NEWS

---

tweedie 2026-05-20

Summary

Minor fixes and improvements

Changed

• Added details input to dtweedie_series(), that returns the lo and hi index for the summing of terms. Other necessary changes made downstream.
• Added (tweedie_integrand(), tweedie_profile()) and improved (tweedie_plot()) the passing of plotting parameters.

Fixed

• Fixed tweedie_integrand: Plot 2 now plots cos( Im k(t) ) for the PDF (not sin).

tweedie 2026-04-26

Summary

Minor fixes and improvements

Changed

• Improvements to tweedie_plot() and passing plotting options

Fixed

• Fix error with accelerate when returning early: return properly(Thanks Jeonghwan Lee)

tweedie 2026-02-26

Changes:

• Fixed an error with xi = 1 and phi \ne 1 in qtweedie (thanks Milan Bouchet-Valat).
• Added a test to prevent this again.
• Relocated hex.R and fixed the hex-producing script.
• Fix Makefile.

tweedie 2026-02-16

Changes:

• Improved the vignette.
• Some internal renaming.
• Fix some xi = 1 cases (thanks Milan Bouchet-Valat).
• Relocate some messages in tweedie_profile().
• Add poison example to vignette.

tweedie 2026-02-07

Changes:

• Trying to fix bugs that pop up (seemingly at random) with rhub etc. checks.

tweedie 2026-01-30

Changes:

• FORTRAN code restructured to make the similar flow in the three zones (initial; pre-acceleration; acceleration) clearer
• Some fixes to documentation to pass tests.
• Some minor fixes to R code.

tweedie 2026-01-20

Changes:

• Some fixes to implementation of IGexact

tweedie 2025-11-29

Changes:

• Add IGexact for [dp]tweedie_inversion: whether to use exact values or inversion when p = 3.
• Fixed some comments

Changes:

• All code moved from FORTRAN77 to FORTRAN90. Almost no FORTRAN code remains from version < 3.
• PDF and CDF computations consolidated and code shared where possible, substantially reducing the amount of FORTRAN code.
• Separated FORTRAN code into different files for easier debugging.
• Improvements to the acceleration algorithm and root-finding algorithms, so should work better for more cases.
• Added verbose (shows what's happening behind the scenes) and details (reports on the fitting) as options for many user-facing R functions.
• Added ptweedie_inversion() to the man page for dtweedie.
• Tidied the man pages; added examples.
• Removed the almost-never used dtweedie.stable() function.
• Changed function names (e.g, tweedie.convert() to tweedie_convert()).
• Separated R functions into separate files depending on purpose (e.g., dtweedie.R and ptweedie.R).
• Moved the tweedie_Extra files into the main package.
• dtweedie.igrand() (now tweedie_igrand()) to plot the integrand for the DF also.

tweedie 2022-08-17

Changes:

• Added outputs gamma.mean and gamma.phi to tweedie.convert()
• Added more error checks to tweedie.convert() to prevent a model being provided
• Minor edits

tweedie 2017-11-15

Changes:

• Updated ptweedie.series() to fix a bug (reported by Lu Yang), where incorrect answers could sometimes be returned.
• Other minor fixes

tweedie 2017-11-06

Changes:

• Fixed an issue with AICtweedie(), where the incorrect AIC was given when prior weights used (reported by David Scollnik)
• Fixed a compilation error (in the subroutine smallp(), where variables were declared as initialised (thanks to Iñaki Úcar [email protected])
• Other minor edits.

tweedie 2017-08-23

Changes:

• Kept it even more quiet

tweedie 2017-08-22

Changes:

• Fixed tweedie.f() to keep it quiet more often (sometimes, diagnostic reports meant for internal monitoring, were printed)
• Fixed a problem reported by Gustavo Lacerda, where ptweedie() returned NaN
• As a result, the series is now used in far more cases when 1<xi<2 for ptweedie()
• Changed rtweedie() algorithm for the case 1 < xi < 2 (thanks to Carlos J. Gil Bellosta)
• New function tweedie.convert() added

tweedie 2016-12-19

Changes:

