Displaying 20 results from an estimated 10000 matches similar to: "discriminant analysis"
2004 Jan 20
1
evaluation of discriminant functions+multivariate homoscedasticity
Hello,
I am switching from SPSS-Windows to R-Linux. My university is very
SPSS-oriented so maybe that's the cause of my problems. I am a beginner
in R and my assignments are SPSS-oriented, so I hope I don't annoy
anyone with my questions...
Right now I've got 2 problems:
-I have to evaluate discriminant functions I have calculated with
lda(MASS). I can't find a measure that
2004 Jan 20
1
evaluation of discriminant functions+multivariate homosce dasticity
While I don't know anything about Box's M test, I googled around and found a
Matlab M-file that computes it. Below is my straight-forward translation of
the code, without knowing Matlab or the formula (and done in a few minutes).
I hope this demonstrates one of Prof. Ripley's point: If you really want to
shoot yourself in the foot, you can probably program R to do that for you.
[BTW:
2009 Oct 23
3
reset par() within plot layout
Dear list,
I would like to produce a matrix of plots, where par() is reset after
each plot (see below [simplified] example). When I use layout() to do
so, I seem to also reset the layout. I have not been able to figure out
how to prevent this from happening.
Any help is greatly appreciated!
Janke
Example code:
#Desired result is a layout of 2 plots: one red and one black
layout(matrix(1:2,
2009 Aug 20
0
Canonical Discriminant Function Analysis
Dear R users:
Could you please help me out how to use R to get and interpret
Standardized discriminant functions and structure coefficients for sex,
Degree_Program, and Enrol_USM
Please find the data file at:
http://www.usm.maine.edu/~aaboueissa/Rhelps/Rhelps.html
data files are (xls file: dataforRxls or txt file: dataforRtxt)
Output looks like this table.
Standardized
2010 Apr 13
0
Wilks lamda and single discriminant function
Dear R-users,
I'm wondering how to obtain Wilks-lambda values when discriminant
analyses have only one discriminant function (i.e. 2 categories to
discriminate between).
The use of manova(predictions~groups, test="Wilks") asks for multiple
response and the use of anova(lm(predictions~groups), test="Wilks")
simply does not consider the last term.
(The alternative
2011 Mar 12
1
Stepwise Discriminant... in R
Hello R list,
I'm looking to do some stepwise discriminant function analysis (DFA) based
on the minimization of Wilks' lambda in R to end up with a composite
signature (of metals "Al","Sb","Bi","Cr","Ba") capable of discriminating
100% of the source factors (LANDUSE: "A","B","C").
The Wilks' lambda
2005 Jul 10
2
Off topic -2 Ln Lambda and Chi square
Dear R :
Sorry for the off topic question, but does anyone know the reference for
the -2 Ln Lambda following a Chi Square distribution, please?
Possibly one of Bartlett's?
Thanks in advance!
Sincerely,
Laura Holt
mailto: lauraholt_983 at hotmail.com
2009 May 24
1
Animal Morphology: Deriving Classification Equation with Linear Discriminat Analysis (lda)
Fellow R Users:
I'm not extremely familiar with lda or R programming, but a recent editorial
review of a manuscript submission has prompted a crash cousre. I am on this
forum hoping I could solicit some much needed advice for deriving a
classification equation.
I have used three basic measurements in lda to predict two groups: male and
female. I have a working model, low Wilk's lambda,
2009 Apr 25
1
Request for some help
Dera Graham
I would highly be thankful if u help me how to do 1. Wilk's Lambda test
2. Box plots and 3. pooled within group standardization in discriminant
analysis with 6 variables in R. Actually I am new to R but I have an
assignment to analyse some questions only in R and there is drawback for me,
no one in our dept. knows about R. Really I am very much depressed and
afraid that I will
2012 Jun 19
1
Stepwise Discriminant Analysis - greedy.wilks
I don't understand which is the problem
Could you help me please?
Thanks in advance
Marta
> str(data_indiciN2)
'data.frame': 200 obs. of 36 variables:
$ gruppo: Factor w/ 2 levels "0","1": 2 2 2 2 2 2 2 2 2 2 ...
$ I001N2: num 19.32 8.22 28.35 7.24 14.7 ...
$ I002N2: num 2.92 2.54 0.11 1.6 7.12 ...
$ I003N2: num -22.362 -0.222 -19.291
2005 Sep 29
1
Fisher's discriminant functions
Hi everyone,
I'm trying to solve a problem about how to get the
Fisher's discriminant functions of a "lda" (linear
discriminant analysis) object, I mean, the object
obtained from doing "lda(formula, data)" function of
the package MASS in R-project. This object gives me
the canonical linear functions (n-1 coefficients
matrix of n groups at least), and only with this
2004 Dec 01
0
[Fwd: Re: Kernel Fisher Discriminant in R?]
Ooops...I meant "formulations shouldn't be difficult"
-------- Original Message --------
Subject: Re: [R] Kernel Fisher Discriminant in R?
Date: Wed, 01 Dec 2004 08:05:38 +0200
From: Gorden Jemwa <jemwa at sun.ac.za>
To: huh at rti.org
CC: r-help at stat.math.ethz.ch
You could us the kernlab package as a building block. Implementation of
Kernel Fisher Discriminant Analysis
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 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
2005 Apr 08
0
Using Flexible Discriminant Analysis (fda) in mda
Greetings everyone,
I was wondering if anyone had experience in using fda (flexible discriminant analysis) in the mda package. Specifically, I can run the model but I cant locate/produce much of anything beyond the predicted values and confusion matrix. I've been searching for more examples or documentation but cant seem to locate any specific to the program itself.
I need to be able to find
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 Aug 05
1
lda discriminant functions
Hi list,
I'm looking about lda function.
I'd like to know how calcolate the value of the discriminant functions for the
original datas.
I see that in the result object "lda" there is $scaling a matrix which
transforms observations to discriminant functions, normalized so that within
groups covariance matrix is spherical.
I'd like to have the value of the discriminant
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
2005 Jul 05
4
Discriminant Function Analysis
Dear All
This is more of a statistics question than a question about help for R,
so forgive me.
I am using lda from the MASS package to perform linear discriminant
function analysis. I have 14 cases belonging to two groups and have
measured each of 37 variables. I want to find those variables that best
discriminate between the two groups, and I want to visualise that and
create a
2002 Mar 17
1
Discriminant Analysis Using Anova in R
Hi All,
I am currently trying to use R to perform some statistical discriminant
analysis on a data set using ANOVA. I'm new to anova and R as well. As I
understand it, ANOVA can be used to perform discriminant analysis by
measuring the value of the f-test when given a data set with a grouping
variable and the dependent variable. What I would like to do in R is perform
ANOVA and extract the