heteroTests News

0.11.2

Changes requested by the CRAN review of the 0.11.1 submission. No statistic, default or exported function changes.

• The Description field no longer says “in R”, and now cites the methods the package implements, with DOIs: White (1980), Breusch and Pagan (1979), Koenker (1981), Goldfeld and Quandt (1965), Harvey (1976), Cook and Weisberg (1983), Engle (1982), Bartlett (1937), Brown and Forsythe (1974) and Hartley (1950).

• No example reaches an unexported object through :::. The six help pages that did – for rhandleMissingValues(), rTEST_REQUIREMENTS, rvalidateDataInputs(), rvalidateDistributionalAssumptions(), rvalidateGroupingVariable() and rvalidateModelInputs() – document internal objects, where :: would fail. Their examples are removed rather than the objects exported.

• No example uses \dontrun{}. The recommendations example runs in well under a second and is unwrapped. The report example takes about ten seconds and needs pandoc, so it runs under \donttest{} behind rmarkdown::pandoc_available() and writes to tempdir(). The dashboard example is guarded by interactive(), since printing the Shiny application it returns starts a blocking server.

• The \donttest{} part of the performWhiteTestBootstrap() example uses 499 bootstrap replications rather than 999. With that part included, as R CMD check --as-cran runs it, the example took 5.0 to 5.7 seconds, over the five-second limit for examples; it now takes about 1.7 seconds.

0.11.1

Two panel p-values change value, though not their conclusions.

The panel p-values no longer underflow to zero

performBPRandomEffectsTest() and performPesaranTest() computed their upper tails as 1 - pchisq() and 1 - pnorm(). Both collapse to exactly zero once the statistic is large: at LM = 182.9 the subtraction returns 0 where the upper tail returns 1.1e-41, which is the value plm::plmtest() reports. A p-value of exactly zero is wrong, and it discards the magnitude that anything working on a log scale or applying a multiplicity correction needs. Both now pass lower.tail = FALSE.

Both are now checked against plm

Neither statistic had a reference implementation among the packages the accuracy table compares against, which is why both were wrong until 0.11.0 and why simulated size was the only thing that caught them. plm has had both all along.

performBPRandomEffectsTest() reproduces plm::plmtest(type = "bp") exactly, and performPesaranTest() reproduces plm::pcdtest(model = "pooling"), both to 1e-8 across N = 20/30/40 and T = 5/6/8.

The model argument is the part worth recording. pcdtest() defaults to model = NULL, which tests the series rather than any model’s residuals and gives 0.817 where this package gives 1.580. performPesaranTest() takes a fitted lm, whose residuals are identical to the pooling residuals, so "pooling" is the comparison that puts both on the same quantity; "within" and "random" give 1.220 and 1.258, which are different estimands rather than disagreements.

plm and withr join Suggests. The tests attach plm with withr::local_package() rather than calling through ::, because pcdtest() calls plm() internally without qualifying the namespace and fails when the package is only installed.

Continuous integration

• R CMD check --as-cran no longer runs on every merge. CRAN submission is not the near-term target, and that job costs about an hour: it installs a LaTeX toolchain and every check dependency, then rebuilds the vignettes. It had also stopped completing – three consecutive runs on main were cancelled or left queued inside it – so it was a gate producing a signal nobody received. It now runs weekly and on workflow_dispatch.
• A concurrency group is added, keyed by pull request number for pull requests and by commit for everything else. A ref-keyed group would have put pushes, the weekly schedule and manual dispatches on main into one queue, and GitHub keeps only one pending run per group, so a third arrival would cancel the pending one.

0.11.0

Two panel statistics were wrong against their published definitions. Both change, hence the minor version.

Where these came from

A size and power sweep over all 32 exported perform*Test() functions, each driven by a null and an alternative appropriate to what it actually tests. Twenty-six of the twenty-eight heteroscedasticity tests hold their nominal level: at 400 replications and n = 150, size ranges from 3.0% to 6.2% against a Monte Carlo standard error of 1.1%, with power between 95% and 100% against sd = x^2. The two below did not, and neither has a reference implementation among the packages the accuracy table compares against, so only simulation would have found them.

performBPRandomEffectsTest() rejected a third of the time under the null

The statistic was

T^2 / (2(T - 1)) * sum_i (sum_t e_it)^2 / sum_it e_it^2

against Breusch and Pagan’s (1980) equation 5,

nT / (2(T - 1)) * [ sum_i (sum_t e_it)^2 / sum_it e_it^2 - 1 ]^2

The bracketed ratio is close to one under the null, and the published statistic measures its squared departure from one. Dropping the - 1 and the square leaves a quantity that sits at T^2 / (2(T - 1)) – 3.6 for T = 6, against a chi-square(1) critical value of 3.841. Measured median statistic 3.548, and size 32.5% against a nominal 5%. It is now 5.8%, with power 100% against random intercepts.

