Win-Vector LLC is proud to introduce two important new tool families (with documentation) in the 0.5.0 version of seplyr (also now available on CRAN):

• partition_mutate_se() / partition_mutate_qt(): these are query planners/optimizers that work over dplyr::mutate() assignments. When using big-data systems through R (such as PostgreSQL or Apache Spark) these planners can make your code faster and sequence steps to avoid critical issues (the complementary problems of too long in-mutate dependence chains, of too many mutate steps, and incidental bugs; all explained in the linked tutorials).
• if_else_device(): provides a dplyr::mutate() based simulation of per-row conditional blocks (including conditional assignment). This allows powerful imperative code (such as often seen in porting from SAS) to be directly and legibly translated into performant dplyr::mutate() data flow code that works on Spark (via Sparklyr) and databases.

Image by Jeff Kubina from Columbia, Maryland – [1], CC BY-SA 2.0, Link

For “big data in R” users these two function families (plus the included support functions and examples) are simple, yet game changing. These tools were developed by Win-Vector LLC to fill gaps identified by Win-Vector and our partners when standing-up production scale R plus Apache Spark projects.

We are happy to share these tools as open source, and very interested in consulting with your teams on developing R/Spark solutions (including porting existing SAS code). For more information please reach out to Win-Vector.

To teams get started we are supplying the following initial documentation, discussion, and examples:

• Mutate Partitioner package vignette
• if_else_device reference
• “Partition Mutate” article
• “Partitioning Mutate, Example 2” (includes if_else_device) article.