P_sequence questions (boundaries etc..)

[Elisa Kagan (HUJI)]

Dear Christopher,
I am working on C14 ages from paleoseismological outcrops. I have
amassed a few questions after working intensely on this. Some
questions are more technical-trivial, some more code-related.


1. I can’t get the title to appear on the output diagram (I tried
going to Format-Plot-Title (check), I also tried to insert a title in
the “Format-Adjust-Title” box. No luck.
2. On the output diagram the x-axis always has numbers like 1 AD, 101
AD, 501 AD, 1001 AD, instead of 1,100, 500, or 1000….. how can I get
rid of this?
3. I want to have the outliers presented on the graph for purpose of
showing all data, however not taken into account in the model, is this
possible and how?
4. I am doing a P_sequence deposition model of C14 ages in a
paleoseismological outcrop. I would like to have an internal boundary
that completely separates two periods, which have a gap (not
necessarily known exactly the length of the gap) between them.
Basically we need two models from different periods but presented on
the same age-depth diagram. How can I enter this kind of boundary into
the code?
5. Does just entering a boundary in the middle allow change in
deposition rate?

Thank you very much, Elisa

[Christopher Ramsey]

Thanks for your message. I'll try to address them.

On 17 Nov 2008, at 11:16, Elisa Kagan (HUJI) wrote:

>
> Dear Christopher,
> I am working on C14 ages from paleoseismological outcrops. I have
> amassed a few questions after working intensely on this. Some
> questions are more technical-trivial, some more code-related.
>
>
> 1. I can’t get the title to appear on the output diagram (I tried
> going to Format-Plot-Title (check), I also tried to insert a title in
> the “Format-Adjust-Title” box. No luck.

No this only applies to individual plots - multiple plots are not
given titles - I could add this if people thought it useful.

>
> 2. On the output diagram the x-axis always has numbers like 1 AD, 101
> AD, 501 AD, 1001 AD, instead of 1,100, 500, or 1000….. how can I get
> rid of this?

This only applies when the dates span BC and AD - the problem is that
200 years after 100 BC is 101 AD - and so if the ticks on the axis are
evenly spaced you cannot avoid this problem. If you choose the 'Date
reporting' format +-CE (ISO-8601 yrs) you will get around this as it
will use -100 and +100 - this is because in the ISO-8901 standard
there is a year zero. You get the same if you choose Gregorian
fractional years which work on the same basis.

>
> 3. I want to have the outliers presented on the graph for purpose of
> showing all data, however not taken into account in the model, is this
> possible and how?

I have not yet implemented this - the outlier detection is only at the
beta-testing stage at the moment anyway. I can see that this would be
useful - I will try to include this in the release version 4.1

>
> 4. I am doing a P_sequence deposition model of C14 ages in a
> paleoseismological outcrop. I would like to have an internal boundary
> that completely separates two periods, which have a gap (not
> necessarily known exactly the length of the gap) between them.
> Basically we need two models from different periods but presented on
> the same age-depth diagram. How can I enter this kind of boundary into
> the code?

You can either put two P_Sequences together with a Sequence - to
ensure that the start of one comes after the other as in:

Sequence()
{
P_Sequence(){...};
P_Sequence(){...};
};

or you can just put two boundaries at the point of the possible gap
(the depths will have to be at least slightly different). The latter
method does make different assumptions as it is does assume the
overall deposition is part of one process - the method suggested above
treats the two deposition sequences entirely separately except for one
constraint. It would probably be a good test of robustness to try both.

>
> 5. Does just entering a boundary in the middle allow change in
> deposition rate?

yes that is right - which is why putting in two Boundaries allows a
hiatus/gap.

Christopher

[Laurens Thissen]

> On 17 Nov 2008, at 11:16, Elisa Kagan (HUJI) wrote:
>
>>

>> 1. I can’t get the title to appear on the output diagram (I tried
>> going to Format-Plot-Title (check), I also tried to insert a title in
>> the “Format-Adjust-Title” box. No luck.
>
> No this only applies to individual plots - multiple plots are not
> given titles - I could add this if people thought it useful.
>>

Hi Christopher,

Although very belated, I would appreciate it if multiple plots could
be given titles. They can of course be added on the svg output by hand
in, e.g., inkscape, but that is an extra step.

Talking about output appearances - would it be possible also to add a
tickable option enabling automatic adding of the BP date following the
sample number? (R_Date OxA-xxxx)? I thought this very useful in the
older OxCal versions.

Thanks,

Laurens Thissen

THISSEN
ARCHAEOLOGICAL
CERAMICS
BUREAU

[Christopher Ramsey]

Laurens

I have included both of these things in the new version (v4.1).

If you add a title in the [Format > Adjust] tab on a multiplot this
will appear just above the top of the plot.

You can also select the option to plot parameters on the [Format >
Plot] tab which will show all radiocarbon dates even if you have date
labels.

Thank you for the feedback.

Christopher