You can use the function
treeviewer to display a graphical representation
of a tree, allowing you to examine interactively the prices and rates
on the nodes of the tree until maturity. To get started with this
process, first load the data file
in this toolbox.
treeviewer price tree diagrams follow the
convention that increasing prices appear on the upper branch of a
tree and, consequently, decreasing prices appear on the lower branch.
Conversely, for interest rate displays, decreasing interest
rates appear on the upper branch (prices are rising) and increasing interest
rates on the lower branch (prices are falling).
For information on the use of
observe interest rate movement, see Observing Interest Rates. For information
treeviewer to observe
the movement of prices, see Observing Instrument Prices.
If you provide the name of an interest rate tree to the
treeviewer function, it displays a graphical
view of the path of interest rates. For example, here is the
treeviewer representation of all the
rates along both the up and down branches of
FRates = bushpath(HJMTree.FwdTree, [1 2 2])
FRates = 1.0356 1.0364 1.0526 1.0674
you can display the identical information by clicking along the same
sequence of nodes, as shown next.
Next is a
of interest rates along several branches of
recombining trees, such as BDT, BK, and HW, you must click each node
in succession from the beginning to the end. Because these trees can
treeviewer is unable
to complete the path automatically.
FRates = treepath(BDTTree.FwdTree, [1 2 2])
FRates = 1.1000 1.0979 1.1377 1.1606
You can display the identical information by clicking along the same sequence of nodes, as shown next.
load deriv.mat [Price, PriceTree] = hjmprice(HJMTree, HJMInstSet); treeviewer(PriceTree, HJMInstSet)
select each instrument individually in the instrument
portfolio for display.
You can use an analogous process to view instrument prices based
on the BDT interest rate tree included in
load deriv.mat [BDTPrice, BDTPriceTree] = bdtprice(BDTTree, BDTInstSet); treeviewer(BDTPriceTree, BDTInstSet)
You can use
to observe instrument prices through time. For the first 4% bond in
the HJM instrument portfolio,
a valuation date price of 98.72, the same value obtained by accessing
PriceTree structure directly.
As a further example, look at the sixth instrument in the price
vector, the 3% cap. At the valuation date, its value obtained directly
from the structure is 6.2831. Use
this instrument to confirm this price.
The second node represents the first-rate observation time,
= 1. This node displays two states, one representing the
branch going up and the other one representing the branch going down.
Examine the prices of the node corresponding to the up branch.
ans = 100.1563 99.7309 0.1007 100.1563 100.3782 3.2594 0.1007 3.5597
Now examine the corresponding down branch.
ans = 96.3041 94.1986 0 96.3041 100.3671 8.6342 0 -0.3923
treeviewer once again,
now to observe the price of the 4% bond on the down branch. The displayed
price of 96.3 conforms to the price obtained from direct access of
PriceTree structure. You may continue this
process as far along the price tree as you want.