The documentation was wrong in the same place. The help page was titled a test for random effects but described a test for “heteroscedasticity in random effects models”, and the roxygen claimed it tested whether the effect’s variance varies across units. It tests whether an individual effect is present at all, and does not respond to heteroscedasticity: against errors with sd = x^2 the corrected statistic rejects 3.2% of the time, which is the nominal level rather than power.

performPesaranTest() never rejected

The statistic was sqrt(N(N-1)/(2T)) times the mean pairwise residual correlation, against Pesaran’s (2004, 2015)

CD = sqrt( 2T / (N(N-1)) ) * sum_{i<j} rho_ij

which is the same quantity multiplied by T. The implemented version was therefore exactly 1/T too small: at T = 8 its standard deviation was 0.133 where the published form gives 1.067, and since the reference distribution is standard normal, size was 0.0%. It is now 6.5%, with power 100% against a common time factor.

The pairwise correlations are also computed with a single cor() call rather than a double loop that grew a vector by c().

Also

• performRESETTest was checked in the same sweep and is correct: size 5.2%, power 100% against an omitted quadratic term.
• performGQTest reproduces lmtest::gqtest() exactly at matched fraction – the difference is zero at 0.1, 0.2 and 0.3. It cannot reproduce that function’s default, because lmtest omits no central observations by default and performGQTest() requires fraction strictly between 0 and 1.
• tests/testthat/test-panel-statistics.R pins both corrections by simulated size rather than by a stored value, since a stored value would not have caught either fault. ## 0.10.0

rbootstrap_test_statistic() now resamples under the null. Its p-value changes, and so does the p.value_bootstrap field of the two robust tests, hence the minor version.

The bootstrap p-value could not detect anything

The helper resampled rows of the data with replacement, refitted, and recomputed the statistic. Those replicates follow the statistic’s distribution under whatever variance structure the data actually have, not under the null: they are centred on the observed statistic, so comparing the two returns roughly one half however strong the heteroscedasticity is.

Measured over 400 samples at n = 120, B = 199, testing Koenker’s statistic:

Zero rejections under a strong alternative. The p-value was exported directly and also reached users as p.value_bootstrap from performWhiteTestRobust() and performBPTestRobust() when called with bootstrap = TRUE.

resample now takes "null", which is the default. The response is regenerated as fitted + e*, with e* drawn with replacement from the residuals after dividing by sqrt(1 - h_i) and centring, so the regenerated data satisfy homoscedasticity by construction. Size is 5.0% (Monte Carlo standard error 1.1%) and power is 99.2% against sd = 0.5x and 100% against sd = x^2. Size holds at 5.0% under homoscedastic t_5 errors as well, so the calibration does not depend on Gaussian tails – which matters here, because Bartlett’s and Hartley’s tests reject about 24% of the time against the same heavy-tailed null (see inst/validation/README.md).

The leverage correction is not decorative. OLS residuals have variance sigma^2 (1 - h_i), so resampling them unscaled under-disperses the regenerated errors; a version without it rejected about 13% of the time under the null. This is the construction performWildBootstrapTest() already used.

resample = "pairs" is still available and still returns the replicates and the interval, which describe the statistic’s variability perfectly well. It now returns NA for p_value rather than a number that cannot be interpreted.

Null-imposed resampling is restricted to a Gaussian lm whose response is a plain variable, and errors otherwise. Two cases previously ran and returned a plausible p-value from replicates that meant nothing: a transformed response such as log(y) ~ x, where fitted() is on the log scale and the data column holds y, so refitting took the logarithm twice and returned p = 1; and a glm, where the refit used safe_lm() and dropped the family and link, returning p = 0.952 for a Poisson model. resample = "pairs" resamples rows and is unaffected by the transformed-response case, so it remains available there.

A glm is now refused by both strategies. Each replicate is refitted with least squares whichever strategy is used, so on a Poisson fit of counts the coefficients move from (0.457, 0.406) on the log link to (-0.931, 2.281) on the identity scale: the replicates describe a different model from the one passed. The helper documented glm support it never had.

Percentile intervals are not confidence intervals

The ci component was documented as a “percentile confidence interval for the statistic”. It is a percentile interval of the bootstrap distribution: it summarises where the resampled statistic falls, is not an interval for a parameter, and carries no coverage guarantee. The documentation says so. This closes the corresponding roadmap item.

