There are two ways to find a dataset in ERDDAP.
Data fileTypes |
Description | Info | Example |
---|---|---|---|
.asc | View OPeNDAP-style comma-separated ASCII text. | info | example |
.csv | Download a comma-separated ASCII text table (line 1: names; line 2: units; ISO 8601 times). | info | example |
.csvp | Download a .csv file with line 1: name (units). Times are ISO 8601 strings. | info | example |
.csv0 | Download a .csv file without column names or units. Times are ISO 8601 strings. | info | example |
.das | View the dataset's metadata via an OPeNDAP Dataset Attribute Structure (DAS). | info | example |
.dds | View the dataset's structure via an OPeNDAP Dataset Descriptor Structure (DDS). | info | example |
.dods | OPeNDAP clients use this to download the data in the DODS binary format. | info | example |
.esriCsv | Download a .csv file for ESRI's ArcGIS 9.x and below (separate date and time columns). | info | example |
.fgdc | View the dataset's FGDC .xml metadata. | info | example |
.geoJson | Download longitude,latitude,otherColumns data as a GeoJSON .json file. | info | example |
.graph | View a Make A Graph web page. | info | example |
.help | View a web page with a description of tabledap. | info | example |
.html | View an OPeNDAP-style HTML Data Access Form. | info | example |
.htmlTable | View a .html web page with the data in a table. Times are ISO 8601 strings. | info | example |
.iso19115 | View the dataset's ISO 19115-2/19139 .xml metadata. | info | example |
.itx | Download an Igor Text File. Each response column becomes a wave. | info | example |
.json | View a table-like JSON file (missing value = 'null'; times are ISO 8601 strings). | info | example |
.mat | Download a MATLAB binary file. | info | example |
.nc | Download a flat, table-like, NetCDF-3 binary file with COARDS/CF/ACDD metadata. | info | example |
.ncHeader | View the header (the metadata) for the .nc file. | info | example |
.ncCF | Download a NetCDF-3 CF Discrete Sampling Geometries file (Contiguous Ragged Array). | info | example |
.ncCFHeader | View the header (the metadata) for the .ncCF file. | info | example |
.ncCFMA | Download a NetCDF-3 CF Discrete Sampling Geometries file (Multidimensional Array). | info | example |
.ncCFMAHeader | View the header (the metadata) for the .ncCFMA file. | info | example |
.odvTxt | Download longitude,latitude,time,otherColumns as an ODV Generic Spreadsheet File (.txt). | info | example |
.subset | View an HTML form which uses faceted search to simplify picking subsets of the data. | info | example |
.tsv | Download a tab-separated ASCII text table (line 1: names; line 2: units; ISO 8601 times). | info | example |
.tsvp | Download a .tsv file with line 1: name (units). Times are ISO 8601 strings. | info | example |
.tsv0 | Download a .tsv file without column names or units. Times are ISO 8601 strings. | info | example |
.xhtml | View an XHTML (XML) file with the data in a table. Times are ISO 8601 strings. | info | example |
Python is a widely-used computer language that is very popular among scientists.
In addition to the Pydap Client, you can use Python to download various files from ERDDAP
as you would download other files from the web:
import urllib urllib.urlretrieveOr download the content to an object instead of a file:
("http://baseurl/erddap/tabledap/datasetID.fileType?query",
"outputFileName")
import urllib2 response = urllib2.open
("http://baseurl/erddap/tabledap/datasetID.fileType?query")
theContent = response.read()
APDRC example in Python tutorial page.
MATLAB .mat - Matlab users can use tabledap's .mat file type to download data from within
MATLAB. Here is a one line example:
load(The data will be in a MATLAB structure. The structure's name will be the datasetID
urlwrite('http://apdrc.soest.hawaii.edu/erddap/tabledap/
argo_all.mat?longitude%2Clatitude%2Ctime%2Cpres%2Ctemp
&time%3E=1998-09-01&time%3C=1998-09-02',
'test.mat'));
ERDDAP stores datetime values in .mat files as "seconds since 1970-01-01T00:00:00Z".
To display one of these values as a String in Matlab, you can use, e.g.,
unique_time = unique(argo_all.time);
datestr(unique_time(1)/86400 + 719529)
ans =
01-Sep-1998 04:21:35
86400 converts ERDDAP's "seconds since" to Matlab's "days since". 719529 converts
ERDDAP's base time of "1970-01-01T00:00:00Z" to Matlab's "0000-01-00T00:00:00Z".
You can then make a plot of pressure vs. temperature on Sep 1, 1998. For example:
time1_i = find([argo_all.time] == unique_time(1));
plot(argo_all.temp(time1_i),argo_all.pres(time1_i))
set(gca,'YDir','Reverse')
APDRC example in MATLAB tutorial page.