, or 'all'. |
Returns
| Name | Type | Description |
|---|---|---|
mask | LogicalArray | Logical observation mask for one or more test sets. |
Errors
| Identifier | When | Message |
|---|---|---|
RunMat:cvpartition:InvalidArgument | Inputs, partition kinds, dimensions, indices, or name-value options are malformed. | cvpartition: invalid argument |
RunMat:cvpartition:Internal | RunMat cannot allocate or construct a partition output. | cvpartition: internal error |
How test works
test(c)works for holdout, resubstitution, and custom partitions with one test-set column.test(c,i)accepts a one-based single- or double-precision scalar or vector of test-set indices.test(c,'all')returns one logical mask column per test set.- RunMat mode also accepts logical and all eight typed-integer index classes. Typed integers are decoded exactly as structural indices without conversion through double.
- A resident index produces a resident logical mask owned by the same acceleration provider.
- For resubstitution partitions,
test(c)is all true because every observation is used for both training and testing.
Example
Get the test mask for one fold
c = cvpartition(6, 'KFold', 3);
idx = test(c, 2)Expected output:
`idx` is a 6-by-1 logical vector.Using test with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how test changes the result.
Run a small test example, explain the result, then change one input and compare the output.
FAQ
How do I retrieve all test masks?⌄
Use test(c,'all'); columns correspond to test-set indices.
Can i be an integer array?⌄
In RunMat mode, yes. Every integer class is read exactly. MATLAB-compatible mode accepts the documented single- and double-precision index forms.
Does test preserve GPU residency?⌄
Yes. When i is resident, RunMat gathers it through its owning provider and restores the logical output to that provider.
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Hist
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how test is executed, line by line, in Rust.
- View the source for test 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.
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