0.9.0

fitWLS() now estimates its weights from a variance model. The numbers it returns change, hence the minor version.

fitWLS() produced unusable standard errors

The weights were the inverse squared residuals of the initial fit, w_i = 1 / e_i^2. A squared residual is a one-degree-of-freedom estimate of sigma_i^2, far too noisy to invert, and inverting it hands the weight to whichever observations the first fit happened to reproduce most closely. On quakes that meant five of a thousand points carrying 99.5% of the total weight, with a largest-to-median weight ratio of about 1e+07.

Two consequences, measured over 2000 replications of y = 1 + 2x + e, sd(e) = 0.5x, at n = 200:

The point estimate was unbiased but no more efficient than OLS, so the function delivered none of the efficiency that is the purpose of weighting; and its intervals covered the truth about a tenth of the time, because the weighted residual sum of squares collapses towards n and the reported sigma is approximately sqrt(n / (n - p)) whatever the data.

fitWLS() now regresses log(e^2) on the model’s own design matrix and weights by 1 / exp(fitted), the standard feasible-GLS recipe. That recovers the efficiency (SD 19% below OLS, close to the oracle) and calibrates the intervals. Zero residuals are floored before the logarithm by the same helper the log-variance tests use, and an unusable variance model falls back to equal weights, which degrades to the original OLS fit rather than failing.

The estimated variances are attached to the result as the "variance_model" attribute.

Knock-on corrections

• compareModelDiagnostics() can now run White’s test on a WLS fit. It previously reported NA there, correctly, because the degenerate weighting made the weighted fit perfectly explained; that cell has now held three different things across three releases and the test records all three.
• autoCompareRemediations() compares AIC and RMSE across OLS, WLS and robust fits. The WLS row was computed from the degenerate fit and is now meaningful.
• The WLS section of real_world_case_studies.Rmd no longer needs its warning that the weighted variance profile was flat by arithmetic rather than by fit. On quakes the profile now falls from a 6.6-fold spread across thirds of the fitted range to 2.95-fold, which reflects the data.

Metadata

• The maintainer affiliation is now recorded identically in CITATION.cff, inst/CITATION, .zenodo.json, README.md and the paper. Only .zenodo.json carried the current name; the rest still had the former one.

0.8.1

CRAN preparation. No change to any statistic or to the public API.

The bundled Boston dataset is gone

boston_housing was a byte-identical copy of MASS::Boston – all 506 rows and all 14 columns. Shipping it under this package’s Apache License (>= 2.0) put a verbatim copy of GPL-2 | GPL-3 material under Apache terms, which is at best a question a CRAN reviewer would ask, and cran-comments.md volunteered it.

The justification recorded there – that the copy let examples run “without attaching MASS” – did not hold either: MASS is a hard Imports dependency, so it is installed regardless.

Examples, vignettes and the tutorial notebooks now use R’s built-in quakes data, which lives in datasets and is attached by default. Nothing is redistributed, so the licensing question disappears rather than being argued. The two datasets the package still ships, diagnostic_data and hetero_data, are simulated.

The replacement was chosen on evidence, not convenience. Against stations ~ mag + depth (n = 1000, R-squared 0.74) White gives p = 2e-25, Breusch-Pagan p = 2e-42 and Koenker p = 7e-25, and the HC3 standard error for mag is 1.34 times the OLS one – enough for the notebooks’ robust-versus- classical comparison to keep its point. The response is a count, so its variance rises with its mean: the textbook mechanism, which makes it a better teaching example than the original. Candidates with stronger p-values (ChickWeight, Theoph, DNase, Loblolly, Orange) were rejected because they are repeated-measures data, where residuals are correlated within subject and these tests’ independence assumption does not hold.

Dropping the dataset also drops the black column, the transformed racial-composition variable that led scikit-learn to remove this data in 1.2.

Packaging

• Three references used \url{https://doi.org/...} where CRAN asks for \doi{}, the form the rest of the package already used. Fixed in performStudentizedBPTest, performSzroeterTest and performWhiteTestBootstrap, and in the roxygen sources so a regeneration produces the same form.
• README no longer lists two limitations that were fixed in 0.8.0: the renv.lock drift and the bundled dataset.

0.8.0

The API review that the validation effort was sequenced towards. Six exports are removed. This is a breaking change, hence the minor version.

Three returned nothing but a migration error, having been withdrawn once their statistics were shown not to work:

Three computed a valid statistic under a name that promised a different method, duplicating a test that remains:

The package has not been released on CRAN, so no published contract is broken. tests/testthat/test-public-api.R records the removals and checks that every replacement named above is still exported.

Two dead fallback routes went with them: hc_covariance was registered as a recovery path for quantile_regression and high_dimensional, and hc_covariance_hc0 as a custom fallback, both calling a function that only ever raised an error.

