I put a quarterly series in a Basket, converted it to annual, and downloaded it, but the "native frequency" header still reads "quarterly." Why?
Data Buffet basket output includes several header fields for each time series, one of which is native frequency. This is the frequency of the series before you (optionally) apply a frequency conversion. There is no header field for the subsequent (converted) frequency; instead, examine the period labels (dates) running alongside the observations.
Example 1:
You pick forecast time series FET.US, which is quarterly. You run and download the basket as a Microsoft Excel file. In the output file, the native frequency field reads as "QUARTERLY" and the period labels read as "2012Q1, 2012Q1, 2012Q3," etc. These are quarterly dates.
(Because Excel has no cell format for quarterly dates, these basket period labels are strings.)
Example 2:
You pick FET.US again, but in the basket editor, you convert its frequency to annual. In the output file, the native frequency field still reads as "QUARTERLY" and the period labels read as "Dec-2011, Dec-2012, Dec-2013," etc. These are annual dates.
(For Excel-type basket output the period labels are (usually) dates, and for annual dates, we designate the year using December 31, e.g., "12/31/2012." The default cell formatting shows them as "Dec-{year}" (custom formatting code "mmm-yyyy"), but you can change this inside Excel.)
Background:
Every time series stored in Data Buffet has a native frequency -- daily, monthly, annually, etc. When you pick a series, you can download it verbatim, or change it: apply a frequency conversion, analytic transformation, or formula. In doing so, you have created a synthetic series.
Basket header fields are optional, and you can enable/disable them in the basket editor under the Options » Fields panel. The default output file type is Microsoft Excel 5.0, but you can pick others from Options » File; some file types have an immutable set of header fields. Your basket will contain at least one sequence of period labels; if you mix several frequencies, you will get labels for each; optionally, you can display period labels with every series, using the Options » Dates panel.