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

[Norman Pat]

Hi David,

> Please find the  attached data sample.

No. Nothing attached. Please read the Rhelp Info page and the Posting Guide.
*I attached it. Anyway I have attached it again (sample train.xlsx).*

Who is assigning you this task? Homework? (Read the Posting Guide.)
*This is my new job role so I have to do that. I know some basic R *

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

That's generally pretty simple if "names" refers to columns in a data frame.
*You mean such as something like names(data.nrow(means==0))*

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

But maybe you mean to process by rows?
*in a column(feature) *

> 3. How to identify features (names) that have outliers such as 99999,-1 in
> the data frame.
*Please refer to the attached excel file*

> 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.
*By looking at data I need to find the outliers*

*Thanks *


On Thu, Mar 31, 2016 at 12:20 PM, David Winsemius <dwinsemius at comcast.net>
wrote:

>
> > 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".
>
> > ______________________________________________
> > R-help at 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.
>
> David Winsemius
> Alameda, CA, USA
>
>