dummyvar — Create dummy-variable columns for grouping variables.
dummyvar(group) converts grouping variables into a numeric design matrix with one dummy column per level.
Syntax
D = dummyvar(group)Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
X | Any | Yes | — | Input labels. |
Returns
| Name | Type | Description |
|---|---|---|
D | NumericArray | Dummy-variable design matrix. |
Errors
| Identifier | When | Message |
|---|---|---|
RunMat:dummyvar:InvalidArgument | Inputs, dimensions, classes, output types, or options are malformed. | encoding: invalid argument |
RunMat:dummyvar:Internal | Internal conversion or allocation fails. | encoding: internal error |
How dummyvar works
- Numeric vector inputs use positive integer levels
1:max(group);NaNrows becomeNaNacross that grouping variable's dummy columns. - The documented numeric input classes are single and double. Typed integer grouping values are a compatibility-gated RunMat extension supporting all eight signed and unsigned classes. RunMat validates sign and the bounded feasible output domain from exact integer storage before converting feasible levels, which are below the binary64 exact-integer boundary; wider levels reject with a controlled output-size error. The output remains double.
- Numeric row and column vectors are treated as one grouping variable; nonscalar numeric matrices treat each column as a separate grouping variable and concatenate the dummy columns for each variable.
- Cell arrays can hold multiple grouping variables when supplied as a row cell array; cell-string vectors are encoded by first appearance.
- Categorical inputs use the full category order, including categories not observed in the input values.
- String, character-row, logical, and cell-string grouping variables are supported by RunMat.
- GPU grouping values are a separately gated RunMat extension and are rejected before provider access when compatibility extensions are disabled.
Example
Encode numeric group levels
D = dummyvar([1; 2; 1])Expected output:
D is [1 0; 0 1; 1 0].Using dummyvar with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how dummyvar changes the result.
Run a small dummyvar example, explain the result, then change one input and compare the output.
FAQ
Does dummyvar support missing labels?⌄
Yes. Numeric NaN, empty text, and <missing> text are treated as missing; missing numeric rows produce NaN dummy values.
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Summary
binocdf · boxplot · cdf · cdfplot · chi2cdf · corr · corrcoef · corrcov · cov · cov2corr · ecdf · filloutliers · fitdist · geomean · grpstats · harmmean · icdf · isoutlier · kstest · kurtosis · lsline · mad · mode · nanmax · normalize · normcdf · norminv · normpdf · onehotdecode · onehotencode · pdf · prctile · quantile · refline · rmse · skewness · tabulate · tcdf · tiedrank · tinv · tpdf · ttest2 · wblinv
Ml
bayesopt · classify · confusionmat · crossvalind · cvpartition · fitclinear · fitctree · fitlm · kmeans · knnsearch · lasso · lassoglm · linkage · lscov · mnrfit · optimizableVariable · pdist · pdist2 · perfcurve · predict · regress · ridge · squareform · test · training · tsne
Random
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Hist
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how dummyvar is executed, line by line, in Rust.
- View the source for dummyvar 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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