Displaying 20 results from an estimated 4000 matches similar to: "Need help to understand integrate function"
2006 May 24
1
problem-nlme
Hi,
I have great problems with my work in R.
I look for to model the growth of fish.
I have "Longitudinal data", a serie of repeated
measures for each individual.
Using the corresponding packages "nlme" in R.
I treat to fit to the data different growth functions,
wich were entered by me.
Unfortunately for no it was arrived at the
convergence, several error messages appeared.
I
2009 Oct 17
1
custom selfStart model works with getInitial but not nls
Hello,
I'm having problems creating and using a selfStart model with nlme. Briefly,
I've defined the model, a selfStart object, and then combined them to make a
selfStart.default model.
If I apply getInitial to the selfStart model, I get results. However, if I try
usint it with nls or nlsList, these routines complain about a lack of initial
conditions.
If someone could point out
2015 Nov 21
2
[lld] R_MIPS_HI16 / R_MIPS_LO16 calculation
On Sat, Nov 21, 2015 at 9:28 AM, Rui Ueyama <ruiu at google.com> wrote:
> On Fri, Nov 20, 2015 at 10:13 PM, Simon Atanasyan <simon at atanasyan.com>
> wrote:
>>
>> In case of MIPS O32 ABI we have to find a matching R_MIPS_LO16
>> relocation to calculate R_MIPS_HI16 one because R_MIPS_HI16 uses
>> combined addend (AHI << 16) + (short)ALO where AHI is
2016 Aug 02
2
Instruction selection problems due to SelectionDAGBuilder
Hello.
I'm having problems at instruction selection with my back end with the following
basic-block due to a vector add with immediate constant vector (obtained by vectorizing a
simple C program doing vector sum map):
vector.ph: ; preds = %vector.memcheck50
%.splatinsert = insertelement <8 x i64> undef, i64 %i.07.unr, i32 0
2017 Jul 20
3
Issue with DAG legalization of brcond, setcc, xor
Hi,
I am having some issues with how some of the instructions are being
legalized.
So this is my intial basic block. The area of concern is the last three
instructions. I will pick and choose debug output to keep this small.
SelectionDAG has 36 nodes:
t0: ch = EntryToken
t6: i32,ch = CopyFromReg t0, Register:i32 %vreg507
t2: i32,ch = CopyFromReg t0, Register:i32 %vreg17
2010 Sep 17
7
removing specific rows from array
I'm attempting to create an array of treatment comparisons for modelling data generation. This involves comparison of one treatment (c2) with another (c3), relative to a common comparator (c1).
Attached code gives me the correct array but need to remove duplicates. Duplicates relate only to c2 and c3
such that I need to remove
r3 because c2 and c3 are same as r1 with c2 and c3 swapped
r5
2017 Feb 14
2
Ensuring chain dependencies with expansion to libcalls
Hi all,
Our target does not have native support for 64-bit integers, so we rely on
library calls for certain operations (like sdiv). We recently ran into a
problem where these operations that are expanded to library calls aren't
maintaining the proper ordering in relation to other chains in the DAG.
The following snippet of a DAG demonstrates the problem.
t0: ch = EntryToken
t2:
2016 Nov 03
2
rotl: undocumented LLVM instruction?
Is there any way to get it to delay this optimization where it goes from
this:
Initial selection DAG: BB#0 'bclr64:entry'
SelectionDAG has 14 nodes:
t0: ch = EntryToken
t2: i64,ch = CopyFromReg t0, Register:i64 %vreg0
t4: i64,ch = CopyFromReg t0, Register:i64 %vreg1
t6: i64 = sub t4, Constant:i64<1>
t7: i64 = shl Constant:i64<1>, t6
2017 Jul 21
4
Issue with DAG legalization of brcond, setcc, xor
But isn't kinda silly that we transform to xor and then we transform it
back. What is the advantage in doing so? Also, since we do that method, I
now have to introduce setcc patterns for i1 values, instead of being able
to just use logical pattern operators like not.
-Dilan
On Fri, Jul 21, 2017 at 11:00 AM Dilan Manatunga <manatunga at gmail.com>
wrote:
> For some reason I
2011 Oct 20
1
Applying function with separate dataframe (calibration file) supplying some inputs
Hello,
I am not entirely sure the subject line captures what I am trying to do, but
hopefully this description of the problem will help folks to see my
challenge and hopefully offer constructive assistance.
I have an experimental setup where I measure the decrease in oxygen in small
vials as an organism, such as an oyster, consumes the oxygen. Each vial is
calibrated before the experiment and
2001 Dec 14
1
nls fit to exponential decay with unknown time origin
I'm trying to use nls() to fit an exponential decay with an unknown offset
in the time (independent variable). (Perhaps this is inherently very
difficult?).
