### data cube

("table" of numerical data covering three dimensions)

The phrase **data cube** refers to a three-dimensional array of data
points, i.e., values of some sort. It is analogous to a table,
which is a two-dimensional array of data points. Printing a
data cube on paper might be accomplished with a series of tables:
in this case, tracing the data through either of two dimensions
could be tracing across a column or row in the table, but tracing
data through the third dimension requires looking at successive tables.

A table, for example, might be constructed with the height above
sea level of grid points evenly spread on a rectangular plot of
land. An example of a data cube might be temperature values
at points in space evenly distributed throughout a room, e.g., at
one centimeter intervals in each of the three dimensions.

The three dimensions may not be analogous. For
example, in astronomy, two spatial dimensions across the
celestial sphere are straight-forward to collect and represent,
and often some other third dimension is used if the collected data
consists of a series of values from that point. Wavelength
or frequency is a useful third dimension for data from
integral field spectrographs. Another useful dimension is
redshift, for distant very objects such as distant galaxies.
A third is a straight-forward interpretation of redshift:
radial velocity, e.g., for targets within the Milky Way
such as groups of clouds. In all these cases, the data cube
is a natural way to store the raw or nearly-raw data.

(*computing,astronomy,data*)
**Further reading:**

http://en.wikipedia.org/wiki/Data_cube

**Referenced by pages:**

linearly variable filter (LVF)

pipeline

position-position-velocity space (PPV)

redshift space

Index