Combinations

Combinations are ConTeXt's way to align several pictures (preferrably at same size):

\startcombination[x*y]
{something}{caption} ...
...
\stopcombination

means:

You define, how much figures in columns * rows you'd like to align.

You must provide one "figure something" (e.g. an \externalfigure) and a caption for every "cell".

The sample, from the manual, shows how to define a caption for the whole group and use it as float (see Floating Objects):

\placefigure
[here] % placement option
[fig:combinations] % reference
{An example of combination} % caption for whole group
{
\startcombination[3*2] % 3 columns, 2 rows
{\externalfigure[lb00220]} {a} {\externalfigure[lb00221]} {b} % picture and caption for two figures in first row
{\externalfigure[lb00222]} {c} {\externalfigure[lb00223]} {d}
{\externalfigure[lb00225]} {e} {\externalfigure[lb00226]} {f}
\stopcombination
} % whole combination in braces of placefigure

Setup

There is \setupcombinations command.

Referencing

To reference a subfigure you can provide the subfigure's caption as a second parameter to the \in command.

To reference the subfigure with the caption d you would write:

\in{figure}{d}[fig:combinations]

This would produce something like 'figure 2.4d'. The content of the second parameter simply gets appended to the end of the figure's reference-number, thus the example above would still work even if the caption would be 'd) An awesome subfigure'.