announce 6.1

_posts/2024-07-01-pomp-version-5.10.md

@@ -6,7 +6,7 @@ title: pomp version 5.10 released
 **pomp** version 5.10 has been released to CRAN and will soon appear on [CRAN mirrors everywhere](https://cran.r-project.org/mirrors.html).
 This release contains a change to the `onestep` rprocess simulator and some minor documentation improvements.
 
-## User-visible change
+### User-visible change
 
 Suppose `P` is a 'pomp' object, with an rprocess component specified as `onestep(f)`, where `f` is a C snippet or **R** function.
 Suppose also that `t==time(P,t0=TRUE)`.

_posts/2025-01-08-pomp-version-6.1.md

@@ -0,0 +1,46 @@
+---
+layout: pomp
+title: pomp version 6.1 released
+---
+
+**pomp** version 6.1 has been released to CRAN and will soon appear on [a mirror near you](https://cran.r-project.org/mirrors.html).
+This release contains breaking changes as well as some additional features.
+
+### User-visible changes
+
+#### New interface for `userdata` becomes mandatory
+
+Since version 5.8.4, the manner in which provides extra elements to basic model components (i.e., beyond parameters, latent state variables, covariates, time, and observations, that is the so-called [`userdata`](https://kingaa.github.io/manuals/pomp/html/userdata.html) are supplied has changed. 
+During a grace period, the old method still worked, though it generated a warning.
+In versions 6.X, an error will be generated.
+To supply additional elements to the basic model components, pass them as elements of a named list via the `userdata` argument, which can be furnished to any [elementary algorithm](https://kingaa.github.io/manuals/pomp/html/elementary_algorithms.html) or [estimation algorithm](https://kingaa.github.io/manuals/pomp/html/estimation_algorithms.html), and of course, to the [pomp constructor](https://kingaa.github.io/manuals/pomp/html/pomp.html) itself.
+
+#### Passing arguments by position now results in an error in most cases
+
+In calls to `pomp` elementary and inference algorithms, it is now necessary to pass arguments *by name* and not by position.
+This has always been good practice, but from this release, calls that rely on the position of arguments will typically generate errors.
+
+### Feature enhancements
+
+#### Initial value parameters in `mif2`
+
+It is now possible to specify more than one lag in the `ivp` function, which is evaluated only when the `mif2` perturbations are specified.
+See `?mif2`.
+
+#### Keeping a database of explorations
+
+In conducting an extensive exploration of a likelihood surface, it is useful to maintain a database of places visited, together with associated likelihood values.
+The new function [`append_data`](https://kingaa.github.io/manuals/pomp/html/bake.html#:~:text=append_data) assists in this.
+It simply appends a given data frame to an existing CSV file (creating the file if it does not exist).
+
+#### Expectation of an Euler-multinomial random variable
+
+The new function [`eeulermultinom`](https://kingaa.github.io/manuals/pomp/html/eulermultinom.html#:~:text=eeulermultinom) gives the expectation of an Euler-multinomial random variable.
+There is also an interface to this function in the [C API](C_API.html#expectation-of-an-euler-multinomial-random-variable).
+
+### Other changes
+
+The `save.states` option to `pfilter` has changed.
+See [`pfilter`](https://kingaa.github.io/manuals/pomp/html/pfilter.html) and [`saved_states`](https://kingaa.github.io/manuals/pomp/html/saved_states.html) for details.
+The deprecated options will still work for the present, but will generate a warning, with advice about how to change.
+Ultimately, these options will be removed.