# [Rd] typo and user-proofing in odesolve() (PR#1295)

**bolker@zoo.ufl.edu
**
bolker@zoo.ufl.edu

*Fri, 1 Feb 2002 18:34:36 +0100 (MET)*

A couple of minor points about the odesolve package
(which I am otherwise enjoying very much):
1. "scalar" is misspelled as "scaler" in the definitions of
the rtol and atol parameters
2. it is possible to crash R by doing something dumb, e.g
failing to read the documentation carefully enough and (a)
returning only a vector of derivatives and not a list of
(derivatives, global values) and (b) making the derivative
vector shorter than the vector of initial conditions (see example below).
I know that this is my fault, but it might be possible/useful
to "user-proof" lsoda() some more (try func() once and see if
it returns a list of the appropriate form, check the derivative
vector for length matching the IC vector, etc ...
tderiv <- function(t,x,parms) {
# return(list(c(x[1]*parms[1],x[2]*parms[2],parms[3]*(x[1]+x[2])),NULL))
return(c(x[1]*parms[1],x[2]*parms[2],parms[3]*(x[1]+x[2])))
}
lsoda(rep(1,2),c(0:20),tderiv,c(0.01,-0.01,1.2))
--please do not edit the information below--
Version:
platform = i686-pc-linux-gnu
arch = i686
os = linux-gnu
system = i686, linux-gnu
status =
major = 1
minor = 3.1
year = 2001
month = 08
day = 31
language = R
Search Path:
.GlobalEnv, package:ctest, Autoloads, package:base
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