[R] building an expression

[Prof Brian Ripley]

On 7 May 2003, michaell taylor wrote:

[...]

> I am close, but not quite there.  I am left with the eq object:
> > eq
> [1] "0.0188900087591286"         "d1$b * -0.0192141899003632"
> [3] "d1$c * 0.158235007749465"  
> 
> which needs converting into a single eval() 'able.  seems like some sort
> of do.call(expression, eq) sort of construction is the way to go, but
> clearly I am not getting the syntax correct.

parse(text=paste(eq, collapse="+"))

would give you the expression 

0.0188900087591286 + d1$b * -0.0192141899003632 + d1$c * 0.158235007749465

which appears to be what you want (although you did not say addition was
involved: you also seem to be assuming a linear model in [...]).

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
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