Make A Graph

Dataset Title:	Estimated Seafloor Depth Gradients: ETOPO (US West Coast)
Institution:	NOAA ERD (Dataset ID: erdEtopoSeafloorGradient)
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

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 {
  latitude {
    String _CoordinateAxisType "Lat";
    Float32 actual_range 20.0, 50.0;
    String axis "Y";
    String ioos_category "Location";
    String long_name "Latitude";
    String reference_datum "geographical coordinates, WGS84 projection";
    String standard_name "latitude";
    String units "degrees_north";
    Float32 valid_max 50.0;
    Float32 valid_min 20.0;
  }
  longitude {
    String _CoordinateAxisType "Lon";
    Float32 actual_range 230.0, 255.0;
    String axis "X";
    String ioos_category "Location";
    String long_name "Longitude";
    String reference_datum "geographical coordinates, WGS84 projection";
    String standard_name "longitude";
    String units "degrees_east";
    Float32 valid_max 255.0;
    Float32 valid_min 230.0;
  }
  magnitude_gradient {
    Float64 colorBarMaximum 0.05;
    Float64 colorBarMinimum 0.0;
    String colorBarPalette "KT_amp";
    String ioos_category "Location";
    String long_name "Magnitude of Sea Floor Depth Gradient";
    Float32 missing_value NaN;
    String units "m";
  }
  x_gradient {
    Float64 colorBarMaximum 0.05;
    Float64 colorBarMinimum -0.03;
    String colorBarPalette "KT_balance";
    String ioos_category "Location";
    String long_name "East-West Gradient of Sea Floor Depth";
    Float32 missing_value NaN;
    String units "m";
  }
  y_gradient {
    Float64 colorBarMaximum 0.05;
    Float64 colorBarMinimum -0.03;
    String colorBarPalette "KT_balance";
    String ioos_category "Location";
    String long_name "North-South Gradient of Sea Floor Depth";
    Float32 missing_value NaN;
    String units "m";
  }
  sea_floor_depth {
    Float64 colorBarMaximum 8000.0;
    Float64 colorBarMinimum -8000.0;
    String colorBarPalette "TopographyDepth";
    String ioos_category "Location";
    String long_name "Sea Floor Depth";
    Float32 missing_value NaN;
    String standard_name "sea_floor_depth";
    String units "m";
  }
  NC_GLOBAL {
    String _NCProperties "version=2,netcdf=4.6.2,hdf5=1.10.4";
    String cdm_data_type "Grid";
    String Conventions "COARDS, CF-1.6, ACDD-1.3";
    String creator_email "erd.data@noaa.gov";
    String creator_name "NOAA NMFS SWFSC ERD";
    String creator_type "institution";
    String creator_url "https://www.pfeg.noaa.gov";
    Float64 Easternmost_Easting 255.0;
    Float64 geospatial_lat_max 50.0;
    Float64 geospatial_lat_min 20.0;
    Float64 geospatial_lat_resolution 0.016666666666666666;
    String geospatial_lat_units "degrees_north";
    Float64 geospatial_lon_max 255.0;
    Float64 geospatial_lon_min 230.0;
    Float64 geospatial_lon_resolution 0.016666666666666666;
    String geospatial_lon_units "degrees_east";
    String history 
"created from etopousing python scikit-image canny algorithm, sigma = 10
2024-04-18T01:04:38Z (local files)
2024-04-18T01:04:38Z http://coastwatch.pfeg.noaa.gov/griddap/erdEtopoSeafloorGradient.das";
    String infoUrl "https://www.pfeg.noaa.gov";
    String institution "NOAA ERD";
    String keywords "bathymetry, data, depth, earth, Earth Science > Oceans > Bathymetry/Seafloor Topography > Bathymetry, east, east-west, erd, estimatedetoposea, floor, gradient, magnitude, magnitude_gradient, noaa, north, north-south, ocean, oceans, science, sea, sea_floor_depth, seafloor, south, topography, west, x_gradient, y_gradient";
    String keywords_vocabulary "GCMD Science Keywords";
    String license 
"The data may be used and redistributed for free but is not intended
for legal use, since it may contain inaccuracies. Neither the data
Contributor, ERD, NOAA, nor the United States Government, nor any
of their employees or contractors, makes any warranty, express or
implied, including warranties of merchantability and fitness for a
particular purpose, or assumes any legal liability for the accuracy,
completeness, or usefulness, of this information.
";
    Float64 Northernmost_Northing 50.0;
    String sourceUrl "(local files)";
    Float64 Southernmost_Northing 20.0;
    String standard_name_vocabulary "CF Standard Name Table v55";
    String summary "Estimated sea_floor depth  x-gradient, y-gradient and gradient magnitude using the Python scikit-image canny algorithm with sigma = 7.5, x-gradient, y-gradient and gradient magnitude. For the code used to create this dataset (and a description), see https://rmendels.github.io/seafloor_gradient_doc.html .";
    String title "Estimated Seafloor Depth Gradients: ETOPO (US West Coast)";
    Float64 Westernmost_Easting 230.0;
  }
}

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.