Displaying 20 results from an estimated 5000 matches similar to: "Confidence interval calculation for intersection of two quadratic lines"
2009 Sep 18
1
merging data frames with matrix objects when missing cases
Hi,
I have faced a problem with the merge() function when trying to merge
two data frames that have a common index but the second one does not
have cases for all indexes in the first one. With usual variables R
fills in the missing cases with NA if all=T is requested. But if the
variable is a matrix R seems to insert NA only to the first column of
the matrix and fill in the rest of the columns by
2017 Jul 16
0
How to formulate quadratic function with interaction terms for the PLS fitting model?
??
If I haven't misunderstood, they are completely different!
1) NIR must be a matrix, or poly(NIR,...) will fail.
2) Due to the previously identified bug in poly, degree must be
explicitly given as poly(NIR, degree =2,raw = TRUE).
Now consider the following example:
> df <-matrix(runif(60),ncol=3)
> y <- runif(20)
> mdl1 <-lm(y~df*I(df^2))
> mdl2
2010 Aug 10
3
grep problem decimal points looping
Hi R Users,
I have been trying to work out how to rename column names using grep,
basically I have generated these column names using tapply:
[1] "NAME" "X1.1" "X2.1" "X3.1" "X4.1" "X5.1" "X6.1" "X7.1" "X8.1"
[10] "X1.2" "X2.2" "X3.2" "X4.2"
2017 Jul 16
2
How to formulate quadratic function with interaction terms for the PLS fitting model?
> On Jul 13, 2017, at 7:43 AM, Bert Gunter <bgunter.4567 at gmail.com> wrote:
>
> Below.
>
> -- Bert
> Bert Gunter
>
>
>
> On Thu, Jul 13, 2017 at 3:07 AM, Luigi Biagini <luigi.biagini at gmail.com> wrote:
>> I have two ideas about it.
>>
>> 1-
>> i) Entering variables in quadratic form is done with the command I
>>
2003 Jan 21
1
(v2) quadratic trends and changes in slopes (R-help digest, Vol 1 #52 - 16 msgs)
-----Original Message-----
Message: 6
Date: Mon, 20 Jan 2003 01:11:24 +0100
From: Martin Michlmayr <tbm at cyrius.com>
To: r-help at stat.math.ethz.ch
Subject: [R] quadratic trends and changes in slopes
I'd like to use linear and quadratic trend analysis in order to find
out a change in slope. Basically, I need to solve a similar problem as
discussed in
2004 Oct 06
0
quadratically constrained quadratic programming
Hi,
Does anybody have experience to solve an quadratic programming problem
with quadratic constraints in R?
It seems that the package "quadprog" only handles the quadratic
programming with linear constraint. My probelm is to maximze
x^T\Sigma_{xy} y,
subject to x^Tx=1, y^T\Sigma_{yy} y=1, and sum(y)<t, or sum(y)=t, where
x and y are the variable, and the Sigma's and t are
2009 Sep 20
2
Quadratic Constraints
HI All,
I am unable to solve a optimization Problem Please Help Me out of this to
solve. The Optimization problem is as follows :-
My objective function is linear and one of the constraint is quadratic.
Min z = 5 * X1 + 9* X2 + 7.15 *X3 + 2 * X4
subject to
X1 + X2 + X3 +X4 = 9
X1 + X4 < = 6.55
X3(X3 - 3.5) >=0
X1,X2,X3,X4 >=0
Now the problem is how to solve this kind of
2012 Jan 02
2
quadratic programming-maximization instead of minization
Hi, I need to maximize a quadratic function under constraints in R.
For minimization I used solve.QP but for maximization it is not useful since
the matrix D of the quadratic function
should be positive definite hence I cannot simply change the sign.
any suggestion ?
thanks
--
View this message in context:
2012 Aug 03
0
Binary Quadratic Opt
Hi Bert,
I won't post any more messages on this thread as problem has shifted from Optimization in R to Graph Algorithms.
Rest fine
Khris.
On Aug 2, 2012, at 9:13 PM, Bert Gunter [via R] wrote:
> This discussion needs to be taken off (this) list, as it appears to
> have nothing to do with R.
>
> -- Bert
>
> On Thu, Aug 2, 2012 at 2:27 AM, khris <[hidden email]>
2007 Dec 22
1
using solve.qp without a quadratic term
I was playing around with a simple example using solve.qp ( function is in the quadprog package ) and the code is below. ( I'm not even sure there if there is a reasonable solution because I made the problem up ).
