Displaying 20 results from an estimated 5000 matches similar to: "conflicting results on NA in a qda predicted object:"
2003 May 22
1
Getting the Bootstrap Error Rate of QDA
Hi,
What does this mean when I have something like:
> qda.boot <- boot(train, qda.bootstrap, R = 500)
Error in qda.default(structure(data.matrix(x), class = "matrix"), ...) :
Rank deficiency in group M
with my qda.bootstrap() looks something like:
> qda.bootstrap <- function(data, index) {
+ boot.qda <- qda(x = data[index, 2:9], group = data[index, 1])
+ qda.pred
2004 Jan 19
1
qda problem
Hi,
the following strange error appears when I use qda:
> qda1 <- qda(as.data.frame(mfilters[cvtrain,]),as.factor(traingroups))
Error: function is not a closure
That's also strange:
> qda1 <- qda(mfilters[cvtrain,],as.factor(traingroups))
Error in qda.default(mfilters[cvtrain, ], as.factor(traingroups)) :
length of dimnames must match that of dims
Some backgroud:
>
2003 Nov 15
1
Loading file to use with qda()
z <- qda(train, cl)
save(z, file = "qda.dat")
load("qda.dat")
predict(qda.dat, test)$class
I'm trying to save z where z <-qda(train, cl) and load z for later use in predict(z, test)$class.
I think I successfully saved z by save(z, file = "qda.dat") but when I tried to load by load("qda.dat") and
call predict(qda.dat, test)$class, it gives me error
2017 Aug 23
0
Scaling Matrix in qda() function in MASS package
You need to learn how to access code for nonexported methods. See ? "::"
> methods(qda)
[1] qda.data.frame* qda.default* qda.formula* qda.matrix*
see '?methods' for accessing help and source code
Shows you that the methods are not exported from the namespace. Hence
you need to use the triple colon operator to see their code:
> MASS:::qda
Once you have the code, I
2007 Jul 25
1
qda(MASS) function error
Dear R user,
I'm using qda (quadratic discriminant analysis) function (package
MASS) to classify 58 explanatory variables (numeric type with different
ranges) using a grouping variable (factor 2 levels "0" "1"). I'm using
the qda method for class 'data.frame' (in this way I don't need to
specify a formula).
Using the function:
2017 Aug 24
1
Scaling Matrix in qda() function in MASS package
I guess the question that is being asked here is what is the scaling matrix that is being returned in the qda object. The help file on qda() says:
...
scaling: for each group ?i?, ?scaling[,,i]? is an array which transforms observations so that within-groups covariance matrix is spherical.
...
This is a bit ambiguous. I tried a few cases (spectral, QR decomposition, especially given that it is an
2017 Aug 23
2
Scaling Matrix in qda() function in MASS package
Hello,
I am Souradeep Chattopadhyay and I am a graduate student at Iowa
State University Department of Statistics.
Can anyone please explain the mathematical formulation behind the scaling
matrix returned by the qda function in MASS package. I want to understand
how this scaling matrix is derived from the inputs given to the qda
function.
Example Code
The following example is using
2005 Oct 22
6
wxruby.so error with weft-qda
Dear wxruby users
I''ve been trying to get wxruby-based weft-qda 0.9.6 running on a linux from
scratch 6.1 system (this list had a discussion about weft-qda last year and
alex fenton''s also been trying to help me out - no luck so far).
I get stuck with wxruby 0.60 (I think). I compiled wxruby against wxGTK 2.4.2
(without gtk2, without unicode - gtk+ version is 1.2.10) - after
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
2006 Mar 11
2
weird! QDA does not depend on priors?
Hi all,
If I run LDA on the same data (2-class classification) with default(no
priors specified in the lda function) vs. "prior=c(0.5, 0.5)", the results
are different.
The (0.5, 0.5) priors give better 1-classify-to-1 rate, and the proportional
priors(default, no priors specified in the lda function) give better
0-classify-to-0 rate, for both training and testing data sets.
