felopt <file> <ix_uni>    -- Read in felopt data file.
                             ix_uni is an optional universe number to apply
                             the data to. ix_uni = "ALL" applies the data
                             to all the universes. The default universe
                             is the currently viewd universe.

matrix <ix1> <ix2>        -- Compute the linear transport matrix from the
                             exit end of ix1 to the exit end of ix2 and
                             print this result. 
                             ix1 and ix2 are element indexes.

snap <directory> <ix_uni> -- Read in snap files.
                             ix_uni is an optional universe number to apply
                             the data to. ix_uni = "ALL" applies the data
                             to all the universes. The default universe
                             is the currently viewd universe.

set bbu <var> = <value>   -- Set BBU variable. 
                             Use "show" to get a list of names.

set matrix <file>         -- Set the matrix for an element or elements.

show bbu                  -- Show BBU varaible values.

bbu track                 -- BBU tracking.
bbu threshold             -- BBU threshold current calc.

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graph%type = "bbu_power"
curve%