A numerical vector of the form 'c(bottom, left, top, right)'
which gives the number of lines of margin to be specified on
the four sides of the plot, for details see par.
oma
A vector of the form 'c(bottom, left, top, right)' giving
the size of the outer margins in lines of text.
ylab
a label for the y axis, for details see plot.default.
Absolute yield and price errors as a resuslt of the term structure estimation can be plotted.
The scaling of the x axis depends on the maturity of the bonds, each bond is labeled with its
ISIN number. The error plots seems especially useful in identifying misspriced bonds. For removing them,
the function rm_bond may be applied.