[R] Unequal column lengths

[John Kane]

Many basic summary stats in R will not work (i.e. usually return an NA) if there are NAs in the data unless you explicitylauthorize it to do so.

With your data set df
with(df, mean(Dat2, na.rm = TRUE))
[1] 5

This by the way is functionally the same as 
mean(df$Dat2, na.rm = TRUE) 
It's just easier to type the first one 


In other cases R will do not object to the NA's

summary(df)
     Dat1          Dat2        Dat3     
 Min.   :1.0   Min.   :3   Min.   :4.00  
 1st Qu.:2.0   1st Qu.:4   1st Qu.:4.75  
 Median :3.0   Median :5   Median :5.00  
 Mean   :4.4   Mean   :5   Mean   :5.75  
 3rd Qu.:7.0   3rd Qu.:6   3rd Qu.:6.00  
 Max.   :9.0   Max.   :7   Max.   :9.00  
               NA's   :2   NA's   :1     


John Kane
Kingston ON Canada


> -----Original Message-----
> From: tom at vims.edu
> Sent: Thu, 14 Apr 2016 21:33:31 +0000
> To: r-help at r-project.org
> Subject: [R] Unequal column lengths
> 
> Hello,
> 
> Ive tried several times to learn R, but have never gotten past a
> particular gate.  My data are organized by column in Excel, with column
> headers in the first row.  The columns are of unequal lengths.  I export
> them as CSV, then import the CSV file into R.  I wish to summarize the
> data by column.  R inserts NA for missing values, then refuses to operate
> on columns with NA.  R is importing my data into a data frame, and I
> realize that is inappropriate for what I want to do.
> 
> How can I import my data so that I can work on columns of unequal length?
> The first thing I would like to do is generate a table containing mean,
> median, mode, standard deviation, min, max and count, all per column.
> 
> Thank you, Tom
> 
> Example data
>   Dat1 Dat2 Dat3
> 1    1    5    4
> 2    7    7    9
> 3    3    3    5
> 4    2   NA  5
> 5    9   NA NA
> 
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> 
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