Displaying 20 results from an estimated 5000 matches similar to: "Weighted Sum Optimization in R (Maximization)"
2012 Nov 28
1
Help setting optimization problem to include more constraints
Dear R-helpers,
I am struggling with an optimization problem at the moment and decided to
write the list looking for some help. I will use a very small example to
explain what I would like to. Thanks in advance for your help.
We would like to distribute resources from 4 warehouses to 3 destinations.
The costs associated are as follows:
Destination
>From 1 2 3 Total
2011 Jan 10
2
Calculating Portfolio Standard deviation
Dear R helpers
I have following data
stocks <- c("ABC", "DEF", "GHI", "JKL")
prices_df <- data.frame(ABC = c(17,24,15,22,16,22,17,22,15,19),
DEF = c(22,28,20,20,28,26,29,18,24,21),
GHI = c(32,27,32,36,37,37,34,23,25,32),
2013 Mar 12
2
big edge list to adjacency matrix
I have huge list of edges with weights.
a1 b1 w1
a2 b2 w2
a3 b3 w3
a1 b1 w4
a3 b1 w5
I have to convert it into 2 dim matrix
b1 b2 b3
a1 max(w1,w4) 0 0
a2 0 w2 0
a3 w5 0 w3
if edges repeated take the maximum weights. How do this efficiently without
using for loop? Any idea.
thanks
Avi
[[alternative
2014 Sep 02
3
[LLVMdev] LICM promoting memory to scalar
All,
If we can speculatively execute a load instruction, why isn’t it safe to hoist it out by promoting it to a scalar in LICM pass?
There is a comment in LICM pass that if a load/store is conditional then it is not safe because it would break the LLVM concurrency model (See commit 73bfa4a).
It has an IR test for checking this in test/Transforms/LICM/scalar-promote-memmodel.ll
However, I have
2014 Sep 02
2
[LLVMdev] LICM promoting memory to scalar
I think gcc is right.
It inserted a branch for n == 0 (the cbz at the top), so that's not a problem.
In all other regards, this is safe: if you examine the sequence of loads and stores, it eliminated all but the first load and all but the last store. How's that unsafe?
If I had to guess, the bug here is that LLVM doesn't want to hoist the load over the condition (which it is right
2014 Sep 03
3
[LLVMdev] LICM promoting memory to scalar
Thanks for the background on the concurrent memory model.
So, is it sufficient that the loop entry is guarded by condition (cbz at
top) for preventing the race?
The loop entry will be guarded by condition if loop has been rotated by loop
rotate pass.
Since LICM runs after loop rotate, we can use
ScalarEvolution::isLoopEntryGuardedByCond to check if we can speculatively
execute load without
2011 Jan 11
1
how to sort new data frame based on the original data frame
I have a really simple question
I have a data frame of 8 variables (the first column is the subjects' id):
SubID G1 G2 G3 G4 W1 W2 W3 W4
1 6 5 6 2 6 2 2 4
2 6 4 7 2 6 6 2 3
3 5 5 5 5 5 5 4 5
2006 Nov 15
2
??: Re:??: Re: Need help in waveslim package: imodwt and universal.thresh.modwt
Airon,
I don't think you have to find an English computer 'cause the
following must work in your Chinese one :-)
Let me explain. First of all, change your lines to
xdata <- ckhdat$Adj..Close[1:1447]
#names(ckhdwt.la8) <- c("w1", "w2", "w3", "w4", "w5","w6", "v6")
note the # sign, i.e., DO NOT change the names
2009 Apr 04
2
data.frame, converting row data to columns
I have a data frame something like:
name wrist
nLevel emot
1 4094 3.34 1
frustrated
2 4094 3.94 1
frustrated
3 4094 NA 1
frustrated
4 4094 3.51
2010 Oct 13
4
loop
Dear all,
I am trying to run a loop in my codes, but the software returns an error: "subscript out of bounds"
I dont understand exactly why this is happenning. My codes are the following:
rm(list=ls()) #remove almost everything in the memory
set.seed(180185)
nsim <- 10
mresultx <- matrix(-99, nrow=1000, ncol=nsim)
mresultb <- matrix(-99, nrow=1000, ncol=nsim)
N
2011 Sep 07
1
Imposing Feller condition using project constraint in spg
Dear R-users,
I'm running a maximization problem in which I want to impose a condition on
the relationship between 2 parameters.