But, when I try to use solve.QP to solve it, I get the error that D in the quadratic function is not positive
definite. This is because Dmat is zero
because I don't have a
2009 Mar 27
0
Quadratic Discriminant Analysis (qda)
Hi listers,
Does anybody knows if the function qda for quadratic discriminant analysis
provides the coefficients of quadratic discriminants...
Well, I find out that for the linear discriminant analysis lda, the fonction
provides the coefficients...
Thanks in advance,
Marcio
--
View this message in context: http://www.nabble.com/Quadratic-Discriminant-Analysis-%28qda%29-tp22747647p22747647.html
2003 Jan 20
0
quadratic trends and changes in slopes (R-help digest, Vol 1 #52 - 16 msgs)
-----Original Message-----
Message: 6
Date: Mon, 20 Jan 2003 01:11:24 +0100
From: Martin Michlmayr <tbm at cyrius.com>
To: r-help at stat.math.ethz.ch
Subject: [R] quadratic trends and changes in slopes
I'd like to use linear and quadratic trend analysis in order to find
out a change in slope. Basically, I need to solve a similar problem as
discussed in
2008 Apr 02
0
Using file to handle a direcoty, recurse question.
Alright, going ot ask this question in advance of doing bone headed
tests. I have one application that does not understand the idea of
/usr/local/ and insists on populating /usr. Of course it is closed
source and commercial and it is the one they want to use. Below is the
list of junk it shoves in /usr/share. Between the Type Reference guide
and another email , I believe I can move this tree
2012 Jun 13
3
How to plot linear, cubic and quadratic fitting curve in a figure?
Hi R experts,
Could you please help me to fit a linear, cubic and quadratic curve in a figure? I was trying to show all these three fitting curves with different colour in one figure.
I spent substantial time to figure it out, but I could not.
I have given here a example and what I did for linear, but no idea for cubic and quadratic fitting curve
> dput(test)
structure(list(sp = c(4L, 5L,
2010 Dec 04
1
Quadratic programming with semi-definite matrix
Hello.
I'm trying to solve a quadratic programming problem of the form min
||Hx - y||^2 s.t. x >= 0 and x <= t using solve.QP in the quadprog
package but I'm having problems with Dmat not being positive definite,
which is kinda okay since I expect it to be numerically semi-definite
in most cases. As far as I'm aware the problem arises because the
Goldfarb and Idnani method first
2008 May 12
1
Quadratic Constraints
Hi R,
A quick question.... How can I optimize the objective function
constrained to quadratic constraints? Which function of R is useful for
quadratic constraints?
Many Thanks,
Shubha
This e-mail may contain confidential and/or privileged i...{{dropped:13}}
2008 May 22
1
Plotting a Quadratic...
I have an equation describing the best-fit model for a set of points (just 2
axes) that is in the form:
y=b+mx+px^2
Where b is the intercept, m is the slope describing a linear term, and p is
a slope of the quadratic term.
I would like to plot this equation on a curve (I know the equation is
y=(.1766x^2)+(.171x)+.101) on the original scatterplot. Any easy way to plot
this equation and
2013 May 03
1
R package for bootstrapping (comparing two quadratic regression models)
Hello ,
I want to compare two quadratic regression models with non-parametric
bootstrap.
However, I do not know which R package can serve the purpose,
such as boot, rms, or bootstrap, DeltaR.
Please kindly advise and thank you.
Elaine
The two quadratic regression models are
y1=a1x^2+b1x+c1
y1= observed migration distance of butterflies()
y2=a2x^2+b2x+c2
y2= predicted migration distance of
2009 Oct 05
2
How to plot a Quadratic Model?
Good day for all,
I'm a beginner aRgonaut, thus I'm having a problem to plot a quadratic model
of regression in a plot.
First I wrote:
>plot(Y~X)
and then I tried:
>abline(lm(Y~X+I(X^2))
but "abline" only uses the first two of three regression coefficients, thus
I tried:
>line(lm(Y~X+I(X^2))
but a message error is showed ("insufficient observations").
2007 Jul 11
0
Some questions about quadratic programming (QP)
Dear R Users ,
As a beginner in QP, I'm trying to solve a Support Vector Machine problem by a QP. In particulare I am using the quadprog package.
My questions are here:
1- In the document for the package (The quadprog Package), the inequality constraint is mentioned with >= , however in a standard QP, this usaully is written with <= . This constraint should be multiplied by a