[Solved]-How to properly get data from a d3.js nested array-d3.js

My understanding is that if you're using a CSV or a TSV file your data needs to be in a format like this:

category,date,frequency
shopping,23/7/90,9
shopping,28/7/90,9
shopping,27/7/90,9
shopping,23/8/90,9
shopping,23/9/90,9

As opposed to this:

category,date,frequency shopping,23/7/90,9
category,date,frequency shopping,28/7/90,9
category,date,frequency shopping,27/7/90,9
category,date,frequency shopping,23/8/90,9
category,date,frequency shopping,23/9/90,9

Once in the correct format, you can then you can reference the data after you import the CSV as d.category, d.date, etc.

Here is a good example of a great multi-series line chart using a TSV: https://bl.ocks.org/mbostock/3884955