Packaging

• The pkgdown workflow now deploys. It called build_site_github_pages(), which writes docs/, and then stopped: there was no deploy step and no gh-pages branch, so the job reported success while nothing was published. That is why the URLs in DESCRIPTION and inst/CITATION returned 404.
• renv.lock now records all 38 declared non-base dependencies, up from 14. renv::restore() previously pinned about a third of them, and the Docker build only worked because remotes::install_local() resolves the remainder from CRAN at whatever version is current. The R version moves to 4.5.1, which is where the recorded versions come from.

0.7.2

Pass C of the statistical validation matrix: the methods with the least reference coverage. Six were sound and one needed a fix. Two are withdrawn because their statistics cannot detect heteroscedasticity at all, and two more are valid statistics under names that promise something else.

Withdrawn

• performRiceTest() compared Rice’s (1984) difference-based variance estimator with the mean squared residual and referred the ratio to an F distribution. For independent residuals E[(e_i - e_{i-1})^2] is s2_i + s2_{i-1}, so the numerator estimates the mean of the variances and so does the denominator: the ratio sits at one under any variance pattern. Simulated means were 1.00 under homoscedasticity, under sigma = 0.2 + 1.2x, under sigma = exp(x) (a fiftyfold spread) and under a twentyfold step change, and empirical size was 0.000. Adding an ordering argument does not repair it. Use performSzroeterTest() or performGQTest() instead.

• performCurryWalshTest() passed an unstandardised Moran’s I to 2 * (1 - pnorm(abs(I))). Moran’s I has null expectation -1/(n-1) and a weights-dependent variance, and is bounded near one, so it essentially never reached 1.96: it rejected in 0.0% of samples under strong heteroscedasticity and returned p = 0.875 on clustered variance. performSpatialHeteroTest() already does this correctly via spdep::moran.mc().

Both retain their exports and signal a migration error, following the withdrawn HC covariance precedent.

Corrected

• performDavidianCarrollTest() failed with NA/NaN/Inf in 'y' when a residual was exactly zero. It now uses the shared log-residual floor, as Harvey and Park do.

Documented rather than removed

• performOrderedLMTest() sorts the rows and refits, which returns the same residuals permuted, so order_by cannot change the statistic and the result is identical to performKoenkerTest(). It now warns that the argument has no effect.
• performCameronTrivediTest() is exactly the e^2 ~ yhat + yhat^2 F test, not the information-matrix test of Cameron and Trivedi (1990), which concerns overdispersion in count models. The help page now says what it computes.

Removing either redundant export is left to the API review.

Validated without change

performRankPermutationTest(), performHighDimensionalTest(), performWildBootstrapTest(), performQuantileRegressionTest(), performSpatialHeteroTest() and performPesaranTest() hold their nominal level and have power.

0.7.1

Pass B of the statistical validation matrix: the group-variance tests. This section was missing from the changelog when 0.7.1 shipped and is recorded here.

Statistical corrections

• Bug fix (critical): performOBrienTest() rejected on every input. O’Brien’s transformation produces one score per observation, whose group mean is that group’s variance. The implementation computed a single value per group and repeated it across that group’s observations, so the scores had no within-group variability: the one-way ANOVA had a residual sum of squares of zero, giving F on the order of 1e30 and p = 0 for any data, homoscedastic or not. Empirical size is now 4.8%.

• Bug fix (critical): performHartleyFmaxTest() used the wrong null distribution. The statistic is the largest of k group variances over the smallest, but the p-value came from pf(F, df, df), the distribution of a single variance ratio; the number of groups was computed and never used. Empirical size at a nominal 5%, groups of 30, was 0.0998 at two groups, 0.2238 at three, 0.3497 at four and 0.5626 at six. It now uses the maximum-F-ratio distribution and holds 0.05 throughout.

• performOBrienTest() also called safe_lm() without a data argument, so every call errored once the transformation was corrected.

Validated without change

performLeveneTest(), performBrownForsytheTest(), performBartlettTest() and performFlignerKilleenTest() reproduce car::leveneTest() with mean and median centring, stats::bartlett.test() and stats::fligner.test() to within 1e-8.

Documentation

• performModifiedBartlettTest() is Bartlett’s test under another name: the correction factor its documentation described as a modification is part of the standard definition. It is now documented as a compatibility alias.
• Bartlett’s per-group minimum was relaxed from three observations to two, which is what a sample variance requires.

