Changes in DENSITY 5.0.3, April 2014
In Density 5.0.3 a bug was fixed
that could cause some points to be dropped from the computation mesh.
The effect on estimates is expected to be minimal.
Changes in DENSITY 5.0, December 2012
A new tool button on the main form starts an interface to the R package secr.
This translates the current data entry, data filters and model
specification into R code. The code is optionally submitted
to R in batch mode, and results are displayed in DENSITY.
Many rarely-used, incomplete or deprecated features have been removed. These include
The default capture format has changed from XY to TrapID.
The PowerAnalysis module has been renamed Simulator, and this is more fully documented.
The Animals and Pxy contour toolbuttons on the main form use parameter
values from a panel displayed whenever they are called, instead of
values from Options | IP SECR.
- A Monte Carlo test for non-independence of trap-revealed locations has been reinstated from a previous version of DENSITY.
Various popup menus and selectors on the main form have been tweaked or relocated for better performance.
Capture details for a selected animal or point are displayed in a
floating window rather than a panel at the bottom right of the main
Cycling over animals may be interrupted by clicking on the map.
- The main form displays the current buffered area ('Mesh') on the status bar even when no mask is in use.
- Mesh points further than the buffer distance from any trap are now discarded by default (see Options | Computation Trap buffer).
- IP SECR and the ShowAnimals tool button now respect habitat defined with an imported mesh
- ML SECR now reports the expected population size in the masked area (MLEN).
- ML SECR automatically transfers estimates to Tools | ML SECR log likelihood.
- 'z' notation is used throughout for shape parameter of hazard-rate detection function in preference to 'b' or 'hazz'.
- DISTANCE interface (see Distance web page)
- Binomial N-mixture and Double-observer N estimation (see R package unmarked)
- Artificial cover objects
- Area live and Area kill detector types (see polygon detector type in R package secr)
- Windows priority setting (use the Windows Task Manager Ctrl-Alt-Del)
TIP: If you absolutely need any of these you can find an old version of DENSITY at www.otago.ac.nz/density.
- SE of derived (Horvitz-Thompson) estimate of density misreported (lacked encounter-rate component)
- Options | Output field selector not working
- In the simulator, resampling of a capture file failed with a numeric error
- In Data | Import | Capture histories removals miscoded for occasions before last
- Some memory leaks have been fixed so 'Out of memory' problems are less likely
- ML SECR could fail with conditional likelihood and
between-session models when number of animals detected declined
- Occasion, trap and individual covariates were standardised
using the within-session mean and SD, which could be misleading in
- 'Simulate one sample' ShowAnimals tool button popup option was not working
- Minor interface malfunctions: 'One occasion at a time' map
display did not apply to selected animal; 'Traps as dots' not
working with proximity detectors; ML contour P(wi|X) did not scroll
with animal selector.
The program has been ported from Borland Delphi 6 to a much more recent version of the Object Pascal compiler, Delphi XE2.