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.
Also,
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The default capture format has changed from XY to TrapID.
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The PowerAnalysis module has been renamed Simulator, and this is more fully documented.
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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
form.
-
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'.
Many rarely-used, incomplete or deprecated features have been removed. These include
- 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.
Bugs fixed:
- 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
over time
- Occasion, trap and individual covariates were standardised
using the within-session mean and SD, which could be misleading in
multi-session models
- '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.