0.7.0

This release is the first pass of a package-wide statistical validation effort. Pass A covers the classical regression diagnostics. Every test in this group was checked against an established implementation where one exists, and otherwise against a reconstruction of the primary reference, followed by Monte Carlo size and power measurement. Reference equivalence is asserted in tests/testthat/test-pass-a-reference.R; the simulation evidence is reproducible via inst/validation/pass-a-size-power.R and recorded in inst/validation/pass-a-size-power.csv.

Several of the corrections below change the value a test returns. They are breaking changes, and the minor version has been bumped accordingly.

Statistical corrections

• Bug fix (critical): performSzroeterTest() was standardised incorrectly and had no power. Szroeter’s (1978) rank-weighted statistic h = sum(i * e_(i)^2) / sum(e_(i)^2) has null mean (n + 1) / 2 and null variance (n^2 - 1) / (6n). The previous implementation rescaled h by the mean rank and then divided the centred statistic by a further sqrt(n), using an ad-hoc variance (n + 1)(2n + 1) / (12n). The net effect was to shrink the standardised statistic by a factor of roughly 2 / sqrt(n) — a factor of 5 at n = 100. In 5,000 replications the test rejected in 0.0% of samples under the null and under every alternative tried: it could not reject at any sample size or effect size. The statistic is now Szroeter’s Q, which attains 4.5% size and 87–91% power in the same designs. The test also gained an alternative argument ("greater", the default, for variance increasing with the ordering variable), and reports h in estimate.

• Bug fix: performNCVTest() did not compute the NCV test. It regressed the absolute residuals on the fitted values and reported a t statistic — a Glejser-type diagnostic — while documenting itself as equivalent to car::ncvTest(). It now computes the Cook–Weisberg score statistic: half the explained sum of squares from regressing e^2 / (RSS / n) on the variance model, referred to a chi-squared distribution. It reproduces car::ncvTest() to within 1e-8. A new var_formula argument selects a variance model other than the fitted values, matching car::ncvTest(var.formula = ).

• Bug fix: performCookWeisbergTest() returned the Koenker statistic. It computed n R^2 from regressing the raw squared residuals on the fitted values — that is, Stata’s estat hettest, iid fitted — while documenting itself as Stata’s estat hettest, fitted. It now computes the Cook–Weisberg score statistic and delegates to performNCVTest() so the two exports cannot drift apart. Note the trade-off this exposes: the score test assumes normal errors, and in simulation it over-rejects under heavy tails where the previous (mislabelled) statistic did not. performKoenkerTest() remains the kurtosis-robust choice and is now cross-referenced from both help pages.

• Change: performHarveyTest() now follows Harvey (1976). The variance regressors default to the model’s own explanatory variables rather than the fitted values and their square, and the statistic is the classical ESS / (pi^2 / 2) referred to a chi-squared distribution, where pi^2 / 2 is the null variance of log(chi^2_1). The previous behaviour is available as auxiliary = "fitted", and the studentized F form — which estimates that variance from the data instead of assuming normality, and holds size better under heavy tails — as studentize = TRUE.

• Harvey and NCV now take their degrees of freedom from the realised rank of the auxiliary design, so a rank-deficient variance model is not credited with degrees of freedom for columns that lm() aliased away.

• performHarveyTest() and performParkTest() now warn when a residual is numerically zero and has been floored before taking logarithms. A floored observation contributes log(.Machine$double.eps) ~ -36, roughly sixteen standard deviations below the mean of the null log(chi^2_1) distribution, and can dominate the auxiliary regression on its own.

• performParkTest(), performGlejserTest(), performNCVTest() and performCookWeisbergTest() now name their parameter element, so print.htest() labels the degrees of freedom instead of printing = 118.

Validated without change

performArchLMTest() and performMcLeodLiTest() were audited and required no change. ARCH LM reproduces Engle’s T R^2 auxiliary regression with T = n - q (the FinTS::ArchTest() convention) and McLeod–Li reproduces the Ljung–Box statistic on squared residuals with df = m, both to within 1e-10, with empirical size of 4.4% and 5.6% and power of 99% and 97% against an ARCH(1) alternative.

Diagnostic workflow

• Bug fix: compareModelDiagnostics() could report one test’s statistic under another test’s name. When a requested diagnostic fails, runHeteroTests() substitutes a fallback diagnostic and tags the result with the substitute’s name. compareModelDiagnostics() read the statistic without checking that tag, so a comparison table column headed white could contain, for example, an NCV statistic. It now reports NA and warns when a substitution occurred, since a numeric table has nowhere to carry the caveat.

  This masking is also why two existing tests changed expectations. Both were passing because the previously unvalidated performNCVTest() succeeded on degenerate models — including a perfectly explained fit — and so served as a fallback that always worked. With NCV validating its input, the underlying failures are now surfaced rather than papered over.

