Displaying 20 results from an estimated 200 matches similar to: "can optimize solve paired euqations?"
2007 Dec 17
2
can R solve these paired equations
Dear:
I have a paired equation below. Can I solve (x,y) using R.
Thanks!
Xin
A=327.727
B=9517.336
p=0.114^10
(1-p)*y*(1-x)/x/(1-x^y)=A
A(1+(1-x)*(1+y)/x-A))=B
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2007 Jun 20
4
finding roots of multivariate equation
Hello,
I want to find the roots of an equation in two variables. I am aware of the
uniroot function, which can do this for a function with a single variable (as I
understand it...) but cannot find a function that does this for an equation
with more than one variable. I am looking for something implementing similar
to a Newton-Raphson algorithm.
Thanks.
--
Bill Shipley
North American Editor for
2006 Jan 19
1
empirical maximum likelihood estimation
Dear R-users
Problem:
Given the following system of ordinary differential euqations
dM/dt = (-n)*M-h*M
dS/dt = n*M-h*S+u*R
dA/dt = h*S-q*A
dI/dt = q*A-p*I
dJ/dt = h*M-v*J
dR/dt=p*I+v*J-u*R
where M,S,A,I,J,R are state variables and n,h,u,q,p,v parameters.
I'm able to calculate the likelihood value based on the solutions
M,S,A,I,J,R of the ODE's given the data, but without an explicit
2004 Feb 22
1
Shell scripts broken in klibc-0.114
In klibc-0.114, any shell script like this:
======================================================================
#!/path/to/klibc-0.114/ash/sh
echo hi
======================================================================
...elicits the following error when executed:
/var/tmp/hack.sh: Can't open /var/tmp/hack.sh
Running under strace, I get:
execve("/var/tmp/hack.sh",
2011 Jun 08
2
Results of CFA with Lavaan
I've just found the lavaan package, and I really appreciate it, as it
seems to succeed with models that were failing in sem::sem. I need
some clarification, however, in the output, and I was hoping the list
could help me.
I'll go with the standard example from the help documentation, as my
problem is much larger but no more complicated than that.
My question is, why is there one latent
2004 Jan 12
1
extract data from a data.frame
Hi,
I'm reading part of a table from postgres, so I'm
getting a data frame.
how can I extract the numerica values so I can
operate on them.
> res <- dbGetResult(mydata)
> str(res)
`data.frame': 5 obs. of 8 variables:
$ cyx.1: num 0.149 -0.278 0.114 0.060 0.109
$ cyx.2: num 0.158 -0.070 0.063 0.149 0.150
$ cyx.3: num 0.052 -0.350 0.114 0.126 0.238
2011 Jan 26
2
write.table -- maintain decimal places
Hello, All,
How can I maintain the decimal places when using write.table()?
Jim
e.g.
df:
EFFECT2 PVALUE
1 0.023 0.88080
2 -0.260 0.08641
3 -0.114 0.45200
write.table(df,file='df.txt',quote=F,sep='\t',row.names=F)
df.txt:
EFFECT2 PVALUE
0.023 0.8808
-0.26 0.08641
-0.114 0.452
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2010 Feb 17
2
extract the data that match
Hi r-users,
I would like to extract the data that match. Attached is my data:
I'm interested in matchind the value in column 'intg' with value in column 'rand_no'
> cbind(z=z,intg=dd,rand_no = rr)
z intg rand_no
[1,] 0.00 0.000 0.001
[2,] 0.01 0.000 0.002
[3,] 0.02 0.000 0.002
[4,] 0.03 0.000 0.003
[5,] 0.04 0.000 0.003
[6,]
2010 Oct 29
1
About ping latency in SR-IOV
Hi, Greg, Eddie,
I found that in SR-IOV + HVM environment, ping latency depends on ping interval.
The NIC is Intel 82576 (1000Mbps), server uses xen-4.0.1, domain-0 is
kernel-2.6.32
and HVM is kernel-2.6.31. The server and client are connected through
a 1000Mbps switch.
The data is as following:
# ping -i 1 192.168.0.21
PING 192.168.0.21 (192.168.0.21) 56(84) bytes of data.
64 bytes from
2004 Feb 22
3
ARM/Thumb updates and some other minor tweaks
The attached patches are against the v0.114 release and cover some of
the tweaks I made while playing about testing ARM and Thumb support.
