What’s a sequence?
A sequence is a table that is generated by enumerating all possible values that match a certain pattern. The pattern can be any regular expression (as long as it does not match an infinite number of strings), e.g. "[0-9]" would return ten rows with the numbers 0...9, and "[0-9][A-Z]" would return 10x26 = 260 rows, the first of which would be "0A" and the last of which would be "9Z". One interesting use of sequences is to quickly generate 'mock' data. Read more
Where do I go in the UI to manipulate data in a field? (possibly data cleaning or other transformations)
You can modify field values by editing the data table (double click a value and start typing). Warp will try to find some logic in your edit (e.g. if you make a value uppercase, Warp will assume you need all values in the column to be uppercased). If you want to edit a single value (and save that edit to the source table), click the 'pen' button in the toolbar (after selecting the table you want to edit). Warp will then enter 'edit' mode. Edit mode works for database-backed tables. If you have added a calculation step that modifies the table structure in such a way that Warp cannot identify anymore which row you are editing (e.g. an aggregation), then editing will not be possible either.
How can I take columns from related files to create a new output table?
In order to 'join' two data sets together, drag both to the Warp workspace. Then, find the 'circle' in the right-top corner of one of the tables, and drag from there to the other table. This will create a join between the tables. Select the join step in order to edit its properties. As the join is 'added' on one of the tables, this table 'becomes' the output table.
What do the three buttons at the center of the menubar do?
The 'pen' button tells Warp to enter 'edit mode' - any change you make to the dataset is made permanently in the source data. When not in edit mode, Warp will ask you if you want the change to be permanent, or whether you want to add a calculation step based on the change.
The 'speed' button tells Warp to perform its calculations using all source data. By default, Warp will show you an 'example' outcome based on a (random) sample of the source data. This allows you to work quickly with big data sets, while maintaining a view on what you are doing. If Warp is in 'full data' mode, the button will show a blue 'high speed' icon. Note that any exports you make from Warp are always based on the full data set. (See here)
The 'hand' button can be used to cancel long-running calculations.
All of the buttons apply to the selected table.
What does crawling do?
Crawling loops over each row and fetches a web page for each row. The URL can be defined using a formula based on the row's contents. You may for instance use this together with the sequencer to scrape a website. Read more