READ ME (Please!):
Probabilistic - Cosmogenic_Age_Analysis_Tool Executable
Kentucky Geologic Survey
, University of Kentucky, Lexington, Kentucky
February 14, 2020
Cosmogenic Age Analysis Tool (CAAT) isolates skewness from chronology datasets by separating Gaussians from probability density to estimate even age.
The CAAT application was develop in the MATLAB environment and is compiled for standalone application without the need to purchasing MATLAB.
- If you do not have a copy of MATLAB, a prompt will appear to download MATLAB Runtime, which is ~ 1GB in size.
- A prompt about installing an application from an unknown publisher will likely appear. You must click yes to continue with installation.
CAAT was developed in the MATLAB environment to isolate skewness from cosmogenic and cosmogenically calibrated Schmidt hammer exposure ages. It utilizes the ksdensity function and bandwidth estimators to calculate a probability density estimate from chronology data. Component Gaussians are isolated using the nlinfit algorithm based on a Monte Carlo style approach.
A .csv or .txt file with four columns:
Column 1 = a consistent label grouping all ages from a single landform
Column 2 = Age in ka
Column 3 = Internal uncertainty in ka
Column 4 = External uncertainty in ka
Quick Start Instructions
- Load a file
- Select a dataset
- Select a bandwidth estimator
- Calculate results
There are three bandwidth choices on the selection knob:
- Mean – uses the arithmetic mean of the internal age uncertainties
- STD/IQR – uses Silverman's (1986) "rule of thumb"; a common bandwidth estimator
- MAD – uses a variation of Silverman's (1986) "rule of thumb" where mean absolute deviation is substituted for STD/IQR
See Dortch et al. (in review) for details and discussion on bandwidth behavior with sample size.
NL Data button: Select this button when analyzing regional data, in the ~10-500 ka age range, to separate out correlative regional events. Regional data are a compilation landform ages (component Gaussian peak and sigma) under a single label. Regional data in ~0-1 ka and ~1-10 ka groupings should be run normally without using the ‘LN Button'. Regional analysis should not be used not for combining individual TCN ages from several landforms into one data pool.
Examining Plots: All plots have options appear when hovering the mouse. This include zoom, pan, restore original extent, and export. Use the 'Save as type' drop down in file explorer to save your preferred file type. Id saving 'Figure 1: Main data plot', it is strongly suggested to stretch the figure vertically to the height of your screen as having four subplots significantly compresses the vertical axis.
To generate a publication style plot:
- Identify the component Gaussian that best fits an event from the plots or tables and enter the Component Gaussian number in the box and hit enter. This will highlight all of the ages that fall within two sigma propagate external uncertainty of the selected component Gaussian.
- If analyzing regional data, landform ages instead of individual TCN ages, enter a capitol ‘R' without the quotes. This will propagate external uncertainty for all component Gaussians in attrition to converting natural log data back into linear age.
- Use the ‘Plot color' slider to choose weather highlights are in red or black to suit print or online publication.
Save Table Results: This button saves the model fitment data and the component Gaussian data as .csv files.
Stay safe and have fun!
P-CAAT: Probablistic – Cosmogenic Age Analysis Tool
- Read in full before installing the P-CAAT application.
By installing or using the Probabilistic Cosmogonic Age Analysis Tool (P-CAAT) and clicking next, you explicitly agree to all terms in this statement. If you do not agree, do not install or use the P-CAAT application and select cancel instead.
License: You are granted revocable, non-exclusive, non-transferable, limited license to download, install and use the P-CAAT application solely for non-commercial personal academic purposes strictly in accordance with the terms of this Agreement.
Restrictions: You agree not to, and will not permit others to: license, sell, rent, lease, assign, distribute, transmit, host, outsource, disclose or otherwise commercially exploit the P-CAAT application.
By installing P-CAAT, you waive any rights to hold the Authors, their employers, and their institutions liable for: damage to your equipment, misuse, or poor interpretations resulting from the installation or use of the P-CAAT application. This includes, but is not limited to, if you or your institutions computer(s)/network(s) is corrupted, resets, dies, melts, explodes, catches fire, shorts out, acts weird or buggy, interferes with other programs/applications, disappears into the ether, and/or kills your dreams, prevents you from obtaining an academic degree, or makes you so smart you can no longer relate to others and feel isolated/depressed.
We reserve the right to modify, suspend (temporarily or permanently), or otherwise modify P-CAAT and subsequent versions without any liability to you.
P-CAAT is dedicated to Jason's cat "Anorthite"
who passed in June 2019. Anorthite inspired Jason to routinely ponder on Dr. Schrödinger's ideas and probabilistic approaches to both science and life.