button or simply
by clicking on the example file icon in this manual.
In addition to the information here you should now be in a position to make
sense of the commands given in the section on
`Archaeological Considerations'
and you should also be able to call up the
example run files either using
the button or simply
by clicking on the example file icon in this manual.
Within multi-plots or other groups dates can be offset using the Offset command. For example a carved piece of wood thought to be 60+-10 years old at the time of felling might have been radiocarbon dated. A probability distribution for its felling date would then be given by the two commands:
R_Date 980 50; Offset 60 10;Note that the offset is positive to produce a later probability distribution.
Luminescence dates are another type of chronological information that can be entered. Assuming you are not simply entering them as calendar ages, the year of measurement, dose rate and error in the dose rate must be entered. Instead of entering the calendar ages you can then enter the sample estimated doses (prefixed by `d'). For example:
Plot
{
Year 1994;
Dose 2.0e-3;
Error 5%;
C_Date d1.0 d0.2;
C_Date d1.1 d0.2;
C_Date d1.3 d0.2;
};
In this case the first date will be calculated from the dose rate to
be 500+-100 years before 1994 and then an additional error of 5% added in.
The error is always given in terms of a percentage as above or as a
proportion (as in Error 0.05;).
If the error is defined within a combination
(Combine)
it will not be applied until after the combination has been performed.
R_Simulate -500 60;In this case you will find that the errors associated with the radiocarbon dates are always large. Every time you recalculate this you will get a different radiocarbon date (with a similar distribution to the measurements you would expect to get).
See also [Archaeological Considerations]
See also [Archaeological Considerations]
Note that groups or related events (coming from one period) should be enclosed with boundaries. The 'Auto Boundary' feature of the program is designed to help with this. When you add a phase or a model the program asks whether the group is a well defined separate group (rather than being just a part of a larger group). If you answer yes the phase or sequence will be bracketted by boundaries.
Within sequences termini ante quem and termini post quem can be defined using TAQ and TPQ.
The special case of `wiggle-matching' is covered by the defined sequence command (D_Sequence). In such a group each item must be separated by a Gap command giving the separation between the measured samples. The same calculation can also be performed in a slightly different way using Combine (see D_Sequence). The similar case of sequences where the gap is only know approximately is covered by the variable sequence command (V_Sequence) within which each item must be separated by a gap with an error term.
It is also possible to put extra constraints on a date by referring to it in more than one place using the command XReference. Consider the example from `Archaeological Considerations':
Sequence
{
R_Date "A" 900 30;
R_Date "B" 830 60;
};
Sequence
{
R_Date "C" 940 60;
TPQ
{
XReference "A";
};
R_Date "D" 890 70;
};
Here: A must be before B and D; B must be after A; C must be before D;
D must be after A and C.NOTE: that cross references can be conveniently entered using the Windows interface by holding down the [Ctrl] key and dragging from the cross reference to the new position.
See also [Archaeological Considerations]
So as an example where they have all been requested one might have:
Sequence
{
R_Date "K" 2760 60;
Interval "I";
Phase "1"
{
First "B";
R_Date "L" 2700 50;
R_Date "M" 2800 60;
Last "E";
Span "S";
};
R_Date "N" 2670 60;
R_Date "O" 2660 60;
Difference "D" "N" "K";
};
In this example the distributions B and E will be plotted with the
distributions for K, L, M, N and O which are produced by the analysis.
Distributions I (which gives the interval between K and the first item
in phase 1), S (which gives the span of phase 1) and D (the time between
K and N) will all be plotted on a separate page of the analysis output
since they represent age differences rather than absolute ages.
NOTE: that to enter the paramters for
Difference using the Windows
interface you can just hold down the [Ctrl] key and drag the parameters
onto the (expanded) 
icon.
See also Shift.
If you wish to question the presence of a item in a sequence this is done
by ending the command with a `?' instead of a `;' or drag
over the 
icon. This removes the constraints
imposed by the position of this sample in the sequence and tells the
analysis program to calculate the probability that a sample should be
in this position in the sequence (see section on
`Probability and agreement indices'
and Question).
Correlations between two events can be plotted using Correlate this gives plots of like:
After "A" {R_Date 3050 60;};
The main use for such distributions is for use in combinations where you
might wish to add into a probability distribution the fact that the event
must be after or before another.
Order
{
R_Date "A" 1100 50;
R_Date "B" 1000 50;
R_Date "C" 900 50;
};
gives the resultant probabilities:
74.2% A B C 20.4% A C B 5.1% B A C 0.1% B C A 0.1% C A BNote that probabilities below 0.1% are not shown and that a maximum of 50 different orders are reported. There is also a limit of 50 on the number of items that can be ordered in this way.
See also [Archaeological Considerations]