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distributions/
pl_like.pro
toppl_like
Statistics
result = pl_like( [params] [, derivs] [, data=data] [, alpha=alpha] [, xmin=xmin])
This function calculates the log-likelihood of the data, under a powerlaw model. The powerlaw distribution is given by f(x) = (alpha - 1) (xmin)^(alpha - 1) x^(-alpha)
To maximize speed, the function does not check for values of data < xmin. However, the output is useless when any data are < xmin.
Return value
Ln(Product( f(data_i) ) )
Parameters
- params in optional
A two element vector specifying [alpha, xmin].
- derivs in optional
A named variable to hold the partial derivative of the log-likelihood with respect to alpha and xmin.
Keywords
- data in optional
A vector of data values, assumed to be >= xmin
- alpha in optional
Another way to specify alpha. This takes precedence over any variable stored in params[0].
- xmin in optional
Another way to specify xmin. This takes precedence over any variable stored in params[1].
File attributes
| Modifcation date: | Mon Mar 22 16:17:13 2010 |
| Lines: | 68 |