我在处理与R一起使用的Fortran中的实数时遇到麻烦.以下代码用Fortran编写:
I am having trouble handling reals in Fortran, which I use together with R. The following code is written in Fortran:
Subroutine realtest(lol) implicit none Real lol lol = 10.0 End我用命令R CMD SHLIB realtest.f进行编译.如果我在R中以以下方式运行共享库:
I compile with the command R CMD SHLIB realtest.f. If I run the shared object in R as:
dyn.load("realtest.so") res <- .Fortran("realtest",lol= as.numeric(1.2))lol的结果值为1.2，但应该为10.如果我用Integers进行整件事，我会得到正确的值10.
The resulting value of lol is 1.2, but it should have been 10. If I do the whole thing with Integers instead, I get the correct value 10.
推荐答案尝试使用double precision代替real；以下对我有用:
Try using double precision instead of real; the following works for me:
! realtest.f90 ! subroutine realtest(x) implicit none double precision, intent(inout) :: x x = 10.0 end subroutine realtest从R
dyn.load("realtest.so") res <- .Fortran("realtest", x = as.double(1.2)) res # $x # [1] 10