New in Distance

New Features of Distance 7.0 Release 1

We have added a few new features as well as making a number of bug fixes after a long test period in the beta phase.

  • Main interface
    • Distance 7.0 Release 1 will register itself to open .dst files when you double-click on them.
    • Removed links to R package pdfs, these can now be accessed via the package websites on CRAN
    • Some modifications to Distance Preferences
  • Distance Users Manual
    • Updates to cover the new features
  • Simulation Engine
    • The simulation engine can now run with designs (multiple surveys) rather than just a single survey set of transects.
    • Point transects are now implemented in addition to line transects.
    • Uses R package DSsim version 1.0.8 (compiled with R 3.3.1)
  • MRDS Engine
    • R package mrds updated to 2.1.17 (compiled with R 3.3.1)
    • Some changes and bug fixes – see NEWS file of R package mrds
  • DSM Engine
    • R package dsm updated to 2.2.13 (compiled with R 3.3.1)
    • Some changes and bug fixes – see NEWS file of R package dsm
  • Multi-Analysis Engine
    • Uses R package mads version 0.1.4 (compiled with R 3.3.1)
    • Minor changes and bug fixes – see NEWS file of R package mads

New Features of Distance 7.0 Beta

No new features have been added. However D7B3 has been used in our August 2015 international training workshop and has had a number of bug fixes repaired.

  • Setup for D7B3 now ships with following R package versions
    • DSsim 1.0.4
    • dsm 2.2.9
    • mrds 2.1.14-2
    • mads 0.1.3-2

New Features of Distance 7.0 Alpha

Distance 7 features two major additions, the Simulation engine and the Multi-Analysis (MA) engine.

  • Simulation Engine
    • A simulation capability has been added.
    • Uses R package DSsim version 1.0.3 (compiled with R 3.1.2)
  • MRDS Engine
    • R package mrds updated to 2.1.13 (compiled with R 3.1.2)
    • Multiple other changes and bug fixes – see NEWS file of R package mrds
  • DSM Engine
    • R package dsm updated to 2.2.5 (compiled with R 3.1.1)
    • For other changes to the R package, see NEWS file of R package dsm
  • Multi-Analysis Engine
    • The multi-analysis (MA) engine had been added to the analysis options in Distance
    • Uses R package mads version 0.1.2 (compiled with R 3.1.2)

New features in Distance 6.2

Multiple bug fixes and minor enhancements, as summarized below

  • CDS/MCDS Engine:
    1. An important bug that meant variance estimates for point transects were incorrect has been fixed - please re-run all point transect analyses from Distance 6.0 and 6.1.
    2. Other minor improvements in output labeling.
  • MRDS Engine:
    1. R package mrds updated to 2.1.5 (compiled with R 3.1.0).
    2. Multiple other changes and bug fixes – see NEWS file of R package mrds.
    3. Monotonicity checks now performed in ds models.
    4. Left truncation for exact and interval data now possible in interface.
  • DSM Engine:
    1. R package dsm updated to 2.2.3 (compiled with R 3.1.0).
    2. Some added features: autocorrelation plots, gam.check (and rqgam.check) fitting diagnostics.
    3. For other changes to the R package, see NEWS file of R package dsm.
    4. Some minor changes to properties pages used to specify models, and to the results details titles.

New features in Distance 6.0

  • New Analysis Capabilities:
    • New analysis engine: density surface modeling (DSM).
    • New variance estimators for CDS, MCDS and MRDS.
  • Other Improvements:
    • Changes made to location of default settings database and sample projects, to enable Distance to work better under default Microsoft Vista security settings.
    • Ability to open projects by dragging and dropping project files onto an empty part of the main project window.
    • Improved documentation and more sample projects.
    • Improvements to MRDS plotting functions.
    • Better link with R software: obsolete objects are deleted from the R Folder and .RData by default.
    • Muliple bug fixes and minor enhancements (in Distance, choose Help | Release notes for a comprehensive list).

New features in Distance 5.0

  • New Analysis Capabilities**
    • Interface with the free statistics software R (note - R is not included within the download file - it must be downloaded and installed separately for the new analysis engine (below) to function. R is not required for any other part of the program to function.)
    • New analysis engine: Mark-recapture distance sampling (MRDS). Allows analysis of dual observer distance sampling surveys, where probability of detection on the trackline can be estimated. Currently restricted to line transects. 
  • Other Improvements
    • Better bootstrapping in the CDS and MCDS engine: progress is given on the main toolbar; bootstrap point estimates are given in the output and analysis browser columns (useful for model averaging – see Model averaging in CDS Analysis).
    • Better documentation (e.g., MCDS engine command reference in an appendix) and many more sample projects.

New Features in Distance 4.1

  • New Analysis Capabilities
    • Better goodness-of-fit testing – q-q plots, K-S tests and Cramer-von Mises statistics for exact data in both CDS and MCDS engines
    • When calculating adjustment terms, you can now scale distance by either truncation distance w or estimated scale parameter σ. 
    • When combining stratum estimates to form a global density estimate, if you weight by effort you can now treat the effort strata as either fixed or random effects.
  • Graphical User Interface
    • GIS has improved capabilities for coping with projections: the list of candidate projections is much longer and you can now specify projection parameters.

New Features in Distance 4.0

  • Survey Design
    • Ability to enter study area details into built-in GIS
    • Can then examine properties of user-specified designs, from a wide range of different design classes (e.g., random points, grid of points, line segments, zig-zag lines, etc)
    • Can generate survey plans for the different designs.
  • New Analysis Capabilities
    • New MCDS engine allows multiple covariates in the detection function
    • Data selection function of the Data Filter now much more powerful.
    • For surveys with nested sample layers (e.g., clusters of points along a line), the user can choose which level to treat as the independent sample for determining encounter rate variance.
    • Analysis engines now calculate AICc, as well as other model selection measures
  • Graphical User Interface
    • Built-in GIS, based on MapObjects by ESRI (compatible with ArcView)
    • Data Explorer and Analysis Browser consolidated into the Project Browser.  New tabs for Designs, Surveys and Maps added.
    • New Analysis Components window makes it easier to keep track of Data Filter and Model Definitions.
    • Lots of small refinements, e.g. Data Filter and Model Definition properties remember which tab they were last on, making setting up analyses quicker; naming objects is now easier – double click on the names in the Project Browser, or in the Details windows to edit them.
  • Data Storage
    • Much more flexible data structure – data can be linked from external databases in a variety of formats (although there is no user interface for this yet – has to be done by direct editing of the database).
    • Internal data now stored in DistData.mdb file within separate data folder.  The data folder is also used by default to store the GIS information (ESRI shapefiles).  Distance 4 project is therefore a project file (.dst file) and the associated project folder.
    • More layer types, including coverage probability, nested strata and effort layers, etc.  Can now have unlimited number of data layers in the project
    • New survey object multiple surveys to be stored together in the same project file, but analyzed separately.  Surveys can have different survey methods and different units.
  • New Utilities
    • Data import now more flexible – can import one or more data layers, and can use ID or Label fields to link to the parent layer.  Various limitations in previous version caused by MS database engine not correctly recognizing the data types of text fields has been worked around.