> decay.pl <- nls (amp ~ expn(b0,b1,tau,t0,t), data = decay,
+ start = c(b0=1, b1=7.5, tau=3.5, t0=0.1), trace=T)
Error in nlsModel(formula, mf, start) : singular gradient matrix at
initial parameter estimates
2002 Mar 26
1
seq.POSIXt() with short time intervals
I was surprised when seq.POSIXt() returned a single value rather than
a vector, from inputs that I thought were reasonable. Here's an
example to illustrate:
> t0 <- ISOdatetime(2002,6,24,0,0,10)
## expected a sequence of 16 times 1 second apart
> seq.POSIXt(from=t0,to=t0+15,by='1 sec')
[1] "2002-06-24 00:00:10 PDT"
## traces to this call
>
2015 Nov 21
2
[lld] R_MIPS_HI16 / R_MIPS_LO16 calculation
On Sat, Nov 21, 2015 at 10:08 AM, Rui Ueyama <ruiu at google.com> wrote:
> On Fri, Nov 20, 2015 at 11:02 PM, Simon Atanasyan <simon at atanasyan.com>
> wrote:
>>
>> On Sat, Nov 21, 2015 at 9:28 AM, Rui Ueyama <ruiu at google.com> wrote:
>> > On Fri, Nov 20, 2015 at 10:13 PM, Simon Atanasyan <simon at atanasyan.com>
>> > wrote:
>>
2016 Nov 03
3
rotl: undocumented LLVM instruction?
Setting the ISD::ROTL to Expand doesn't work? (via SetOperation)
You could also do a Custom hook if that's what you're looking for.
On Thu, Nov 3, 2016 at 5:12 PM, Phil Tomson <phil.a.tomson at gmail.com> wrote:
> ... or perhaps to rephrase:
>
> In 3.9 it seems to be doing a smaller combine much sooner, whereas in 3.6
> it deferred that till later in the
2001 Sep 07
3
fitting models with gnls
Dear R-list members,
Some months ago I wrote a message on the usage of gnls (nlme library) and here I come again.
Let me give an example:
I have a 10 year length-at-age data set of 10 fishes (see growth.dat at the end of this message) and I want to fit a von Bertalanffy growth model, Li= Linf*(1-exp(-k*(ti-t0))) where Li = length at age i, Linf= asymptotic length, k= curvature parameter, ti=
2007 Sep 21
1
problem with 'integrate'
Hello -
I am having a problem with the function 'integrate'. I am running R
on OSX (R 2.5.1).
I am trying to suppress the error message when 'integrate' attempts
to integrate across a parameter set giving a non-finite function
value. I'm using it in a MCMC / simulated annealing algorithm, and
it is entirely possible that some parameter sets will give non-
2006 Feb 28
1
Collinearity in nls problem
Dear R-Help list,
I have a nonlinear least squares problem, which involves a changepoint;
at the beginning, the outcome y is constant, and after a delay, t0, y
follows a biexponential decay. I log-transform the data, to stabilize
the error variance. At time t < t0, my model is
log(y_i)=log(exp(a0)+exp(b0))
at time t >= t0, the model is
log(y_i)=log(exp(a0-a1*(t_i - t0))+exp(b0=b1*(t_i -
2012 Jul 29
1
Return od functions
Hi!
I have some questions about R function. I try to write a function for
multi-returns. The function code is as attachment.
dgp.par<-function(ai, bi, t, n)
{
t0<-t+20
y0<-matrix(0, nr=t0, nc=n)
y0[1,]<-ai/(1-bi)
for(tt in 2:t0)
{ y0[tt,]<-ai+bi*y0[tt-1,]+rnorm(n, 0, 1) }
y<-y0[21:t0,]
x<-y0[20:t0-1,]
z<-y0[19:t0-2,]
z<-z[2:t,]
dy<-y[2:t,]-y[1:t-1,]
2016 Nov 03
2
rotl: undocumented LLVM instruction?
One option may be to prevent the formation of ROTL, if possible, and
then generating rol by hand.
Marking it as "expand" would likely stop the DAG combiner from creating
it. Then you could "preprocess" the selection DAG before the instruction
selection and do the pattern matching yourself.
-Krzysztof
On 11/3/2016 4:24 PM, Phil Tomson via llvm-dev wrote:
> I could try
2009 Mar 15
1
Conversion and rounding of POSIXct
POSIXct/lt supports fractional seconds (see Sub-second Accuracy
section of man page), but there seem to be some inconsistencies in
their handling.
Converting to POSIXlt and back does not give back the same time for
times before the origin:
> t0 <- as.POSIXct('1934-01-05 23:59:59.00001')
> t0
[1] "1934-01-06 00:00:00 EST" # rounding issue, see below
>