[R] counting unique values (summary stats)

[David L Carlson]

You have several problems. As David W pointed out, there is no replace= argument in the unique() function. The first step in debugging your code should be to read the manual page for any function returning an error. Also you did not include a comma at the end of the line containing replace=TRUE. Finally the code for counting the missing values is more complicated than it needs to be. 

This code will only work if myData is a data frame that contains only columns with numeric data.

options(digits=4)
myData <- USArrests
summary.stats <- data.frame(mean=sapply(myData, mean, na.rm=TRUE), 
     sd=sapply(myData, sd, na.rm=TRUE), 
     min=sapply(myData, min, na.rm=TRUE), 
     max=sapply(myData, max, na.rm=TRUE), 
     median=sapply(myData, median, na.rm=TRUE), 
     length=sapply(myData, length),
     unique=sapply(myData, function (x) length(unique(x))),
     miss.val=sapply(myData, function(y) sum(is.na(y))))
summary.stats

            mean     sd  min   max median length unique miss.val
# Murder     7.788  4.356  0.8  17.4   7.25     50     43        0
# Assault  170.760 83.338 45.0 337.0 159.00     50     45        0
# UrbanPop  65.540 14.475 32.0  91.0  66.00     50     36        0
# Rape      21.232  9.366  7.3  46.0  20.10     50     48        0

----------------------------------------
David L Carlson
Department of Anthropology
Texas A&M University
College Station, TX 77843-4352



-----Original Message-----
From: R-help <r-help-bounces using r-project.org> On Behalf Of David Winsemius
Sent: Thursday, March 21, 2019 5:55 PM
To: reichmanj using sbcglobal.net; 'r-help mailing list' <r-help using r-project.org>
Subject: Re: [R] counting unique values (summary stats)


On 3/21/19 3:31 PM, reichmanj using sbcglobal.net wrote:
> r-help
>
> I have the following little scrip to create a df of summary stats.  I'm
> having problems obtaining the # of unique values
>
>             unique=sapply(myData, function (x)
>               length(unique(x), replace = TRUE))

I just looked up the usage on `length` and do not see any possibility of 
using a "replace" parameter. It's also unclear what sort of data object 
`myData` might be. (And you might consider using column names other than 
the names of R functions.)


-- 

David.

>
> Can I do that, or am I using the wrong R function?
>
> summary.stats <- data.frame(mean=sapply(myData, mean, na.rm=TRUE),
>             sd=sapply(myData, sd, na.rm=TRUE),
>             min=sapply(myData, min, na.rm=TRUE),
>             max=sapply(myData, max, na.rm=TRUE),
>             median=sapply(myData, median, na.rm=TRUE),
>             length=sapply(myData, length),
>             unique=sapply(myData, function (x)
>               length(unique(x), replace = TRUE))
>             miss.val=sapply(myData, function(y)
>               sum(length(which(is.na(y))))))
>
> Jeff Reichman
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
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> and provide commented, minimal, self-contained, reproducible code.

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