Check that a detection function is monotone
Check that a fitted detection function is monotone non-increasing.
check.mono( df, strict = TRUE, n.pts = 100, tolerance = 1e-06, plot = FALSE, max.plots = 6 )
df |
a fitted detection function object |
strict |
if |
n.pts |
number of equally-spaced points between left and right truncation at which to evaluate the detection function (default 100) |
tolerance |
numerical tolerance for monotonicity checks (default 1e-6) |
plot |
plot a diagnostic highlighting the non-monotonic areas (default FALSE) |
max.plots |
when |
Evaluates a series of points over the range of the detection function (left to right truncation) then determines:
1. If the detection function is always less than or equal to its value at the left truncation (g(x)<=g(left), or usually g(x)<=g(0)).
2. (Optionally) The detection function is always monotone decreasing (g(x[i])<=g(x[i-1])). This check is only performed when strict=TRUE (the default).
3. The detection function is never less than 0 (g(x)>=0).
4. The detection function is never greater than 1 (g(x)<=1).
For models with covariates in the scale parameter of the detection function is evaluated at all observed covariate combinations.
Currently covariates in the shape parameter are not supported.
TRUE if the detection function is monotone, FALSE if it's not. warnings are issued to warn the user that the function is non-monotonic.
David L. Miller
Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.