This describes the SUBSET indicator in ShareFinder 5, which permits a share graph to be limited to a range of dates, for historical or back-testing purposes.
 |
The SUBSET indicator is an internal facility and is not officially intended for client use. Consequently there is no guarantee as to its performance or suitability for any specific task, nor that it will be retained in future versions of ShareFinder. Use of the information that follows is at your own risk. |
How to use the SUBSET indicator
The SUBSET indicator does not appear in any of ShareFinder's indicator lists. It is only available by using the Advanced Query editor.
Create a new blank graph. You do this by clicking the Analyse menu,
then "New Graph Window". From the share list that appears, choose a
share, DIDATA for example, then click the "Advanced" button to bring up
the advanced trace editor. In this example, the initial query will be:
didata.
Add the SUBSET indicator to the query by typing \subset
followed by a comma and the range of dates you want. A typical range
might be:
didata\subset,20020101-20021231
In the above example, ShareFinder will limit the graph range from 1 January to 31 December 2002. Dates are written in the format YYYYMMDD, with no punctuation except a hyphen between the two.
You can omit either of the two dates. For example:
subset,20020101- returns data from 1 January 2002 to the end of the database. The last hyphen is optional.
subset,-20021231 returns data from the beginning up to 31 December 2002. The hyphen is significant.
Instead of absolute dates, you can specify the number of days that you want. For example:
subset,200- returns the last 200 trading days (not calendar days). The last hyphen is optional.
subset,-200 returns the first 200 trading days in the database. The hyphen is significant.
Finally you can have a combination of dates and numbers of days. For example:
subset,20020101-200 returns 200 trading days beginning with 1 January 2002.
subset,200-20021231 returns 200 trading days ending with 31 December 2002.
If you enter an invalid date, type something unexpected or omit something that is required, it will produce a blank graph. The query interpreter is not very forgiving, but you can go back and edit the query until it is correct. Pay special attention to the punctuation characters and the date format.
Back-testing with the SUBSET indicator
The obvious use of SUBSET is for back-testing, to compare
ShareFinder's latest analysis with one from a few days or weeks ago. A
query such as subset,-20030430 for example will produce a
graph as it would have appeared on 30 April 2003.
Up to now we have worked only on a new graph window, but SUBSET can also be applied to the standard graph display of price, volume, Mass and Velocity. Open the graph that is of interest (let's use DIDATA again) and press F2 to open the Graph Setup panel.
Double-click the share name so that it brings up the share list, then click the "Advanced" button to get to the advanced trace editor. Now you can apply the subset indicator as shown above. When you click OK, the graph will be redrawn with the date range you ask for, with the Mass and Velocity indicators changing to match.
When you edit a standard graph in this way, ShareFinder removes the outlook message. This is because the outlook message is designed only to interpret the standard graph configuration. You can interpret the graph yourself using the very rough principle that if Mass and Velocity are both at the bottom and turning up, it is a "buy" situation. Conversely if both are at the top and turning down, it is a "sell" situation. All the other messages fit between those two extremes.
