Information for prodrate.m (version 201912) calibrating reference 10Be and 26Al production rates.
The calculator is fixed by Jakob Heyman (jakob.heyman@gu.se) 2015-2019 mainly based on the CRONUS
calculator (Balco et al. 2008) and the LSD production rate scaling (Lifton et al. 2014).


TO USE THE CALCULATOR:
1. Fix the input.txt file (see below).
2. Run prodrate.m in Octave (Matlab might work as well).
3. Reference 10Be and/or 26Al production rates (atoms/g/yr) are saved in out-prodrate.txt.


The calculator is based on the CRONUS calculator (Balco et al. 2008) with some modifications:
* Nuclide-specific time-dependent LSD spallation production rate scaling based on simulated cosmic
  ray fluxes (Lifton et al. 2014).
* Time-constant muon production rate parameterization (modified to reduce near-surface artifacts),
  including depth dependence for samples with an assumed erosion rate, based on Antarctica depth
  profile data (Borchers et al. 2016; Marrero et al. 2016; Phillips et al. 2016; Balco 2017) with
  fstar and sigma0 calibrated using muclib.m.
* Adjustment of the time-dependent production rate to the year of sampling (assuming a constant
  production since 2010).
* Atmospheric pressure based on sample elevation and ERA-40 re-analysis dataset ('std'), Antarctica
  best-fit interpolation ('ant') (Balco et al. 2008), or given directly ('pre') in hPa.
* Attenuation length for calculating the spallation production rate adjustments for sample thickness
  and erosion rate interpolated from atmospheric pressure and cutoff rigidity (Marrero et al. 2016).
* Sample group reference production rate and uncertainty based on weighted average using the
  "expected value method" (Birch and Singh 2014).
* The calibration age uncertainty, which is not an independent variable for each sample of a
  calibration site, is added in quadrature to the sample group reference production rate (and to
  each sample reference production rate uncertainty).
* If Pcluster = 1 (line 18), outliers are removed in an attempt to achieve a well-clustered
  reference production rate. Parameters for this (lines 21-23) are minimum number of well-clustered
  samples, maximum outlier ratio of full group size, and p-value limit for clustering test.


INPUT INSTRUCTIONS:
The input is given in the file input.txt and the format can be one of two options. For both options
the data for each sample is specified in one row (rows can be commented out with '%').

Option 1:
Similar input as for the CRONUS exposure age calcuator version 2, with changed unit for erosion rate
and the addition of sampling year, calibration age, and calibration age uncertainty. The input
should contain 18 columns with the following information:
1. Sample name - (strange characters may cause problems).
2. Latitude [DD (WGS84)] - North latitudes are positive. South latitudes are negative.
3. Longitude [DD (WGS84)] - East longitudes are positive. West longitudes are negative.
4. Elevation/pressure [m a.s.l. / hPa].
5. Elevation/pressure flag - std/ant/pre (ERA40 elev interpol/Antarctica elev/atmospheric pressure).
6. Sample thickness [cm].
7. Sample density [g/cm3].
8. Correction factor - Unitless factor used for topo/geom shielding correction (no shielding -> 1).
9. Erosion rate [mm/ka]. NOTE: different unit than in the CRONUS calculator.
10. 10Be concentration [atoms/g] - (if no 10Be measurement: use 0).
11. 10Be concentration uncertainty [atoms/g] - (if no 10Be measurement: use 0).
12. 10Be standardization - See make_consts_expage.m lines 34-38 for acceptable names and values.
13. 26Al concentration [atoms/g] - (if no 26Al measurement: use 0).
14. 26Al concentration uncertainty [atoms/g] - (if no 26Al measurement: use 0).
15. 26Al standardization - See make_consts_expage.m lines 41-42 for acceptable names and values.
16. Sampling year [CE].
17. Calibration age [yr before sampling] - Independently known exposure age.
18. Calibration age uncertainty [yr].

Option 2:
Data in columns with row 1 specifying the data of each columns. The following specifiers are
allowed (the order of the data/columns is irrelevant):
sample - Sample name - (strange characters may cause problems).
lat - Latitude [DD (WGS84)] - North latitudes are positive. South latitudes are negative.
long - Longitude [DD (WGS84)] - East longitudes are positive. West longitudes are negative.
elv - Elevation/pressure [m a.s.l. / hPa].
Pflag - Elevation/pressure flag - std/ant/pre (see above). If not specified std will be used.
thick - Sample thickness [cm].
dens - Sample density [g/cm3].
shield - Correction factor - Unitless factor used for topo/geom shielding correction.
erosion - Erosion rate [mm/ka]. If not specified a zero erosion rate is assumed.
N10 - 10Be concentration [atoms/g].
N10unc - 10Be concentration uncertainty [atoms/g].
std10 - 10Be standardization - See make_consts_expage.m lines 34-38 for acceptable names and values.
N26 - 26Al concentration [atoms/g].
N26unc - 26Al concentration uncertainty [atoms/g].
std26 - 26Al standardization - See make_consts_expage.m lines 41-42 for acceptable names and values.
samplingyr - Sampling year [CE].
calage - Calibration age [yr before sampling] - Independently known exposure age.
calageunc - Calibration age uncertainty [yr].
pressure - Atmospheric pressure [hPa] - If pressure is included, data in elv is not used.
isostP - String specifying the isostatic adjustment method for atmospheric pressure adjustments.
isostsubm - String specifying the isostatic adjustment method for submergence adjustments.
For both isostP and isostsubm, the following strings can be used:
ICE6G - Isostatic adjustment using the global ICE6G data (Argus et al. 2014; Peltier et al. 2015).
ANU2017 - Isostatic adjustment using the data from Lambeck et al. (2017) for North America.
PD2015 - Isostatic adjustment using the Påsse and Daniels (2015) data for Fennoscandia.
filename - Name of file with isostatic adjustment data (tv, delv or shoreline, and yr0).
If a sample has the string '-' for isostP or isostsubm, no isostatic adjustment is carried out.


OUTPUT INFORMATION:
The calculator saves reference 10Be/26Al production rates in the file out-prodrate.txt. The
reference production rate (atoms/g/yr) with uncertainty (including calibration age uncertainty) is
saved for each sample. If Pcluster = 1 (line 18), sample production rates included in the site
production rates are marked with X. Following the individual sample production rates, the individual
site production rate data is saved with site name, site reference production rate, site reference
production rate uncertainty, reduced chi square value, and P-value. If Pcluster = 1 (line 18), site
production rates fulfilling the cluster criteria (lines 21-23) are marked with X.

If there is only one 10Be or 26Al measurement the output will only contain the individual sample
production rate (no group production rate and statistics).

Samples with 0/0 concentration/uncertainty yield '-' in the output.
If all input 10Be concentration/uncertainty are 0/0 no 10Be data is saved.
If all input 26Al concentration/uncertainty are 0/0 no 26Al data is saved.

The calculator plots (line 17) individual sample proabability density curves (red lines), a summed
probability density curve (black line) for the reference production rates, individual outlier
density curves (blue lines), and the group reference production rate (vertical black line) and
uncertainty (grey area). Note that the probability density curves do not include the calibration age
uncertainty but the group production rate uncertainty (grey area) does include the calibration age
uncertainty.