Source integrity

• Removed two shadowed duplicate definitions. performHCCovarianceTest() and performQuantileRegressionTest() each had two definitions in the source tree. The obsolete implementations in R/modern_diagnostics.R were loaded first and then silently overwritten by the corrected versions in R/zz_deprecated_hc_covariance.R and R/quantile_regression_joint.R. Runtime behaviour was correct only because of collation order; a partial sourcing, a file rename or a collation change would have resurrected the withdrawn HC pseudo-test and the superseded quantile comparison. The obsolete definitions and their roxygen blocks are gone, along with the now-unreachable .hc_adjustment() helper whose only caller was the deleted HC implementation.

Resampling inference

• Bootstrap and permutation p-values now consistently use the finite-simulation convention (1 + #{T_b >= T_obs}) / (B_eff + 1), where B_eff counts the replicates that converged. performWhiteTestBootstrap(), performWhiteTestEnhanced() and the shared rbootstrap_test_statistic() engine previously used the raw proportion #/B, which can return exactly zero — not an attainable p-value from a finite number of replicates — and is anti-conservative in the tail. performWildBootstrapTest() and performRankPermutationTest() already used the corrected form. tests/testthat/test-bootstrap-pvalue-convention.R pins all of them.

Packaging and continuous integration

• Fixed the vignette build, which was breaking R CMD build and therefore every platform’s check job. Three vignettes failed to build: bibliography.Rmd called algorithms_bibliography(), which has never existed as a function (the name belongs to a documentation-only help topic); comprehensive_guide.Rmd called simulate_hetero(n = 50) without the required beta0, beta1 and sigma_func arguments; and using_heteroTests.Rmd passed mtcars as the data for a model fitted on boston_housing, referenced the non-existent performGoldfeldQuandtTest(), contained an illustrative chunk using an undefined your_data placeholder, and had a malformed chunk fence that left ten lines of code outside any chunk. R CMD build now completes and all eight vignettes render.

• inst/CITATION modernised: 25 citEntry() calls converted to bibentry() (deprecated since R 4.2), a duplicate citHeader() that silently replaced the first removed, and the package version now read from meta$Version. The previous utils::packageDescription("heteroTests")$Version raised “$ operator is invalid for atomic vectors” during CRAN incoming checks when the package was not installed.

• The CI R-version matrix was rebuilt around R-devel, R-release and R-oldrel-1, with macOS and Windows on R-release, replacing the fixed 4.0/4.1/4.2/4.3 set. The minimum version declared in Depends: now has its own Ubuntu 22.04 job that installs hard dependencies only, so it reports on the package’s own R 4.0 compatibility rather than on whether modern Suggests still support R 4.0.

• Fixed a broken example that failed R CMD check. performQuantileRegressionTest() documented itself with mtcars, which has 32 observations, while the test requires at least 40. The example now uses boston_housing.

• Non-ASCII characters removed from R/messages.R and R/validation.R. The two occurrences inside string literals are now written as the escapes \u00b2 and \u2022; the en dashes in roxygen comments became ASCII hyphens.

• Resolved 18 duplicated \alias entries. man/simulate_hetero.Rd is a complete hand-written family page for simulate_hetero(), simulate_arch1() and every sigma_*() helper, but roxygen2 also generated a thinner page per helper, so each name was documented twice. The generated stubs are removed — several were incomplete, for example sigma_poly.Rd omitted a, b and c — and the corresponding roxygen blocks are marked @noRd so they do not reappear. The same applied to generate_benchmark_report, which is documented on the run_benchmark_suite page.

• Reconciled \usage sections that had drifted from their function signatures: performWhiteTest() (max_interactions), plot.HeteroDiagnostic() (plots) and summary.HeteroDiagnostic() (tests).

• Documented previously undocumented arguments in generateHeteroRecommendations.Rd, plot.power_analysis.Rd, print.htest_enhanced.Rd, test.HeteroDiagnostic.Rd and simulate_hetero.Rd, and merged the duplicated n entry on the last of these.

• .Rbuildignore now excludes .zenodo.json, CITATION.cff and CONTRIBUTING.md, which are repository metadata rather than package content. inst/validation/ is deliberately shipped so the size and power evidence travels with the package.

• Fixed a latent runtime failure in the dashboard. launchDiagnosticDashboard() used the magrittr pipe %>% in four places without importing it. DT and plotly are Suggests and are called with :: rather than attached, so the pipe was only ever resolved if one of them happened to be attached by something else. The calls are now nested.

• A second example failed R CMD check: performWhiteTestBootstrap() used mtcars (32 observations) while the bootstrap requires 50. It now uses a simulated 120-observation dataset, with the heavier replication counts moved under \donttest{}.

