Displaying 10 results from an estimated 10 matches for "3e7".
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3,7
2004 Jun 10
0
lsoda with arbitrary zero thresholds (with psuedo-solution)
...ve a solution
> that kind of works but is rather inelegant and I think may be
> problematic in difficult systems.
> Borrowing from the lsoda example again I once again highlight the code
> that I have changed to put in place arbitrary thresholds:
> parms <- c(k1=0.04, k2=1e4, k3=3e7)
> my.atol <- c(1e-6, 1e-10, 1e-6)
> times <- seq(0,1000)
> lsexamp <- function(t, y, p)
> {
> if(y[1] < .4) yd1 <- -y[1] ### These if, else statements are new
> else yd1 <- -p["k1"] * y[1] + p["k2"] * y[2]*y[3]
> if(y[3...
2005 Nov 06
1
Problem defining a system of odes as a C library with lsoda
....c example bundled with
the package:
### START
rm(list=ls())
setwd("~/projects/test_odesolve")
invisible(file.remove("mymod.o","mymod.so"))
system("R CMD SHLIB mymod.c")
dyn.load("mymod.so")
require(odesolve)
parms <- c(k1 = 0.04, k2 = 1e4, k3=3e7)
my.atol <- c(1e-6, 1e-10, 1e-6)
times <- c(0, 4*10^(-1:10))
print(system.time(
out1 <- lsoda(c(1.0,0.0,0.0),times,"myderivs",
parms,
rtol=1e-4,atol=my.atol,jacfunc="myjac",...
2009 Mar 27
0
imporving performance of slicing on matrices and S4 their derivatives
...memcpy(REAL(res), REAL(m), nrow*ncol*sizeof(double));
UNPROTECT(2);
return res;"
mcols = cfunction(signature(m="matrix"), body=body,
includes="#include <string.h>")
## --- tests ---------------------------------------------------
m = matrix(runif(3e7), nc=3)
setClass("MyClass", representation("matrix", comment="character"))
dat = new("MyClass", m, comment="test object")
mean(sapply(1:20, function(i) system.time(dat at .Data)[1] ))
## output: [1] 0.2526
mean(sapply(1:20, function(i) system.time...
2017 Jun 18
3
R_using non linear regression with constraints
...0
, b = 0.05
)
, lower = c( 1000, 0 )
, upper = c( 3000, 1 )
)
a <- as.vector( coef( myfit )[ "a" ] )
b <- as.vector( coef( myfit )[ "b" ] )
brks <- c( 500, 1e7, 2e7, 3e7, 4e7 )
ggplot( objdtass, aes( x=a, y=b, z = x, fill=x ) ) +
geom_tile() +
geom_contour( breaks= brks ) +
geom_point( x=a, y=b, colour="red" ) +
geom_point( x=objdtassmin$a
, y=objdtassmin$b
, colour="green" ) +
scale_fill_co...
2003 Apr 24
0
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2017 Jun 18
0
R_using non linear regression with constraints
...5
> )
> , lower = c( 1000, 0 )
> , upper = c( 3000, 1 )
> )
> a <- as.vector( coef( myfit )[ "a" ] )
> b <- as.vector( coef( myfit )[ "b" ] )
>
> brks <- c( 500, 1e7, 2e7, 3e7, 4e7 )
> ggplot( objdtass, aes( x=a, y=b, z = x, fill=x ) ) +
> geom_tile() +
> geom_contour( breaks= brks ) +
> geom_point( x=a, y=b, colour="red" ) +
> geom_point( x=objdtassmin$a
> , y=objdtassmin$b
> , colour="...
2016 Oct 26
5
BUG?: On Linux setTimeLimit() fails to propagate timeout error when it occurs (works on Windows)
setTimeLimit(elapsed=1) causes a timeout error whenever a call takes
more than one second. For instance, this is how it works on Windows
(R 3.3.1):
> setTimeLimit(elapsed=1)
> Sys.sleep(10); message("done")
Error in Sys.sleep(10) : reached elapsed time limit
Also, the error propagates immediately and causes an interrupt after ~1 second;
> system.time({ Sys.sleep(10);
2017 Jun 18
0
R_using non linear regression with constraints
I ran the following script. I satisfied the constraint by
making a*b a single parameter, which isn't always possible.
I also ran nlxb() from nlsr package, and this gives singular
values of the Jacobian. In the unconstrained case, the svs are
pretty awful, and I wouldn't trust the results as a model, though
the minimum is probably OK. The constrained result has a much
larger sum of squares.
2017 Jun 18
3
R_using non linear regression with constraints
https://cran.r-project.org/web/views/Optimization.html
(Cran's optimization task view -- as always, you should search before posting)
In general, nonlinear optimization with nonlinear constraints is hard,
and the strategy used here (multiplying by a*b < 1000) may not work --
it introduces a discontinuity into the objective function, so
gradient based methods may in particular be
2008 Jun 30
4
Rebuild of kernel 2.6.9-67.0.20.EL failure
Hello list.
I'm trying to rebuild the 2.6.9.67.0.20.EL kernel, but it fails even without
modifications.
How did I try it?
Created a (non-root) build environment (not a mock )
Installed the kernel.scr.rpm and did a
rpmbuild -ba --target=`uname -m` kernel-2.6.spec 2> prep-err.log | tee
prep-out.log
The build failed at the end:
Processing files: kernel-xenU-devel-2.6.9-67.0.20.EL
Checking