• Added CITATION file
• Fixed an issue where the Tweedie cdf could return a value greater than one (reported by Jeremie Juste)
• Minor tidy of FORTRAN code
• Minor tidies in R code

tweedie 2014-06-06

Changes:

• Some administrative fixes for CRAN

tweedie 2013-09-10

Changes:

• Fixed an issue where ptweedie() would fail for very small y; set this to 0 when y<1.0e-300 (based on a report by Johann Cuenin)

tweedie 2013-01-15

Changes:

• Admin release (e.g. .First.lib() removed)
• Some minor edits to manual
• Added the control input to tweedie.profile() (thanks to Giri Khageswor, DPI Victoria)
• Minor fixes in the manual

tweedie 2012-11-01

Changes:

• Changed the example in tweedie-package to execute faster (CRAN requirement)

tweedie 2012-10-31

Changes:

• Fixed an error in dtweedie() that reported NA in the case when power=1 and phi != 1 (thanks to Dina Farkas)
• [dqpr]stable now in package stabledist rather then fBasics; fixed
• Fixed some typos in the help for tweedie-package (thanks to Peng Yu)
• rtweedie() reported an error if power = 1; fixed (thanks for Peng Yu)
• Edits to conform with new first argument of .Fortran (i.e. .NAME rather than name)
• Added NAMESPACE

tweedie 2011-06-09

Changes:

• Changed tweedie.profile() to ignore values of p/xi outside (1, 2) rather than report an error.
• In some unusual cases, when p/xi = 0 was used (with add0 = TRUE), the mle of p was between 0 and 1 (which is impossible). We report a warning message to check the data and the call to tweedie.profile(), but then set the mle to the value of p/xi giving the larger value of the likelihood
• Made the functions usually called by users able to accept xi or power
• A few minor edits to FORTRAN code; some variables not declared

tweedie 2011-06-08

Changes:

• Minor fixes to documentation
• Fixed the add0 input
• Some minor changes to the code to tidy up adding the zero
• If values of xi/p are given between 0 and 1, or less than 0, they are now omitted (with a message) rather than creating an error. If there are no values left after omitting the problem value, an error message is given.

tweedie 2010-09-30

Changes:

• Ensured tweedie.profile() does not use power = 1. This case (power=1 and phi not equal to 1) is too hard for me to deal with at present.
• Fixed an error introduced in version 2.0.5, where the value of xi.vec/p.vec was set to 1.2 (y >= 0) or 1.5 (y > 0) when not explicitly specified
• Fixed an error that reported the wrong mle of phi when the mle occurred at an endpoint of the given xi values.

tweedie 2010-08-27

Changes:

• Change to dtweedie.inversion() to ensure density = 0 is returned when y < 0 (1 < p < 2) or p <- 0 (when p > 2)
• Change to tweedie.profile() to fix a problem that p = 1 returned an error
• Changed so that tweedie.profile() works with p/xi = 0 when add0=TRUE (default is FALSE)
• Fixed some minor outputting messages (when verbose == 2)
• Location of CITATION file moved to correct location

tweedie 2010-07-12

Changes:

• Minor edits

tweedie 2009-12-18

Changes:

• Changed default p.vec: There were too many values
• Added the facility to refer to p as xi in line with GLMs text

tweedie 2009-11-17

Changes:

• Changed the default p.vec when 1 < p < 2 to seq(1.2, 1.8, by = 0.05) (it was seq(1.2, 1.8, by = 0.1) )
• Slightly changed default output (added sep = "" to some paste commands)
• Added AICtweedie() to compute AIC for Tweedie glms

tweedie 2009-09-19

Changes:

• Corrected specification of GPL; no changes to functionality, code or documentation
• In dtweedie(), added power == 3 (inverse Gaussian) as a special case
• Minor change in documentation
• Added data, weights, and offset input arguments
• Fixed a bug where "=>" was used rather than ">="
• Fixed a bug in tweedie.profile(): exact zeros still allowed p = 2 (but not p > 2)

tweedie 2009-08-10

Changes:

