Displaying 20 results from an estimated 2000 matches similar to: "Mark each group centroid in a linear discriminant analysis plot"
2006 Apr 04
0
Fisher's discriminant functions
Hi,
I am trying to solve a discriminant analysis in the same way as SPSS does it. I mean, given an amount of data, to train the discriminant analysis I obtain the Fisher's discriminant functions, an array of coefficients per group, so if I have 8 groups I get 8 linear functions, that allow me to operate with them easily and without a great cost of time.
My main problem is that I need to
2012 Jun 11
1
saving sublist lda object with save.image()
Greetings R experts,
I'm having some difficulty recovering lda objects that I've saved within sublists using the save.image() function. I am running a script that exports a variety of different information as a list, included within that list is an lda object. I then take that list and create a list of that with all the different replications I've run. Unfortunately I've been
2012 Oct 21
1
Linear discriminant function analysis based median as group centroid and nonparametric scale estimators???
Dear All,
I am using a specific approach for my master thesis. In essence, a
supervised reclassification is used as an intermediate step to find chemical
parameters which are able to reclassify defined groups. These variables will
be used in a next step where location and scale estimators of the groups are
important. Traditionally linear discriminant analysis is used for
reclassification which
2009 Oct 14
1
plot discriminant analysis
I'm confused on how is the right way to plot a discriminant analysis made by
lda function (MASS package).
(I had attached my data fro reproduction). When I plot a lda object :
X <- read.table("data", header=T)
lda_analysis <- lda(formula(X), data=X)
plot(lda_analysis)
#the above plot is completely different to:
plot(predict(lda_analysis)$x,
2007 Jun 18
0
discriminant analysis with lda(MASS)
I use Widows, R version 2.4.1
I have 4 questions on lda (MASS) (code is pasted below):
1st. How can I obtain the statistics and p-value associated with
discriminant analysis? Am I supposed to calculate that manually by squaring
the svd value and looking the p value up in a table? I am writing the
following code:
training.mx<-read.table('C:\\Documents and Settings\\silvia\\My
2005 Apr 28
0
Linear Discriminant Analysis Biplots
Dear R
I'm trying to plot the lda means onto a 2 D plot of discriminant scores.
Preferably I'd like these to be in a larger font compared to the
discriminant scores.
I tried
skull.mean.pred <- predict(skulls.lda, as.data.frame(skulls.lda$means),
dimen=2)
from which I got
skull.mean.pred
$class
[1] 1 2 3 4 5
Levels: 1 2 3 4 5
$posterior
1 2 3 4
2009 Nov 18
0
Y axis of 1-D Linear Discriminant Histograms
Hi all.
I would like to understand what are the units defined on the y-axis
when you plot the one-dimensional predictions (histograms) from lda()
(MASS) discriminant function objects?
While the helpfile suggests that a histogram is returned by default,
the presumably proportion-like values for each group seem to add up to
more than 1, and I'm not sure how to interpret the code from
ldahist(),
2013 Feb 20
1
Plotting Discriminants from qda
Dear R Help Members,
I am aware how to plot the LD1 vs LD2 from a lda in R, using the code:
plot(baseline.systat.hat$x, col=baseline.systat.hat$class,pch=as.numeric(baseline.systat.hat$class))
However, I need to use the quadratic discriminant function, qda due to data properties. Is there a way to obtain the same sort of plot for from a qda object (and the output of predict qda). I have not
2012 Nov 08
0
mirt vs. eRm vs. ltm vs. winsteps
Dear R-List,
I tried to fit a partial credit model using the "pcmdat" from eRm-package comparing the results of mirt, eRm, ltm and winsteps.
The results where quite different, though. I cannot figure out what went wrong and I do not know which result I can rely on.
This is what I did in R
library(mirt)
#load(file="u3.RData")
2010 Jun 06
1
I need help in analyzing
I'm sory for my weak english. I need to analyze this subject :
x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 y
0 0 1 0 0 1 0 0 1 0 czarne
1 1 0 0 0 0 1 0 0 0 rude
0 0 1 0 0 1 1 0 0 0 braz
0 0 1 0 1 0 1 0 0 0 blond
1 0 0 0 0 1 0 0 0 1 rude
1 1 0 0 0 0 0 0 0 1 blond
0 0 1 1 0 0 0 0 1 0 czarne
1 0 0 1 0 0 1 0 0 0 blond
0 0 1 0 0 1 1 0 0 0 blond
1 0 0 0 0 1 1 0 0 0 czarne
0 0 1 0 0 1 0 0 0 1 czarne
1 0 1 0 0 0
2013 Jan 01
3
translate grouped data to their centroid
Given a data set with a group factor, I want to translate the numeric
variables to their
centroid, by subtracting out the group means (adding back the grand means).
