As a minor release, R 3.6.2 makes only small improvements to R, including some new options for dot charts and better handling of missing values when using running medians as a smoother on charts. It also includes several bug fixes and performance improvements.
But big changes are coming to R with version 4.0.0, which is expected to be released not long after R's official 20th birthday on February 29, 2020. (The CelebRation 2020 conference will mark the occasion in Copenhagen.) The R Core team has announced previews of some of the changes, which include:
An enhanced reference counting system. When you delete an object in R, it will usually releases the associated memory back to the operating system. Likewise, if you copy an object with
y <- x, R won't allocate new memory for
x is later modified. In current versions of R, however, that system breaks down if there are more than 2 references to any block of memory. Starting with R 4.0.0, all references will be counted, and so R should reclaim as much memory as possible, reducing R's overall memory footprint. This will have no impact on how you write R code, but this change make R run faster, especially on systems with limited memory and with slow storage systems.
Normalization of matrix and array types. Conceptually, a matrix is just a 2-dimensional array. But current versions of R handle matrix and 2-D array objects differently in some cases. In R 4.0.0, matrix objects will formally inherit from the array class, eliminating such inconsistencies.
A refreshed color palette for charts. The base graphics palette for current versions of R (shown as R3 below) features saturated colors that vary considerably in brightness (for example, yellow doesn't display as prominently as red). In R 4.0.0, the palette R4 below will be used, with colors of consistent luminance that are easier to distinguish, especially for viewers with color deficiencies. Additional palettes will make it easy to make base graphics charts that match the color scheme of ggplot2 and other graphics systems.
Many other smaller changes are in the works too. See the NEWS file for the upcoming R release for details.
R developer page: NEWS file for upcoming R release