Make A Graph

Dataset Title:	Average Alexandrium catenella occurrence risk (25-48h)
Institution:	DFO-MPO (Dataset ID: mpoAlguesToxiquesPred25-48)
Information:	Summary \| License \| FGDC \| ISO 19115 \| Metadata \| Background \| Data Access Form \| Files

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Graph Type:
X Axis:
Y Axis:
Color:

Dimensions

Start

Stop

time (UTC)

specify just 1 value →

latitude (degrees_north)

longitude (degrees_east)

Graph Settings
Color Bar:	Continuity:	Scale:
Minimum:	Maximum:	N Sections:
Draw land mask:
Y Axis Minimum:	Maximum:

(Please be patient. It may take a while to get the data.)

Optional:
Then set the File Type: (File Type information)
and

or view the URL:
(Documentation / Bypass this form

)

Click on the map to specify a new center point.

Zoom:

[The graph you specified. Please be patient.]

Things You Can Do With Your Graphs

Well, you can do anything you want with your graphs, of course. But some things you might not have considered are:

Web page authors can embed a graph of the latest data in a web page using HTML <img> tags.
Anyone can use ERDDAPs Slide Sorter to build a personal web page that displays graphs with the latest data (or other images or HTML content), each in its own, draggable slide.

The Dataset Attribute Structure (.das) for this Dataset

Attributes {
  time {
    String _CoordinateAxisType "Time";
    Float64 actual_range 1.6771356e+9, 1.6796592e+9;
    String axis "T";
    String calendar "gregorian";
    String ioos_category "Time";
    String long_name "Time";
    String standard_name "time";
    String time_origin "01-JAN-1970 00:00:00";
    String units "seconds since 1970-01-01T00:00:00Z";
  }
  latitude {
    String _CoordinateAxisType "Lat";
    Float64 actual_range 43.007623748779295, 54.297623748779294;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Latitude";
    String standard_name "latitude";
    String units "degrees_north";
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float64 actual_range -78.17900573730469, -37.719005737304684;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String standard_name "longitude";
    String units "degrees_east";
  }
  Risk {
    Float32 _FillValue -3.4e+38;
    String grid_mapping "crs";
    String long_name "A.catenella occurrence risk (0-100)";
    Float64 max 2.736972489693706;
    Float64 min 0.0037976342549134153;
    String proj4 "+proj=longlat +datum=NAD83 +no_defs";
  }
  NC_GLOBAL {
    String Algae_model "HARM v1";
    String cdm_data_type "Grid";
    String Climate_model "CIOPS-E v1.2";
    String Conventions "CF-1.6, COARDS, ACDD-1.3";
    String created_by "R, packages ncdf4 and raster (version 3.5-15)";
    String creator_name "DFO-MPO";
    String creator_type "institution";
    String date "2023-03-24 21:04:06";
    String Description "Daily forecast of Alexandrium catenella occurrence risk (0-100 scale) in the Estuary and Gulf of St. Lawrence averaged between 25-48h after forecast time";
    Float64 Easternmost_Easting -37.719005737304684;
    String Forecast_time "2023-03-24 08:00:00";
    Float64 geospatial_lat_max 54.297623748779294;
    Float64 geospatial_lat_min 43.007623748779295;
    Float64 geospatial_lat_resolution 0.009999999999999998;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max -37.719005737304684;
    Float64 geospatial_lon_min -78.17900573730469;
    Float64 geospatial_lon_resolution 0.010000000000000002;
    String geospatial_lon_units "degrees_east";
    String history 
"2023-03-25T04:08:12Z (local files)
2023-03-25T04:08:12Z https://erddap.ogsl.ca/griddap/mpoAlguesToxiquesPred25-48.das";
    String infoUrl "???";
    String Institution "DFO-MPO";
    String institution "DFO-MPO";
    String keywords "0-100, 25-48h, 48h, a.catenella, alexandrium, average, catenella, data, department, dfo, dfo-mpo, fisheries, latitude, longitude, mpo, occurrence, ocean, oceans, risk, time";
    String license "Open Government Licence - Canada, Licence du gouvernement ouvert - Canada";
    Float64 Northernmost_Northing 54.297623748779294;
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing 43.007623748779295;
    String standard_name_vocabulary "CF Standard Name Table v70";
    String summary "Daily forecast of Alexandrium catenella occurrence risk (0-100 scale) in the Estuary and Gulf of St. Lawrence averaged between 25-48h after forecast time";
    String testOutOfDate "now-19days";
    String time_coverage_end "2023-03-24T12:00:00Z";
    String time_coverage_start "2023-02-23T07:00:00Z";
    String Timelapse_covered "25-48h average from Forecast time";
    String title "Average Alexandrium catenella occurrence risk (25-48h)";
    Float64 Westernmost_Easting -78.17900573730469;
  }
}

Using griddap to Request Data and Graphs from Gridded Datasets

griddap lets you request a data subset, graph, or map from a gridded dataset (for example, sea surface temperature data from a satellite), via a specially formed URL. griddap uses the OPeNDAP (external link)

Data Access Protocol (DAP) (external link)

and its projection constraints (external link)

The URL specifies what you want: the dataset, a description of the graph or the subset of the data, and the file type for the response.

(easy) You can get data by using the dataset's Data Access Form. It makes the URL for you.
(easy) You can make a graph or map by using the dataset's Make A Graph form. It makes the URL for you.
(not hard) You can bypass the forms and get the data or make a graph or map by generating the URL by hand or with a computer program or script.

griddap request URLs must be in the form
https://coastwatch.pfeg.noaa.gov/erddap/griddap/datasetID.fileType{?query}
For example,
https://coastwatch.pfeg.noaa.gov/erddap/griddap/jplMURSST41.htmlTable?analysed_sst[(2002-06-01T09:00:00Z)][(-89.99):1000:(89.99)][(-179.99):1000:(180.0)]
Thus, the query is often a data variable name (e.g., analysed_sst), followed by [(start):stride:(stop)] (or a shorter variation of that) for each of the variable's dimensions (for example, [time][latitude][longitude]).

For details, see the griddap Documentation.