Re: [R] Difference in cummulative variance depending on print command

2014-12-07 Thread William Revelle
Dear Rena,

As Peter points out, it is better to ask the maintainer of the program for 
detailed questions.  

  As Peter correctly surmised, print.psych (which is used to print the output 
from the fa function), knows that you have an oblique solution and is reporting 
the amount of variance associated with the oblique factors (taking into account 
that they are correlated).  The default print method assumes orthogonal factors.

If you compare the total amount of variance accounted for (cumulative Var) for 
all of the factors (.59) , this will match that found using orthogonal 
rotations, while the default print method of the loadings does not.

Bill

 On Dec 6, 2014, at 10:48 AM, peter dalgaard pda...@gmail.com wrote:
 
 Firstly, there is no fa() function in base R. There is one in package 
 psych(), which has a maintainer, etc.
 
 I guess that it is because fa() does a non-orthogonal factor rotation and its 
 print method knows about it, whereas the default print method for loadings 
 assumes that rotations are orthogonal.
 
 - Peter D.
 
 On 05 Dec 2014, at 13:28 , Rena Büsch rena.bue...@gmx.de wrote:
 
 Hello,
 I am trying a factor analysis via R.
 When running the pricipal axis analysis I do get different tables depending
 on the print command.
 This is my factor analysis:
 fa.pa_cor_3_2- fa(ItemsCor_4, nfactors=3, fm=pa,rotate=oblimin)
 
 To get the h2 I did the following print command:
 print (fa.pa_cor_3_2, digits=2, cut=.3, sort=T)
 To just get the loadings I did the following print command:
 print (fa.pa_cor_3_2$loadings, digits=2, cutoff=.3, sort=T)
 
 The result of the first print is the following Eigenvalue-cumulative
 variance table:
   PA1   PA2  PA3
 SS loadings20.59 18.16 5.03
 Proportion Var  0.28  0.25 0.07
 Cumulative Var  0.28  0.52 0.59
 
 With the second print command I get a different table:
   PA1   PA2  PA3
 SS loadings17.63 15.12 3.14
 Proportion Var  0.24  0.20 0.04
 Cumulative Var  0.24  0.44 0.49
 
 The loadings are the same for both commands. There is just this slight
 difference in the cumulative Var.
 
 Does anyone have an idea of a cause for the difference? What can I report?
 Did I post enough information to fully understand my problem?
 Thanks in Advance
 Rena
 
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 -- 
 Peter Dalgaard, Professor,
 Center for Statistics, Copenhagen Business School
 Solbjerg Plads 3, 2000 Frederiksberg, Denmark
 Phone: (+45)38153501
 Email: pd@cbs.dk  Priv: pda...@gmail.com
 
 __
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William Revellehttp://personality-project.org/revelle.html
Professor  http://personality-project.org
Department of Psychology   http://www.wcas.northwestern.edu/psych/
Northwestern Universityhttp://www.northwestern.edu/
Use R for psychology http://personality-project.org/r
It is 5 minutes to midnighthttp://www.thebulletin.org

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Re: [R] Difference in cummulative variance depending on print command

2014-12-06 Thread peter dalgaard
Firstly, there is no fa() function in base R. There is one in package psych(), 
which has a maintainer, etc.

I guess that it is because fa() does a non-orthogonal factor rotation and its 
print method knows about it, whereas the default print method for loadings 
assumes that rotations are orthogonal.

- Peter D.

 On 05 Dec 2014, at 13:28 , Rena Büsch rena.bue...@gmx.de wrote:
 
 Hello,
 I am trying a factor analysis via R.
 When running the pricipal axis analysis I do get different tables depending
 on the print command.
 This is my factor analysis:
 fa.pa_cor_3_2- fa(ItemsCor_4, nfactors=3, fm=pa,rotate=oblimin)
 
 To get the h2 I did the following print command:
 print (fa.pa_cor_3_2, digits=2, cut=.3, sort=T)
 To just get the loadings I did the following print command:
 print (fa.pa_cor_3_2$loadings, digits=2, cutoff=.3, sort=T)
 
 The result of the first print is the following Eigenvalue-cumulative
 variance table:
PA1   PA2  PA3
 SS loadings20.59 18.16 5.03
 Proportion Var  0.28  0.25 0.07
 Cumulative Var  0.28  0.52 0.59
 
 With the second print command I get a different table:
PA1   PA2  PA3
 SS loadings17.63 15.12 3.14
 Proportion Var  0.24  0.20 0.04
 Cumulative Var  0.24  0.44 0.49
 
 The loadings are the same for both commands. There is just this slight
 difference in the cumulative Var.
 
 Does anyone have an idea of a cause for the difference? What can I report?
 Did I post enough information to fully understand my problem?
 Thanks in Advance
 Rena
 
 __
 R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
 and provide commented, minimal, self-contained, reproducible code.

-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd@cbs.dk  Priv: pda...@gmail.com

__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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and provide commented, minimal, self-contained, reproducible code.


[R] Difference in cummulative variance depending on print command

2014-12-05 Thread Rena Büsch

Hello,
I am trying a factor analysis via R.
When running the pricipal axis analysis I do get different tables depending
on the print command.
This is my factor analysis:
fa.pa_cor_3_2- fa(ItemsCor_4, nfactors=3, fm=pa,rotate=oblimin)

To get the h2 I did the following print command:
print (fa.pa_cor_3_2, digits=2, cut=.3, sort=T)
To just get the loadings I did the following print command:
print (fa.pa_cor_3_2$loadings, digits=2, cutoff=.3, sort=T)

The result of the first print is the following Eigenvalue-cumulative
variance table:
PA1   PA2  PA3
SS loadings20.59 18.16 5.03
Proportion Var  0.28  0.25 0.07
Cumulative Var  0.28  0.52 0.59

With the second print command I get a different table:
PA1   PA2  PA3
SS loadings17.63 15.12 3.14
Proportion Var  0.24  0.20 0.04
Cumulative Var  0.24  0.44 0.49

The loadings are the same for both commands. There is just this slight
difference in the cumulative Var.

Does anyone have an idea of a cause for the difference? What can I report?
Did I post enough information to fully understand my problem?
Thanks in Advance
Rena

__
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.