• Fixed 15 broken \link[stats:htest]{htest} cross-references. There is no htest topic in stats, so every one of these was a dangling link; they are now plain \code{htest}.

• Completed the NAMESPACE imports. AIC, cooks.distance, cov, lm.fit, model.frame, model.response, nobs, quantile, resid, terms and uniroot from stats, and head, object.size and tail from utils, were used without being imported. Column names referenced inside aes() are declared through utils::globalVariables().

• Removed the Author: and Maintainer: fields from DESCRIPTION, which had drifted from the values derived from Authors@R (the derived form carries the ORCID). Unescaped 15 \& sequences in .Rd files, and added _pkgdown.yml and LICENSE to .Rbuildignore.

• Fixed three defects in the benchmarking system, all of which surfaced once its example was actually reachable under R CMD check --run-donttest. run_benchmark_suite() aborted with “no rows to aggregate” whenever every measured difference was NA, because aggregate() drops NA responses and the guard only tested for zero rows. generate_benchmark_report() then failed with “argument 1 is not a vector” when called with profile_memory = FALSE, since it passed a NULL column to order(). And ht_extract_metrics() had no branch for car::ncvTest(), which returns ChiSquare/Df/p rather than the htest field names, so every accuracy row measured against car was silently NA. With that branch in place the benchmark now reports a p-value difference of about 1e-15 between performNCVTest() and car::ncvTest() – an independent confirmation of the correction described above.

• Fixed the Breusch-Pagan benchmark baseline. performBPTest() is the classical statistic, but the benchmark compared it against lmtest::bptest() with its default studentize = TRUE, i.e. the Koenker form. The pairing is now studentize = FALSE. With this and the car::ncvTest() extractor in place, all three baselines agree with our implementations to machine precision (0, 1.7e-16 and 1.2e-15), so the benchmark now doubles as a live reference-equivalence check.

• Fixed simulate_power_analysis(), whose effect size had no effect. It built the variance function as effect_size * sigma_func(x), but heteroscedasticity tests are invariant to multiplying every standard deviation by a constant, so every effect size produced statistically identical data and the reported power differed only by Monte Carlo noise. The effect size now interpolates between a constant variance and the supplied pattern, so 0 is homoscedastic and 1 is the pattern itself. Power against sigma_linear with White’s test now runs 0.04 / 0.07 / 0.33 / 0.96 across effect sizes 0 / 0.1 / 0.4 / 1.0, recovering the nominal level at zero effect.

• The Type I error test now sizes its tolerance from the Monte Carlo standard error rather than a fixed 0.03 margin, which at 200 replications was under two standard errors and failed by chance in roughly one run in seven.

• Raised the declared minimum R version to 4.1. Depends: R (>= 4.0.0) was unsatisfiable: ggplot2 and scales are hard Imports and both now require R >= 4.1, so the package could not be installed on R 4.0 whatever its own code did. The minimum-version CI job checks 4.1 accordingly.

• Fixed two CI jobs that had never run successfully. The spell check called spelling::spell_check_package(ignore = ), an argument that does not exist, so the step errored every time; inst/WORDLIST is read via use_wordlist instead. The benchmark job gated on heteroTests being no more than 50% slower than bare lmtest/car calls, which it cannot satisfy – it runs a validation layer those do not, and at n = 100 the baseline time rounds to zero, making the ratio infinite. The timing table is now reported as an artefact and the job gates on accuracy, which is the property that must not regress.

• Fixed the pkgdown deploy, which had been failing on main since before this release. man/algorithms_bibliography.Rd carried \usage{NULL}, which is what roxygen emits for a documentation-only topic and which pkgdown cannot parse. A topic that documents no function needs no usage section. This is why the package site was never published, and so why the URLs in DESCRIPTION and inst/CITATION returned 404.

• The automated release workflow now installs dependencies before R CMD build, which renders the vignettes and therefore needs the vignette builder. That step is gated on the version changing, so the omission had never fired until the 0.7.0 bump.

• Fixed generateDiagnosticReport(), which could not generate a report. The YAML front matter it writes put two mappings on one line (output: html_document:), so rmarkdown aborted with “mapping values are not allowed in this context”. html_document is now nested under output. The example is wrapped in \dontrun{}, so only a check passing --run-dontrun executed it, which is why it went unnoticed.

• The CRAN submission job now installs a LaTeX toolchain, and the pkgdown job installs rsconnect. Both were failing on missing dependencies rather than on anything in the package: the former reported pdflatex is not available, which R CMD check surfaces as a probable Rd problem, and the latter needs rsconnect to inspect inst/tutorials.

