multiAssetOptions (version 0.1-2)

nodeSpacer: Non-Uniform Finite Difference Node Spacer

Description

nodeSpacer implements the spatial discretization scheme from Hout and Foulon (2010) with arbitrary left and right bounds. The function additionally includes logic for mesh shifting.

Usage

nodeSpacer(K, leftBound, rightBound, nodes, density, kShift)

Arguments

K

scalar; option strike.

leftBound

scalar; near spatial boundary of the underlying domain.

rightBound

scalar; far spatial boundary of the underlying domain.

nodes

integer; number of nodes used in the spatial discretization.

density

scalar; impacts the concentration of nodes around the option strike. At 0, nodes are uniformly distributed between the leftBound and rightBound. Increasing the parameter increases the node concentration around the strike.

kShift

case; if 0, no mesh shifting, if 1, adjusts the node spacing such that the strike falls exactly between two nodes, if 2, adjusts the node spacing such that the strike falls exactly on a node. See Tavella and Randall (2000).

Value

nodeSpacer returns a vector of gridpoints used in spatial discretization in the finite difference method. The nodes input determines the length of the output vector.

Details

Mesh shifting is accomplished by multiplying the vector of gridpoints by a scalar. For multi-asset options, this nodeSpacer is called iteratively to discretize each underlying's spatial domain.

References

Hout, K. J., Foulon, S., 2010. ADI finite difference schemes for option pricing in the Heston model with correlation. International Journal of Numerical Analysis and Modeling, 7 (2), 303--320. http://www.math.ualberta.ca/ijnam/Volume-7-2010/No-2-10/2010-02-06.pdf

Pooley, D. M., Vetzal, K. R., Forsyth, P. A., 2002. Convergence remedies for non-smooth payoffs in option pricing. https://cs.uwaterloo.ca/~paforsyt/report.pdf

Tavella, D., Randall, C., 2000. Pricing Financial Instruments: The Finite Difference Method. John Wiley & Sons, Inc., New York.

Examples

# NOT RUN {
# sample mesh spacing
plot(nodeSpacer(100, 0, 500, 26, 5, 1), rep(0, times=26), main='Non-Uniform Mesh Spacing',
  xlab='Underlying Price (Strike = 100)', ylab='', yaxt='n', type='p', cex=0.5, pch=16)
# }