Displaying 20 results from an estimated 20000 matches similar to: "LDA newbie question"
2011 Dec 08
1
lda output missing
Hello everyone,
I am working on a linear discriminant analysis and am having issues finding
the full output of my lda. Specifically, there is no reporting of the
Proportion of Trace that is a normal output of the procedure. I'm using a
csv file and everything is reading in correctly. I've looked and looked and
can't figure out why my output is not complete. Is it something simple that
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,
2000 Apr 28
1
obtaining the discriminant line from lda
Dear R folks,
Thanks to all your help before I have loaded a 1-D toy data set into
R and did LDA on it. The toy data has Class=0 if value>0.
> XY <-- read.table ("test.xy",header=T )
> XY
X.Class value
1 0 60.4897262
2 0 32.9554489
3 -1 -53.6459189
4 0 44.4450579
.
.
.
998 -1 -43.4183157
999 0
2007 Apr 17
1
PROC DISCRIM vs. lda( ) in MASS
Hello,
I am using WinXP, R version 2.3.1, and SAS for PC version 8.1.
I have mostly used SAS over the last 4 years and would like to
compare the output of PROC DISCRIM to that of lda( ) with respect
to a very specific aspect. My data have k=3 populations and there
are 3 variates in the feature space. When using using the code
PROC DISCRIM DATA = FOO OUT = FOO_OUT OUTSTAT = FOOSTAT
2003 Apr 02
1
lda of MASS library
Hi,
it seems that the lda function in MASS library doesn''t give out the constant for the linear discriminant function under the situation that we don''t use standardized variable, anyone knows how to obtain the constant in order to construct the linear discriminant function?
I understand that if the priors are set to be 1/2, the threshold of the discriminant score used to
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 Jun 15
1
2 LDA
Hi,
I am using Partek for LDA analysis. For a binary
response variable, it generates 2 discriminant
functions, one for each of the 2 levels of the
response variable. And I can simply calculate 2
discriminant scores (say d1 and d2) for each sampples
using the 2 discriminant functions, then I can use the
following formula to compute the posterior probability
for the sample:
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 $scaling a matrix which
transforms observations to discriminant functions, normalized so that within
groups covariance matrix is spherical.
I'd like to have the value of the discriminant
2008 Dec 11
1
candisc plotting
Hello,
I have a file with two dependent variables (three and five) and one
independent variable. I do i.mod <- lm(cbind(three, five) ~ species,
data=i.txt) and get the following output:
Coefficients:
three five
(Intercept) 9.949 9.586
species -1.166 -1.156
I do a" i.can<-candisc(i.mod,data=i):
and get the following output:
Canonical Discriminant Analysis
2004 Jul 12
1
lda()
Hello,
For a simple problem with 1 predictor (x) and 2 classes (0 and 1), the
linear discriminant function should be something like
2(mu_0 - mu_1)/var x + x-independent-terms
where var is the common variance.
2010 Jun 06
1
I need help in analyzing
I'm sory for my weak english. I need to analyze this subject :
x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 y
0 0 1 0 0 1 0 0 1 0 czarne
1 1 0 0 0 0 1 0 0 0 rude
0 0 1 0 0 1 1 0 0 0 braz
0 0 1 0 1 0 1 0 0 0 blond
1 0 0 0 0 1 0 0 0 1 rude
1 1 0 0 0 0 0 0 0 1 blond
0 0 1 1 0 0 0 0 1 0 czarne
1 0 0 1 0 0 1 0 0 0 blond
0 0 1 0 0 1 1 0 0 0 blond
1 0 0 0 0 1 1 0 0 0 czarne
0 0 1 0 0 1 0 0 0 1 czarne
1 0 1 0 0 0
2000 Mar 08
3
Reading data for discriminant analysis
Dear R users,
I want to do discriminant analysis on my data. I have
successfully followed the discriminant analysis in V & R on
the iris data:
> ir <- rbind (iris3[,,1],iris3[,,2],iris3[,,3])
> ir.species <- c(rep("s",50),rep("c",50),rep("v",50))
> a <- lda(log(ir),ir.species)
> a$svd^2/sum(a$svd^2)
[1] 0.996498601 0.003501399
> a.x <-
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
2003 Apr 01
1
LDA
I used the "lda" function in the MASS library of S-Plus (R) to do a linear discriminant analysis, and got the linear coefficients, say b1 and b2 for the 2 predictors x1 and x2. I have trouble to calculate the discrimiant scores for each observation, I used 3 ways to try to repeat the scores returned by the "predict" function in S-Plus:
1. b1*x1+b2*x2
2. b1*(x1-mean of
2005 May 14
1
lda
Dear R-helpers,
if I am right a discriminant analysis can be done with "lda".
My questions are:
1. What method to discriminate the groups is used by "lda" (Fisher's linar
discriminant function, diagonal linear discriminant analysis, likelihood ratio
discriminant rule, ...)?
2. How can I see, which method is used? (Typing just lda does not give me any
code).
Thank you in
2004 Nov 02
2
lda
Hi !!
I am trying to analyze some of my data using linear discriminant analysis.
I worked out the following example code in Venables and Ripley
It does not seem to be happy with it.
============================
library(MASS)
library(stats)
data(iris3)
ir<-rbind(iris3[,,1],iris3[,,2],iris3[,,3])
ir.species<-factor(c(rep("s",50),rep("c",50),rep("v",50)))
2007 Apr 02
0
Plots from lda and predict.lda
Dear all
When plotting the results of lda and predict.lda, I expect the axis
dimensions to remain essentially the same - predict.lda projects new
observations onto linear discriminants. However, I am getting different
ranges of values along the x-axis when producing plots following each:
plot(lda) yields values in the range approximately -3 to +4, while
plot(predict.lda) yields values for the
2002 Feb 24
1
Dicsriminant coefficients
Hi! Will you please ask a newbie's question?
Need linear discriminant analysis, need to capture discrim. function
coefficiemts for further processing.
Using R ver 1.4.0 package MASS function lda()
Help says resulting object should have "components" (among others): means,
scaling, svd,
but program returns NULL for all of them
Thank you!
2010 Jul 04
2
help with predict.lda
HI, Dear community,
I am using the linear discriminant analysis to build model and make new
predictions:
> dim(train) #training data
[1] 1272 22
> dim(valid) # validation data
[1] 140 22
lda.fit <- lda(out ~ ., data=train, na.action="na.omit", CV=TRUE) # model
fitting of linear discriminant analysis on training data
> predict(lda.fit, valid) # make prediction on
2007 Aug 20
1
LDA decission boundaries
Hello,
I would like to plot the results of a LDA analysis plotting the
discriminant scores with the decission boundaries on it with rggobi. I
have GGobi already installed on my computer. I have three classes, so
the plot would be LD1xLD2 plus the decission boundaries. Here there is
the code I use make the plot:
library(MASS)
data <- zgcppr273K.pca$x[,1:7]
Tumor <-