Documentation

• performGlejserTest() documents that the test is not asymptotically valid under asymmetric errors (Godfrey 1996; Im 2000), and that scanning several transformations and reporting the smallest p-value invalidates the nominal level.
• performParkTest() documents that its t statistic is valid only asymptotically, the auxiliary error being a strongly skewed log(chi^2_1) variate, and that a non-significant result speaks only to the single variable tested.

0.6.5

• Bug fix (statistical correctness): performBPTest()/performBreuschPaganTest() now compute the classical Breusch-Pagan statistic (half the explained sum of squares from the scaled squared residuals), matching lmtest::bptest(studentize = FALSE). It previously returned the studentized n R^2 statistic despite being documented as the classical, normality-based test.
• Bug fix (statistical correctness): performKoenkerTest() now implements Koenker’s (1981) studentized Breusch-Pagan statistic as n R^2 from regressing the squared residuals on the regressors, matching lmtest::bptest(studentize = TRUE) and performStudentizedBPTest(). It previously regressed the absolute residuals, which is not a recognized test and produced p-values without a valid chi-squared justification.
• The streaming variants performBPTestStreaming() and performKoenkerTestStreaming() were updated to stay algebraically equivalent to their exact counterparts.
• Bug fix: resolved a duplicate %||% operator definition whose two copies had conflicting semantics. Depending on collation order this could cause runHeteroTests() to abort with a “length > 1” coercion error when given a multi-column data frame. Both copies now share a single vector-safe definition.
• Bug fix (statistical correctness): performWildBootstrapTest() now generates its bootstrap reference distribution under the homoscedastic null by resampling leverage-standardised, centred residuals i.i.d. before applying the wild multiplier. The previous implementation multiplied the original (heteroscedastic) residuals by the wild weights, so the bootstrap distribution inherited the heteroscedasticity being tested for and the test had essentially no power (returning p ~ 0.5 on strongly heteroscedastic data). It now controls size and detects heteroscedasticity reliably; regression tests cover both.
• Packaging: R6 moved from Suggests to Imports (it is used at package load time), parallel added to Imports (used via ::), and the optional digest dependency (used for cache hashing) is now declared in Suggests. These resolve R CMD check “undeclared dependency” and load-time failures.
• Bug fix: performWhiteTest() now drops perfectly collinear auxiliary columns (via QR pivoting) and reports df equal to the realised rank, instead of aborting. White’s test consequently works on models containing factors, where a squared dummy column is collinear with the dummy itself.
• Bug fix: performVIFDiagnostic() now computes variance inflation factors from the inverse correlation matrix of the design, so it works for models with factor predictors (it previously built auxiliary formulas from contrast-expanded column names that do not exist in the model frame, e.g. cyl6, and errored).
• ht_data_cleaning_suggestions() now flags infinite values found in the supplied data, not only those mentioned in the error message.
• Bug fixes surfaced by R CMD check: corrected invalid namespace qualifications (stats::all.vars, stats::summary, utils::close are base functions), fixed a suggestRemediation() call in generateDiagnosticReport() that passed unsupported arguments, and declared the (guarded) optional mgcv dependency.
• Data sets boston_housing, diagnostic_data and hetero_data are now shipped as .rda files (generated by scripts under data-raw/) rather than R scripts, removing the LazyData note and making the bundled data reproducible.
• Testing: the suite is consolidated onto a single test-*.R naming convention, pins Config/testthat/edition: 3, drops the deprecated context() calls, removes three stale top-level-skip()ped files that provided no coverage, and adds behavioural regression tests for the fixes above.

0.6.4

• Added “Comprehensive Guide to Heteroscedasticity Testing” and “Troubleshooting Common Issues” vignettes.
• Implemented performWhiteTestStreaming for large datasets.
• Added wild bootstrap, HC covariance, quantile regression, permutation, high-dimensional, and spatial heteroscedasticity diagnostics.
• Integrated broom tidiers, ggplot2 theming/autoplot support, tidymodels workflows, survey designs, grouped data pipelines, and data.table/dtplyr compatibility for diagnostic workflows.
• Introduced an intelligent recommendation engine that profiles datasets, interprets diagnostics with confidence levels, and delivers remediation guidance plus decision-tree style reports for non-statisticians.
• Implemented robust error handling with adaptive fallbacks, actionable cleaning suggestions, and configurable logging for complex diagnostic workflows.

0.6.3

• Added automated report generation via generateDiagnosticReport.

0.6.2

• Added studentized Breusch-Pagan, bootstrap White and Szroeter tests.

0.6.1

• Introduced TestFactory R6 class with metadata support.
• Added exported test_factory instance registering core tests.
• DESCRIPTION now lists R6 in Suggests.