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Matching sample in Tucson format to reference curve?

Posted: 05 Mar 2010, 19:33
by Lars-Ake
I have just purchased the CDendro program. All my files are in the decadel Tucson format. When I try to match a sample to a reference curve, it appears that the sample must be in the coordinate (.pos)format. If so, how can I use my Tucson-formatted samples in this procedure?
Open your Tucson-file with the menu command "Collections/Create new collection from ...."
That will open your collection consisting usually of several members.
When you double-click on any of the members it will open in a new separate "sample-window".
That "sample-window" can be crossdated towards another sample window which you have selected as your reference.

There are other ways to get such a sample-window: You can open e.g. a .pos file or a .wid file.

You may also use a somewhat obsolete menu command Samples/Select from decadal ...file to open only a few samples selected from e.g. an .rwl/Tucson file, though I never use that way. Yes - it may be reasonable to do it when you have only one member within your Tucson file.

To get a reference or mean value out of a collection (e.g. a Tucson .rwl file with many members) use the button "Create mean value sample" when you have opened your collection with "Create new collection from..." Remember to use the button "Select as reference" in that opened sample-window when there was already another sample selected as the reference..

Hope that will get you started!

Re: Matching sample in Tucson format to reference curve?

Posted: 05 Mar 2010, 19:56
by Lars-Ake
Thank you for the support, I was able to perform the function.. It has been extremely useful! I am still learning the program.

I have two related questions. First, once such a sample is cross dated, can the file be saved into a Tucson format with the correct years? Also, if the curve has been adjusted for missing years (i.e. with right click), can the adjusted curve be saved in Tucson format with the missing year added as a zero value?

Finally, I downloaded the help files, but I cannot access them through the help menus. Rather I have to open them separately. Can you advise me on how to fix this.
I'll try to answer...
When a sample is crossdated you can settle the date (the year number) within the "sample-window" itself by clicking the "Set date of youngest Ring/Dated to xx" button on the Workbench tab. Then problem is to save the file....- you can save it in e.g. .wid format. This is a common way to work.
But you may then add it to an empty collection at offset 0 and then write out that single-member collection in e.g. .rwl format

If the dated sample-window was created from a member of a collection of several members, you may prefer to update the offset of the member within the collection, and later write out the collection in e.g. .rwl format
To change the offset, right-click on the member of the collection.
Another way might be to add that newly dated sample to your collection as a replacement of the original undated member, though in that case you first have to write out your sample as .e.g. a .wid-file which you later do not need when you have written out your collection as a .rwl file. - You do not have to remember to first save your sample in a .wid-file. If you try to add data of a changed "sample-window" to a collection, CDendro will alert you about the need of first saving your data.

Remember that there are two main ways to store collections, either as .rwl, .fh, .txt files containing all the data.
OR as a .fil file which is only a list of pointers to files containing the ring width data. You can inspect any collection file with your text editor to see how the data is stored.

On inserted zero values:
If you have inserted zero values, you have to save the file in e.g. .wid format (like you had to do when you had changed the dating) before you add it to a collection which you can then write out in e.g. .rwl format.

After you have fiddled with offsets within a collection or added new members, it is always a good procedure to run the command (a button) "Test towards rest of collection". That will show you if one or more members do not crossdate properly. When doing this for a collection of only different radii from the SAME stem, you first have to uncheck the "Sum by stem" checkbox. Though if you forget this, CDendro might hint you about it.

On accessing the installed help, see this: