maplandscape’s Shiny app provides tools for adding new columns to layers in GeoPackages as a function of values in existing columns. This is based on dplyr’s mutate function.
To add a column to a layer in the app scroll down to the Table Analysis section of the side bar and select Add Column under the Select analysis dropdown list.
Choose the layer that you wish to add a column to and click the Add Column Options button.
This will bring up a modal popup window where you can enter the name of the column you wish to create and specify how to compute values in this new column. Standard R and dyplr syntax can be used here. For example,
time_minutes * 60 would convert numeric values representing minutes in a
time_minutes column to a new set of values in seconds.
Depending on whether the result of the
add_column operation was successful or not you will get a success or error notification. You can select the layer that you added a column to in the Select active layer widget to inspect the new column.