Difference between revisions of "MaxEnt"

Revision as of 10:59, 16 October 2014

Description

This page explains how to use the MaxEnt Algorithm on the Statistical Manager with the i-Marine portal.. The algorithm is hosted by the D4ScienceAn e-Infrastructure operated by the D4Science.org initiative. e-InfrastructureAn operational combination of digital technologies (hardware and software), resources (data and services), communications (protocols, access rights and networks), and the people and organizational structures needed to support research efforts and collaboration in the large. that supports i-Marine. It is a Maximum-Entropy model for species habitat modeling, based on the implementation by Shapire et al. v 3.3.3k at Princeton University.

In this adaptation the software accepts a table following the Species Product Discovery service model of i-Marine and a set of environmental layers in various formats (NetCDF, WFSWeb Feature Service, WCSWeb Coverage Service, ASC, GeoTiff) via direct links or GeoExplorer UUIDs.

The user can also set the bounding box and the spatial resolution (in decimal degrees) of the training and the projection. The application will adapt the layers to that resolution if this is higher than the native one.

The output is made up of the following components:

• a thumbnail map of the projected model,
• the ROC curve,
• the Omission/Commission chart,
• a table containing the raw assigned values,
• a threshold to transform the table into a 0-1 probability distribution,
• a report of the importance of the used layers in the model,
• ASCII representations of the input layers to check their alignment.

Starting from this output, other processes of the Statistical Manager can be later applied to the raw values, for example to produce a GIS map (e.g. the "Statistical Manager Points to Map" process). Eventually, results can be shared with other participants to the e-InfrastructureAn operational combination of digital technologies (hardware and software), resources (data and services), communications (protocols, access rights and networks), and the people and organizational structures needed to support research efforts and collaboration in the large. using the i-Marine workspace.

Demo Video

Here is a demonstration of the usage of the MaxEnt algorithm on the Statistical Manager: http://goo.gl/TYYnTO

Feeding the algorithm with Inputs Maps

In the layers box users can insert links to maps that will be used to associate environmental values to species occurrence records. The + button allows to insert a new layer.

Input Map Examples

Input from GeoExplorer

using the i-Marine GeoExplorer application:

• search for an environmental layer (e.g. temperature)
• click on one of the layers found by the search
• in the "Summary Layer Info" panel on the right scroll down and select the Metadata UUID string (e.g. cd048cb5-dbb6-414b-a3b9-1f3ac512fbff)
• paste the UUID in the layers box in MaxEnt

Input from a WFSWeb Feature Service link

MaxEnt can import WFSWeb Feature Service links residing either on a GeoServer or on a MapServer. The server must be able to produce maps details in json format. In this case you can insert the direct WFSWeb Feature Service link in the layers box, without specifying the bounding box.

E.g.: http://geoserver-dev.d4science-ii.research-infrastructures.eu/geoserver/ows?service=wfs&version=1.0.0&request=GetFeature&srsName=urn:x-ogc:def:crs:EPSG:4326&TYPENAME=aquamaps:worldborders

Please, use EPSG:4326 as projection.

Input from a WCSWeb Coverage Service link

You can input a direct WCSWeb Coverage Service link.

E.g.:

http://geoserver-dev.d4science-ii.research-infrastructures.eu/geoserver/wcs/wcs?service=wcs&version=1.0.0&request=GetCoverage&coverage=aquamaps:WorldClimBio2&CRS=EPSG:4326&RESPONSE_CRS=EPSG:4326

Please, use EPSG:4326 as projection.

Input from a NetCDF-GRID file

You can input the OpenDAP link to a NetCDF file, only if this contains one single dimension layer.

E.g.:

http://thredds.research-infrastructures.eu/thredds/dodsC/public/netcdf/WOA2005TemperatureAnnual_CLIMATOLOGY_METEOROLOGY_ATMOSPHERE_.nc

ASC ESRI-GRID files

You can input a direct http link to an ESRI-GRID file, even using local common publishing tools (e.g. dropbox).

E.g.:

http://thredds.research-infrastructures.eu/thredds/fileServer/public/netcdf/ph.asc

https://dl.dropboxusercontent.com/u/12809149/layer1.asc

GeoTiffs

Http links to GeoTiff files are allowed, even using local common publishing tools (e.g. dropbox). E.g.:

https://dl.dropboxusercontent.com/u/12809149/wind1.tif

Contacts

For questions and bug alerts use this form.