[R] R how to find outliers and zero mean columns?

David Winsemius dwinsemius at comcast.net
Thu Mar 31 03:20:16 CEST 2016


> On Mar 30, 2016, at 3:56 PM, Norman Pat <normanmath1 at gmail.com> wrote:
> 
> Hi team
> 
> I am new to R so please help me to do this task.
> 
> Please find the  attached data sample.

No. Nothing attached. Please read the Rhelp Info page and the Posting Guide.

> But in the original data frame I
> have 350 features and 400000 observations.
> 
> I need to carryout these tasks.

Who is assigning you this task? Homework? (Read the Posting Guide.)

> 1. How to Identify features (names) that have all zeros?

That's generally pretty simple if "names" refers to columns in a dataframe.

> 
> 2. How to remove features that have all zeros from the dataset?

But maybe you mean to process by rows?


> 3. How to identify features (names) that have outliers such as 99999,-1 in
> the data frame.
> 
> 4. How to remove outliers?

You could start by defining "outliers" in something other than vague examples. If this is data from a real-life data gathering effort, then defining outliers would start with an explanation of the context.


> 
> 
> Many thanks

Please at least do the following "homework".

> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.

David Winsemius
Alameda, CA, USA



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