Index of /~carterja/code
Name Last modified Size Description
Parent Directory 20-Sep-2009 10:46 -
filterredwv.pro 02-Sep-2009 16:25 1k
minfuncwv.pro 02-Sep-2009 16:25 1k
solveredwv.pro 03-Sep-2009 11:17 5k
waveletlike.pro 02-Sep-2009 16:25 1k
WAVELET-BASED METHOD FOR PARAMETER ESTIMATION; IDL CODE
- For details refer to the paper by Carter & Winn (2009):
Parameter Estimation from Time-Series Data with Correlated Errors:
A Wavelet-Based Method an its Application to Transit Light Curves
- Quick overview of IDL procedures or functions (refer to actual code for implementation
details, calling sequence, examples, etc.):
waveletlike - computes the "wavelet (log) likelihood" for a data vector
with 2^J elements for J a positive integer. The 1/f+white noise
model is parameterized by two parameters (SIGMA_R, SIGMA_W) that are
related to the standard deviation of the two components.
filterredwv - Filters out the 1/f component for a data vector with 2^J elements
for model parameters SIGMA_R and SIGMA_W.
solveredwv - Uses AMOEBA to solve for model parameters SIGMA_R and SIGMA_W given
a data vector with 2^J elements. Also separates 1/f and white components
into two separate output vectors.
minfuncwv - Wrapper function for use with solveredwv. Is not a stand-alone function.
- Adding models for parameter estimation
Our code here only solves for the noise parameters SIGMA_R and SIGMA_W,
however, the tools necessary for parameter estimation with additional models
have been provided.
The function waveletlike can be used to assess the likelihood of a set of residuals
after having removed a guess for any deterministic signal in the data. For
example, a model transit light curve can first be subtracted from light curve data
before calculating log(likelihood) with waveletlike. One may then use standard
estimation techniques to determine noise and transit parameters; e.g., via AMOEBA
minimization of -log(likelihood) or Markov chain Monte Carlo where the likelihood,
calculated as a log in waveletlike, is used as the jump-transition likelihood.
Similarly, filterredwv can be used to "whiten" residuals after having removed
the best fit deterministic signal.
- Revisions
Written, Josh Carter September 2009