• Made method = "inversion" the default (was "series")
• Slightly changed default output (added sep = "" to some paste commands)
• An error introduced earlier (unsure when exactly; prob v 1.6.1)
• In trying to identify and fix the error, tidied some of the FORTRAN code
• Made do.smooth = TRUE the default (was FALSE)
• If p.vec is not supplied, tweedie.profile() makes a sensible guess
• Made verbose = FALSE the default (was TRUE)
• Made minor changes to output when verbose = FALSE

tweedie 2009-07-18

Changes:

• Correct error in dtweedie.saddle() when y = 0 for 1 < p < 2 (Thanks to Glenn Meyers [email protected])

tweedie 2009-02-16

Changes:

• Fixed a bug in ptweedie.inversion() where variable cdf was undefined
• Fixed a bug in qtweedie() where any(power) < 1 should have been any(power < 1)

tweedie 2009-02-06

Changes:

• Fixed error in tweedie.f() (twice) where a float was used in a do-loop
• Fixed a bug in ptweedie(): It now returns 0 when y < 0 (rather than reporting an error)
• Fixed a bug in ptweedie.inversion(): y.len was undefined
• Fixed a bug in dtweedie.inversion(): if( any(phi < 0) ) written as if (any(phi) < 0 )
• Built for R version 2.6.0
• Changed the tweedie.plot() to produce no default x and y labels

tweedie 2007-09-01

Changes:

• Built for R version 2.5.1
• Removed the inversion computation from the example for dtweedie(); it was very slow and hence caused problems

tweedie 2007-05-03

• Built for R version 2.5.0
• Fixed citation details
• Added note in dtweedie() help page indicating where the methods are defined (Dunn and Smyth, 2007).
• Added tweedie-package.Rd
• Fixed a small bug in dtweedie.inversion() (replaced p with power)
• Built for R version 2.5
• Made change to use of pmatch() in function tweedie()
• Swapped the order of methods 1 and 2 in the call of tweedie.inversion to make consistent with a change in the associated paper Dunn and Smyth.
• Fixed an uninitialized variable error in the FORTRAN code which sometimes caused the inversion procedure to fail.
• Other minor changes (fixing spelling errors, updated Dunn and Smyth reference; etc.)
• Some very minor changes (some cosmetic) in the code
• Made the code more robust, exiting gracefully when Inf and NA appear in the computed log-likelihood
• Slightly changed the output plot in tweedie.profile(), to reflect that some value of p.vec may not have a corresponding likelihood computed accurately (or, indeed, at all)
• Added new function tweedie.plot() to make it easier to plot Tweedie densities

tweedie 2006-09-05

Changes:

• Built for R version 2.0.0
• Major fix: The mle estimate of phi was incorrect in tweedie.profile() (thanks Sarah Lennox, QDPI&F) * Some better warnings in tweedie.profile()
• tweedie.profile() now allows the actual computed points to be added to the plot using the do.points option (default is TRUE)
• The tweedie.profile() function now smooth and computes confidence intervals even when the computed likelihood values contain Infs or NAs.

tweedie 2004-09-30

Changes:

• Built for R version 1.9
• Fixed a bug in rtweedie(): it failed for p = 2 (thanks Sarah Lennox, QDPI&F)
• Fixed a bug in qtweedie(): it failed in some cases (thanks Gordon Smyth, WEHI)
• Added a proper .First.lib function (!) (thanks to James Wettenhall and Gordon Smyth, WEHI)
• Other minor bugs fixed
• The tweedie() family function removed, and package made dependent on the statmod package
• Updated for R version 1.9

tweedie 3.1.1

Summary

Minor fixes and improvements

Changed

• Fixed typo in README.Rmd.

tweedie 1.6.7 (2009-06-30)

Changes:

• Correct error in rtweedie() when power = 1 and phi \ne 1 (Thanks to Frederic Gosselin [email protected])