However,
2003 Feb 27
2
qda plots
Hi,
I have been using some of the functions in r for classification purposes,
chiefly lda, qda, knn and nnet.
My problem is that the only one I can figure out how to represenent
graphically is lda (using plot.lda). I have tried 'fooling' this function
into accepting qda input for plotting but to no avail. I wonder if you have
any suggestions?
Thanks alot,
Anne Marie Power
Marine lab.
2004 Jul 03
1
graphic representation of a qda object
Hi,
I'm a R newbie and I have a supervised 2-class classification problem.
To find out the best representation of my data (dim = 45). I want to perform LDA und QDA on the diffrent data representations to find out, which is best to discriminate the 2 sets. For LDA there exists a method plot.lda shows (in the 2 class case) a histogramm of the data, projected onto the linear discriminants (pleas
2007 Aug 20
2
[Weft QDA users] Weft on Ubuntu -- Ctrl-shortcuts NOT working?
Hi -- have just followed Christophe''s notes to get
Weft QDA up and running on my IBM Thinkpad T20
w/Ubuntu 6.06 (Dapper Drake).
Am just going thru the manual and trying various
things, as I''m new to qualitative analysis AND new to
QDA tools.
Anyway, one thing I''ve found is that many (and maybe
ALL?) of the CTRL-shortcuts mentioned in the
documentation are not working
2010 Dec 07
9
[Weft QDA users] working on team using weft
Hi all!
I am Angela, an Italian researcher and I am looking for an application
that allows working in team, making a shared codebook, share a text
database and code it. I tried AnSWR (the CDC''s QDA application) but its
installation is too complicated for students and it is not working on
latest version of Windows. What about Weft? Is it possible to share a
project or, at least, merge
2008 Apr 17
1
[Weft QDA users] running weft qda on mac with virtual PC
can you run weft qda on mac with virtual PC? (this is how nvivo and some others work for the mac). us poor mac users...but i commend the open source effort!
best,
Lisa
Lisa Schwartz
Language Reading and Culture
University of Arizona
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2002 May 22
1
a more specific question about qda
Perhaps, I should complement my previous e-mail question:
I am trying to select variables through a quadratic discriminant analysis.
It seems to me that a robust criterion is the value of the discriminatory
power
(i.e. the ratio of the separation of the class means to within-class
variance)
How can I obtain this ratio from V & R's qda() output ?
Thanks
(I hope this question is relevant)
--
2008 Mar 12
1
[Weft QDA users] Hello all
Hi, my name is Leandro and im Argentinian. I plan to build a web CMS
on ruby on rails, to provide CAQDAS functionality, and since im
building the site in Ruby on Rails and open source, i want to know if
Weft QDA engine is open source. If so, id would come in handy to be
able to reuse/improve an existing ruby based CAQDAS.
I''d like to emphasize the fact that i dont mean to profit from it,
2003 Jun 09
1
parameters calculated by lda and qda
Hi,
I am not sure if I remember correctly a mail last week to this messageboard
where Prof Ripley said Fisher's discriminants are not used in lda within R
and that Rao's are used instead, is this true? I looked in MASS (1996) but
I couldn't find the reference to this in chapter 12 (multivariate analysis),
the (help)lda doesn't tell me either. Could anyone tell me where can I
2004 Nov 08
7
[Fwd: Weft - a free open-source QDA tool]
Hi
Just released a first version of the WxRuby project I''ve been working
on. Firstly, I wanted to say thanks to everyone on this list who''s
helped at various points over the past year - every time I ran into a
problem someone jumped in with advice.
A very brief explanation of the app - I''m a sociologist/anthropologist
by trade, and the app is intended for use in
2011 Apr 08
2
[Weft QDA users] Shifty Markings - round 2
Good Afternoon,
I''m new to the mailing list and was wondering if anyone could help me with my current headache. I saw in the previous posts that someone else has had the problem of shifty markings. I too am finding the text immediately above what I wrote appearing in the coding reports, even though the coding in the documents themselves remains as it should. The project involves