Data Set incorporating other data sets by reference?
Author: swuzy
Creation Date: 7/12/2010 12:19 AM
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swuzy

#1
WL 4X data sets could be built up by incorporating other named data sets by reference. I found this extremely convenient as then I only had to update the core data sets and then then can have multiple recombinant versions without having to update the symbols in every one of the derivative sets.

For example, I had core data sets for:

D30 S100 S400 S500 S600 N100 Barrons 400 HXI 173 ADR 392 R1000 R2000 R3000 IBD 100 (current weeks, prior weeks, etc) Salmons (upstream swimmers)

Then I would have many many more derivative data sets combining various of the above. I just have to do a major update twice a year for most of the core data sets, and once a week for the IBD Current set. Now however by way of example, if I have 5 derivatives by adding IBD to say S500, B400, N100, H173, A392, instead of just updating one IBD data set, I have to update 5 data sets (SI, BI, NI, HI, AI), et cetera.

Am I mistaken, or is there still a shortcut way to incorporate data sets by reference? I seem not to have figured out how to do so.

Thanks for clarifying this, and perhaps simplifying my life.
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Cone

#2
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swuzy

#3
Wow. Wonderful. Much needed and very grateful.
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swuzy

#4
It seems the new derivative data sets are created by Aronow by bulk copying individual symbols from the core sets.

Very likely then, the problem remains on subsequent updates of the core data sets, that the derivative data sets will not be automatically updated with deletions and additions in the symbol set.

The Aronow add in makes it easier to bulk copy symbols without "copying and pasting," but does not seem to have the resulting functionality of derivative data sets automatically incorporating revisions of deletions and additions to the core data sets that WL4 provided by simply allowing derivative data sets to be created by dropping in names of core or other data sets.

Hopefully, later versions of WL will restore that very capable functionality.
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Eugene

#5
The "derivative DataSets" contain just links to the original data items. They're initialized when creating a WatchList and aren't so smart to do something automatically. When in need to reflect for a change to the original data source, you should re-create the WatchList.
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swuzy

#6
My misunderstanding then.

I thought the WL4 version, since allowing incorporating other data sets by only referencing the other data sets' names, did not link to the original data items individually, but only linked to the referenced name sets and then processed or initiated them ad hoc, as is, at the time of processing using the named sets as subsequently updated with deletions and additions (thereby in affect "automatically updated" or "automatically" using the reconstituted symbol set). I was hoping that is how WL4 data manager worked (but maybe that is not correct), and hoping for a similar option in WL5.

I can see however that such a method can result in substantially increased processing time, as multiple referenced datasets will have duplicative symbols, whereas individual datasets eliminate duplicative symbols.

I was also hoping that in accessing the referenced symbol sets, a good data manager would do a comparative stripping and skip over duplicative symbols.

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swuzy

#7
I just discovered that the Aronow add in does not take kindly to combining datasets with duplicative symbols. For example, if I wanted a derivative dataset combining S500, B400, N100, it would choke, give me a list of duplicative symbols, and I will have to exit out of the process.

So it is still the manual copy and paste method of multiple datasets for me, whenever a core data set has to be revised (e.g., the weekly IBD 100).
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Eugene

#8
It's not the AronowSoftware addin's fault altogether. Duplicate symbols can't (and shouldn't) exist in a DataSet by design.