What makes things Listable?
- To: mathgroup at smc.vnet.net
- Subject: [mg26302] What makes things Listable?
- From: Chris Johnson <cjohnson at shell.faradic.net>
- Date: Sun, 10 Dec 2000 00:20:11 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
I'm using the "Finance Essentials" package and want to use the Value
command over a list of bonds. For those not familiar with the package,
there is a structure called Bonds which defines the coupon, maturity,
etc. for a bond. The Value command takes three arguements, Bond,
SettlementDate, YieldToMaturity and returns a price.
Having vectors of Bonds, Dates, and Yields, I want to create a vector
of prices. My first guess was to try the following command:
Value[Transpose[{bondlist,datelist,yields}]]
This returned the result
Value[{{bond[1],valdate[1],yield[1]},...}]
My next step was to use Map[Value,Transpose[...]] which returned a list
like {Value[{bond,valdate,ytm}],...} where the parameters for Value are
surrounded by curly braces. Value wouldn't evaluate over parameters in
this form.
The solution I found for now is to create my own fuction
cjValueList[{x_,y_,z_}]:=Value[x,y,z]
and then mapping cjValueList provides the table I seek. I have run into
this general problem of wanting to get rid of the outer level of curly
braces before, and wonder if there is a more general solution then this
hack redefinition of the function?
Thanks,
Chris Johnson
- Follow-Ups:
- Re: What makes things Listable?
- From: "Carl K. Woll" <carlw@u.washington.edu>
- Re: What makes things Listable?