DODS Quick Start Guide -- 1.1 Peeking at Data

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1.1 Peeking at Data

Now that we know a little about the shape of the data, and the data attributes, let's look at some of the data.

You can request a piece of an array with subscripts, just like in a C program or in Matlab or many other computer languages. Use a colon to indicate a subscript range.

...sst/mnmean.nc.asc?time[0:6]

This URL will produce the following:

Part of a vector.

You can do the same for one of the grids:

...sst/mnmean.nc.asc?mask[28:30][206:209]

Which produces a portion of the land mask somewhere near Alaska's Kenai peninsula:

Part of a DODS Grid.

Notice that when you ask for part of a DODS Grid, you get the array part along with the corresponding parts of the map vectors.

If you are interested in the Reynolds dataset, you are probably more interested in the sea surface temperature data than the land mask. The temperature data is a three-dimensional grid. To sample the sst Grid, you just add a dimension for time:

...sst/mnmean.nc.asc?sst[12:13][28:30][206:209]

This produces something likethis:

Part of the Reynolds SST data

Note that the sst values are in celsius degrees multiplied by 100, as indicated by the scale_factor attribute of the DAS. Further, it's important to remember with this dataset, that the data were obtained by calculating spatial and temporal means. Consequently, the data points in the sst array should be ignored when the corresponding entry in the mask array indicates they are over land.

Tom Sgouros, 2004/07/07