CONCATENATE Concatenates multiple plots from left to right.
CONCATENATE(x,y,y_lim) plots each element (vector) of the cell array X
with the corresponding element(vector) of the cell array Y when Y is a
1-D cell array(i.e. the length of the cell array X has to be exactly
the same as the length of the cell array Y)

When yeach ele is not a 1-D cell array, but rather a 2-D cell array, CONCATENATE(x,y,y_lim)
plots each element of the 1-D cell array X with the corresponding element
of the cell array Y through the second dimension and plots the elements
of Y in the first dimension over (i.e. the length of the cell array X
has to be exactly the same as SIZE(Y,2))

CONCATENATE(x,y,y_lim,len) plots each element (vector) of the cell array X
with the corresponding element(vector) of the cell array Y, with each
plot having the corresponding size weight in LEN
LEN: is a 1-D vector containing the size of each of the concatenated
plot, the summation of the elements in LEN has to be exactly 1.
example: LEN=[0.25, 0.5, 0.25] for three concatenated plots