[R] Specify custom par(mfrow()) layout for defined plot()

[Michael Bach]

Dear R Users,

I am doing stats::decompose() on 4 different time series.  When I issue

csdA <- decompose(tsA)
plot(csdA)

I get a summary plot for observed, trend, seasonal and random components
of decomposed time series tsA.  As I understand it, the object returned
by decompose() has it's own plot method where mfrow(4,1) etc. is
defined.  Now suppose I wanted to wrap those mfrow(4,1) into my own
mfrow(2,2) layout.  How could I achieve this?  Is there a general way to
handle these cases?  Something like a "meta" par(mfrow())?

Best Regards,
Michael Bach