cdf — Evaluate a fitted or named probability distribution cumulative distribution function.
cdf(pd,x) evaluates the cumulative distribution function for a ProbabilityDistribution object returned by fitdist. cdf(distname,x,params...) evaluates supported named distributions directly.
Syntax
p = cdf(pd, x)
p = cdf(distname, x, params)
p = cdf(pd, x, "upper")
p = cdf(distname, x, params, "upper")Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
pd | Any | Yes | — | ProbabilityDistribution object returned by fitdist. |
x | NumericArray | Yes | — | Sample data or evaluation points. |
distname | StringScalar | Yes | — | Distribution name. |
A...D | Any | Variadic | — | Named-distribution parameters, followed optionally by "upper". |
Returns
| Name | Type | Description |
|---|---|---|
y | NumericArray | Distribution function values. |
Errors
| Identifier | When | Message |
|---|---|---|
RunMat:fitdist:InvalidArgument | Sample data, distribution name, options, or evaluation inputs are malformed. | fitdist: invalid argument |
RunMat:fitdist:Numerical | Distribution parameter estimation fails to converge or is ill-conditioned. | fitdist: numerical failure |
RunMat:fitdist:Internal | RunMat cannot construct distribution outputs. | fitdist: internal error |
How cdf works
pdmust be a fitted distribution object returned byfitdist, ordistnamemust name a supported distribution.- Supported named distributions are
"Normal","Exponential","Lognormal","Gamma","Weibull", and"Poisson"; named parameters may be scalars or arrays with the same size as other nonscalar numeric inputs. xand named-distribution parameters acceptsingleordoubleunder MATLAB-compatible semantics; scalar inputs expand to the common nonscalar shape and the output uses that shape.- Appending
"upper"computes the complementary probability directly, including stable extreme-tail formulas for the supported families. - Typed-integer
xand typed-integer named parameters are independent RunMat-only extensions across all eight integer classes; logical numeric inputs are another RunMat-only extension. - Admitted typed integers must be exactly representable as binary64 at the distribution boundary, and resident inputs return resident output on the first owning provider.
- The output is single when any numeric
xor named parameter input is single, otherwise double. Supported fitted distributions are normal, exponential, lognormal, gamma, Weibull, and Poisson.
Examples
Evaluate a fitted normal CDF
pd = fitdist([1;2;3], "Normal"); p = cdf(pd, 2)Evaluate a named Poisson CDF
p = cdf("Poisson", 2, 3)Evaluate a normal upper tail with scalar expansion
p = cdf("Normal", single([0;2]), [0;1], 1, "upper")Using cdf with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how cdf changes the result.
Run a small cdf example, explain the result, then change one input and compare the output.
FAQ
How do I compute inverse probabilities?⌄
Use icdf(pd,p) with the fitted distribution object.
Related Stats functions
Summary
binocdf · boxplot · cdfplot · chi2cdf · corr · corrcoef · corrcov · cov · cov2corr · dummyvar · 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
binornd · bootstrp · datasample · dividerand · exprnd · gamrnd · lhsdesign · mvnrnd · normrnd · random · randsample · rng · trnd · unidrnd · unifrnd · wblrnd
Hist
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how cdf is executed, line by line, in Rust.
- View the source for cdf 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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