The condition is that w[4] = (1+eps)/(2*w[1]), or equivalently w[4]*w[1] =
(1+eps)/2 , where eps is some small positive constant.
I've been trying to formulate a function that takes care of this, but I
can't really make it work so any suggestions would be
2009 Mar 24
1
Discriminant analysis - stepwise procedure
Dear R users,
I have some environmental variables and I need to find the best combination
of them in order to separate two main groups (coded 1 and 2). I have
performed a discriminant analysis using the stepclass function as a method
for selecting the most relevant environmental variables.
The problem is that this function includes a parameter (start.vars) and my
results change a lot when I
2007 Apr 24
1
Values greater than 1 or lower than -1 in ARMAacf
Dear all,
I need to compute the ACF (autocorrel) of an AR6 process, given the values
of its parameters (w1,w2,w3,w4,w5,w6).
First, I notice that there is an error as soon as the sum of the wi equals 1
:
"Error in drop(.Call("La_dgesv", a, as.matrix(b), tol, PACKAGE = "base")) :
system is computationally singular: reciprocal condition number =
1.00757e-18"
2007 Mar 24
2
sampling from the unoform distrubuton over a convex hull
Dear list,
Does anyone have a suggestion (or better still) code for sampling from the uniform distribution over the convex hull of a set of points?
Many thanks and best wishes,
Ranjan
2008 Oct 10
1
Correlation among correlation matrices cor() - Interpretation
Hello,
If I have two correlation matrices (e.g. one for each of two treatments) and
then perform cor() on those two correlation matrices is this third
correlation matrix interpreted as the correlation between the two
treatments?
In my sample below I would interpret that the treatments are 0.28
correlated. Is this correct?
> var1<- c(.000000000008, .09, .1234, .5670008, .00110011002200,
2006 Apr 28
1
unrooted tree and margins, ape package
Hello,
I have a question about margins when plotting an unrooted tree
(type="unrooted") with the 'ape' package ver. 1.7. When I plot an unrooted
tree with:
no.margin=TRUE
it seems that the margins are still there. It appears to be only when
type="unrooted".
I'm plotting multiple plots using layout() and would like to be able to get
rid of the margins or if
2020 May 05
2
"Earlyclobber" but for a subset of the inputs
Hi Quentin,
> It sounds like you only need the earlyclobber description for the N, N
> variant.
> In other words, as long as you use different opcodes for widen-op NN and
> widen-op WN, you model exactly what you want.
>
> What am I missing?
>
we are using different opcodes for widen-op NN and widen-op WN.
My understanding is that not setting earlyclobber to the W, N
2008 Apr 05
2
How to improve the "OPTIM" results
Dear R users,
I used to "OPTIM" to minimize the obj. function below. Even though I used
the true parameter values as initial values, the results are not very good.
How could I improve my results? Any suggestion will be greatly appreciated.
Regards,
Kathryn Lord
#------------------------------------------------------------------------------------------
x = c(0.35938587,
2008 Apr 05
2
How to improve the "OPTIM" results
Dear R users,
I used to "OPTIM" to minimize the obj. function below. Even though I used
the true parameter values as initial values, the results are not very good.
How could I improve my results? Any suggestion will be greatly appreciated.
Regards,
Kathryn Lord
#------------------------------------------------------------------------------------------
x = c(0.35938587,
2008 Mar 22
1
Simulating Conditional Distributions
Dear R-Help List,
I'm trying to simulate data from a conditional distribution, and
haven't been able to modify my existing code to do so. I searched
the archives, but didn't find any previous post that matched my
question.
n=10000
pop = data.frame(W1 = rbinom(n, 1, .2),
W2 = runif(n, min = 3, max = 8), W3 = rnorm(n, mean=0, sd=2))
pop = transform(pop,
A = rbinom(n, 1,