Today

• This Thursday’s (2/24) lab will be on Zoom. Mitchell will hold Q&A session on homework 3. You can send questions beforehand so he can be better prepared.

• HW3 (database, Shiny) Q&A.

  • “Pass through” capability of dbplyr (https://db.rstudio.com/advanced/translation/#unknown-functions). Date-related functions in BigQuery: https://cloud.google.com/bigquery/docs/reference/standard-sql/date_functions.

  • collect before saving the local rds file.

  • Error message: Invalid field name "50893". Fields must contain only letters, numbers, and underscores, start with a letter or underscore, and be at most 300 characters long. [invalid]. BigQuery doesn’t like field/variable/column name starting with a number. Check the names_prefix argument of the pivot_wider function.

• Cluster computing using Hoffman2.

• Neural network introduction.