The following gives what I want, but there must be an easier way using
sweep or
apply or some such.
iris2 <- iris[,c(1,2,5)]
means <- colMeans(iris2[,1:2])
pooled <- lm(cbind(Sepal.Length, Sepal.Width) ~ Species,
2004 May 24
1
discriminant analysis
Hi,
I have done different discriminant function analysis of multivariat data. With the CV=True option I was not able to perform the predict() call. What do I have to do? Or is there no possibility at all? You also need the predicted values to produce a plot of the analysis, as far as I know.
Here my code:
pcor.lda2<-lda(pcor~habarea+hcom+isol+flowcov+herbh+inclin+windprot+shrubcov+baregr,
2015 Mar 03
3
[LLVMdev] ReduceLoadWidth, DAGCombiner and non 8bit loads/extloads question.
I'm curious about this code in ReduceLoadWidth (and in DAGCombiner in
general):
if (LegalOperations && !TLI.isLoadExtLegal(ExtType, ExtVT))
return SDValue
<http://llvm.org/docs/doxygen/html/classllvm_1_1SDValue.html>();
LegalOperations is false for the first pre-legalize pass and true for the
post-legalize pass. The first pass is target-independent yes? So that makes
sense.
2012 Aug 14
0
[LLVMdev] Load serialisation during selection DAG building
Further to my earlier question, I'm perhaps a bit confused about memory serialisation. The following example, compiled using clang for the MSP430:
target datalayout = "e-p:16:16:16-i8:8:8-i16:16:16-i32:16:32-n8:16"
target triple = "msp430-??-??"
@y = common global i16 0, align 2
@x = common global i16 0, align 2
define void @f() nounwind {
entry:
%0 = load i16* @y,
2012 Aug 14
2
[LLVMdev] Load serialisation during selection DAG building
I looked into those patches but I don't think they will help in my situation because my problems occur during instruction selection rather than scheduling.
A simple and concrete example is a pattern like:
[(set GR:$dst (add GR:$src (nvload addr:$mem)))]
where nvload matches a load provided that isVolatile() is false.
If the selection DAG looks like:
| |
LD1 LD2
^
2009 Dec 10
1
question about centroid-linkage (cluster analysis)
Dear R community,
I would be greatful if somebody could shed light on the following.
I have created a set of 6 points to check how centroid
agglomeration works in cluster analysis:
> Y <- data.frame(x=c(-1,1,1,-1,10,12),y=c(1,1,-1,-1,0,0))
It is quite intuitive to understand that the last clusters to be joined will be
{1,2,3,4} with {5,6}. Now, the centroid for the first cluster has
2008 Jul 03
1
Otpmial initial centroid in kmeans
Helo there. I am using kmeans of base package to cluster my customers. As
the results of kmeans is dependent on the initial centroid, may I know:
1) how can we specify the centroid in the R function? (I don't want random
starting pt)
2) how to determine the optimal (if not, a good) centroid to start with? (I
am not after the fixed seed solution as it only ensure that the
2015 Mar 03
2
[LLVMdev] ReduceLoadWidth, DAGCombiner and non 8bit loads/extloads question.
1) It's crashing because LD1 is produced due to LegalOperations=false in
pre-legalize pass. Then Legalization does not know how to handle it so it
asserts on a default case. I don't know if it's a reasonable expectation or
not but we do not have support for it. I have not tried
overriding shouldReduceLoadWidth.
2) I see, that makes sense to some degree, I'm curious if you can
2012 Nov 18
1
centroid of hclust
Dear UseRs,i want to find centroid of clusters, which i generated by hclust. Is there a way doing that? i took mean to elements in each cluster to get centroid but i am not sure if i am right?
thanks in advanceeliza
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2011 Jul 27
0
[LLVMdev] Avoiding load narrowing in DAGCombiner
On Wed, Jul 27, 2011 at 3:50 PM, Matt Johnson
<johnso87 at crhc.illinois.edu> wrote:
> Hi Eli,
>
> On 07/27/2011 04:59 PM, Eli Friedman wrote:
>>
>> On Wed, Jul 27, 2011 at 2:28 PM, Matt Johnson
>> <johnso87 at crhc.illinois.edu> wrote:
>>>
>>> Hi All,
>>> I'm writing a backend for a target which only supports 4-byte,