Please review and consider applying.
Even with the patches, ARM dynamic linking doesn't seem to work and
the Thumb test applications seem to have shaken out a Thumb bug in
the 2.4.21-rmk2 kernel which I'm still trying to track down. Still
more fun to
2011 Jan 20
2
reading in time series
This is causing me great consternation, and I've spent too much time
floundering around on it.
My data is in the form of columns in Excel, with the first column being in
m/dd/yyyy hh:mm format. The spreadsheet is complicated (headers, merged
cells, lines w/o data); so I've tried various ways of exporting the data
into a text file for the R processing - CSV, spaced, etc. For example:
2006 Jul 19
2
Stirling numbers
Hi
anyone coded up Stirling numbers in R?
[I need unsigned Stirling numbers of the first kind]
cheers
Robin
--
Robin Hankin
Uncertainty Analyst
National Oceanography Centre, Southampton
European Way, Southampton SO14 3ZH, UK
tel 023-8059-7743
2012 Jun 13
2
asign variables in a "for" loop
Dear R-helpers,
I'm stuck with a little problem that surely has an easy solution but I
can't think of a way to solve it. I'd really appreciate any help you can
offer me!
I'll provide a small example. Given a dataframe data.txt that looks like
this:
ID freq Var Var_mean Ratio_mean Var_median
Ratio_median Var_sum Ratio_min Var_max Ratio_max Var_min
2009 Nov 03
1
How to display full name for the coefficients/factors in summary()?
Hi,
I am wondering if there is a way to display the full anme of the
regression coeffients/factors in the summary?
Suppose I have a bogus data set using weekday as factor which has 7 levels
such as:
mydata <- sample(364)
wk <- rep(1:7, 52)
weekday <-
2009 Aug 02
1
Competing Risks Regression with qualitative predictor with more than 2 categories
Hello,
I have a question regarding competing risk regression using cmprsk package (function crr()). I am using R2.9.1. How can I do to assess the effect of qualitative predictor (gg) with more than two categories (a,b,c) categorie c is the reference category. See above results, gg is considered like a ordered predictor !
Thank you for your help
Jan
> # simulated data to test
> set.seed(10)
2010 Feb 04
2
help needed using t.test with factors
I am trying to use t.test on the following data:
date type INTERVAL nCASES MTF SDF MTO SDO
nFST MF nOBS MO MB BIASCV BIASEV ME MAE
RMSE CRCF
2001-06-15 avn GE1.00 4385 0.246 0.300 1.502
0.556 1367 1.373 4385 1.502 1.471 0.285 0.164
-1.256 1.266 1.399 0.056
2001-06-15 avn
2004 Jun 11
4
Regression query
Hi
I have a set of data with both quantitative and categorical predictors.
After scaling of response variable, i looked for multicollinearity (VIF
values)
among the predictors and removed the predictors who were hinding some of the
other significant
predictors. I'm curious to know whether the predictors (who are not
significant)
while doing simple 'lm' will be involved in
2005 Aug 08
2
extract t-values from pairwise.t.test
Hi,
how can I extract the t-values after running a pairwise.t.test? The
output just list the p-values.
Many thanks for your help.
Cheers
Guido
____________________________________
Guido J. Parra
School of Tropical Environment Studies and Geography
James Cook University
Townsville
Queensland 4811
Phone: 61 7 47815824
Fax: 61 7 47814020
Mobile: 0437630843
e-mail:
2006 May 15
1
anova statistics in lmer
Dear list members,
I am new to R and to the R-help list. I am trying to perform a
mixed-model analysis using the lmer() function. I have a problem with
the output anova table when using the anova() function on the lmer
output object: I only get the numerator d.f., the sum of squares and the
mean squares, but not the denominator d.f., F statistics and P values.
Below is a sample output, following
2007 Mar 18
1
HELP...Running data
We are two french students and we have a problem concerning an exercize.
We don't know how to resolve it.
It would be fantastic if someone can help us.
Thanks.
Description:
This study examined how the metabolic cost of locomotion varied
with speed, stride frequency and body mass. Cost was determined
by measuring oxygen consumption (?vo2?), analyzing the oxygen
content in air inhaled and