In this note, I explore some recent changes in the open-source R package dbplyr to illustrate some of the beauty of how open-source software evolves in practice. In particular, I offer two case studies where features requested by users became reality in dbplyr, which may be my favourite R package.

Plot of feasible return parameters with portfolios of two risky assets

Plot of feasible portfolio returns given two risky assets by correlation

R code to replicate examples from [here](https://wrds-web.wharton.upenn.edu/wrds/support/Accessing%20and%20Manipulating%20the%20Data/_007R%20Programming/_001Using%20R%20with%20WRDS.cfm).

House prices over time

Test