Message-ID: <alpine.DEB.2.20.1708241110230.2616@luke-Latitude>
Date: 2017-08-24T16:10:58Z
From: Luke Tierney
Subject: loop compilation problem
In-Reply-To: <8EA1A94F-EB30-4AE0-A399-C9F73BC33EB5@oracle.com>
Thanks.
Here is a simplified version:
library(compiler)
zero <- 0
one <- 1
expr <- quote((z <- zero + one) + (z <- z + 1))
eval(compiler::compile(expr))
Sill fix shortly.
Best,
luke
On Thu, 24 Aug 2017, Lukas Stadler wrote:
> Hi!
>
> We?ve seen a problem with the compiler in specific cases of matrix updates:
>
>> { m <- matrix(1:4, 2) ; z <- 0; for(i in 1) { m[z <- z + 1,z <- z + 1] <- 99; } ; m }
> [,1] [,2]
> [1,] 1 3
> [2,] 2 99
>
> Here, it modifies element [2,2], which is unexpected.
> It behaves correct without the loop:
>
>> { m <- matrix(1:4, 2) ; z <- 0; m[z <- z + 1,z <- z + 1] <- 99 ; m }
> [,1] [,2]
> [1,] 1 99
> [2,] 2 4
>
> ? and without the jit:
>
>> enableJIT(0)
> [1] 3
>> { m <- matrix(1:4, 2) ; z <- 0; for(i in 1) { m[z <- z + 1,z <- z + 1] <- 99; } ; m }
> [,1] [,2]
> [1,] 1 99
> [2,] 2 4
>
> I checked with "R Under development (unstable) (2017-08-23 r73116)?, and the problem is still there.
>
> - Lukas
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
--
Luke Tierney
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa Phone: 319-335-3386
Department of Statistics and Fax: 319-335-3017
Actuarial Science
241 Schaeffer Hall email: luke-tierney at uiowa.edu
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu