[R] difference in results from R vs SPSS

Fiona Sammut fiona.sammut at um.edu.mt
Sat Jun 24 13:51:36 CEST 2006

Thanks for the reply.  The mistake in 1 resulted to be due to using a 
different number of decimal places in the data. 

As regards 2, will check it out again.

Thanks again.

> Fiona Sammut wrote:
>> Hi all,
>> 1.  I am doing some data analysis using both R and SPSS, to get used 
>> to both software packages.  I had performed linear regression in R 
>> and SPSS for a number of times before this last one and the resulting 
>> coefficient values always matched.  However, this last data set I was 
>> analyzing using simple linear regression and using the command 
>> lm(y~x), gave me different readings from R and SPSS:
>> R:                y= 33.803 + 6.897x
>> SPSS:             y= 47.589 + 6.263x
>> I have no doubts regarding the procedure employed in SPSS and I am 
>> sure I am using the same dataset for both software packages.
>   My guess is you have missing values defined in SPSS but don't have 
> those same values set to NA in R.  Have you requested basic 
> descriptive statistics in both programs and found that they match?  
> Also, perhaps x a factor in R.  If so, how are its contrasts set?
>> 2.  Correct me if I am wrong, but from what I've read, it seems that 
>> the command /anova /in R works out an analysis of variance without 
>> including the intercept.  Is that so?  Cause again I am working out 
>> an anova in R and SPSS and I got different resulting sums of squares 
>> and different degrees of freedom.  I thought this was because one 
>> package is working with an intercept and the other isn't.
>   I don't think this has anything to do with the discrepancy.
>> Can anyone enlighten me as to what might have happened in both 1. and 
>> 2. please?  Are they both due to my poor knowledge of R or could 
>> occurences as above happen?
>> 3.  I would like a reference to a command which can be used to fit a 
>> distribution to a disrete distribution.
> library(MASS)
> ?fitdistr
>> Thanks in advance for your consideration.
>> - Fiona Sammut
>> ------------------------------------------------------------------------
>> ______________________________________________
>> R-help at stat.math.ethz.ch mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide! 
>> http://www.R-project.org/posting-guide.html

More information about the R-help mailing list