Grid variable at ``current'' point depends on value at
two previous time steps (a second order scheme in time). We
thus need to specify initial data for all
at times
and
.
Grid variable at ``current'' point depends on values at adjacent locations on the string (at previous time).
Difference scheme is explicit (thus
parallelizable); that is, each grid variable at time
depends only on grid variables at previous time instants. This is a
very desirable property.