The expression `df1$id %in% idNums1` produces a logical vector.  To negate it, you need to negate the whole vector:

    !(df1$id %in% idNums1)

Can somebody please tell, what&#39;s the difference between the following two statements:

    TimeZone.getTimeZone(&quot;America/New_York&quot;)

and

    TimeZone.getTimeZone(&quot;EST&quot;)

In other words, why is EST different from America/New_York. Also in my application, to get the current time zone in US, should I use America/New_York or EST.



Difference between EST and America/New_York time zones

I want to add an object to the Global scope, and in order to construct it I need to pass it a path to a file.
I don&#39;t want to hard code the file path in the source, and so I want to get that path from the application.conf.

The problem is that I don&#39;t know how to access these properties from the java class.
I tried this:

    Configuration.root().getString(&quot;file.path&quot;)

But it ends with a *NullPointerException*.

Am I wrong in assuming that there&#39;s a global Configuration instance that I can use?
Thanks.

Accessing the application.conf properties from java class with Play! 2.0

&gt; **Possible Duplicate:**  
&gt; [Standard way to remove multiple elements from a dataframe](https://stackoverflow.com/questions/7494848/standard-way-to-remove-multiple-elements-from-a-dataframe)  

&lt;!-- End of automatically inserted text --&gt;

I know in R that if you are searching for a subset of another group or matching based on id you&#39;d use something like

    subset(df1, df1$id %in% idNums1)

My question is how to do the opposite or choose items NOT matching a vector of ids.

I tried using `!` but get the error message

    subset(df1, df1$id !%in% idNums1)

I think my backup is to do sometime like this:

    matches &lt;- subset(df1, df1$id %in% idNums1)
    nonMatches &lt;- df1[(-matches[,1]),]

but I&#39;m hoping there&#39;s something a bit more efficient.


R Not in subset

> Possible Duplicate: 
> <a href="https://stackoverflow.com/questions/7494848/standard-way-to-remove-multiple-elements-from-a-dataframe" target="_blank" rel="noopener noreferrer">Standard way to remove multiple elements from a dataframe</a>

I know in R that if you are searching for a subset of another group or matching based on id you'd use something like
<pre><code class="hljs language-scss">subset(df1, df1$id %in% idNums1)
</code></pre>
My question is how to do the opposite or choose items NOT matching a vector of ids.
I tried using <code>!</code> but get the error message
<pre><code class="hljs language-scss">subset(df1, df1$id !%in% idNums1)
</code></pre>
I think my backup is to do sometime like this:
<pre><code class="hljs language-scss">matches &#x3C;- subset(df1, df1$id %in% idNums1)
nonMatches &#x3C;- df1[(-matches[,1]),]
</code></pre>
but I'm hoping there's something a bit more efficient.

When I need to filter a data.frame, i.e., extract rows that meet certain conditions, I prefer to use the `subset` function:

    subset(airquality, Month == 8 &amp; Temp &gt; 90)

Rather than the `[` function:

    airquality[airquality$Month == 8 &amp; airquality$Temp &gt; 90, ]

There are two main reasons for my preference:

 1. I find the code reads better, from left to right. Even people who know nothing about R could tell what the `subset` statement above is doing.

 2. Because columns can be referred to as variables in the `select` expression, I can save a few keystrokes. In my example above, I only had to type `airquality` once with `subset`, but three times with `[`.

So I was living happy, using `subset` everywhere because it is shorter and reads better, even advocating its beauty to my fellow R coders. But yesterday my world broke apart. While reading the `subset` documentation, I notice this section:

&gt;Warning
&gt;
&gt;This is a convenience function intended for use interactively. For programming it is better to use the standard subsetting functions like [, and in particular the non-standard evaluation of argument subset can have unanticipated consequences.

Could someone help clarify what the authors mean?

First, what do they mean by &quot;*for use interactively*&quot;? I know what an interactive session is, as opposed to a script run in BATCH mode but I don&#39;t see what difference it should make.

Then, could you please explain &quot;*the non-standard evaluation of argument subset*&quot; and why it is dangerous, maybe provide an example?


Why is `[` better than `subset`?

Is it possible to insert a raster image or a pdf image underneath a `geom_line()` on a `ggplot2` plot?

I wanted to be quickly able to plot data over a previously calculated plot that takes a long time to generate as it uses a large amount of data.

I read through this [example][1]. However, as it is over one year old I thought there might be a different way of doing this now.


  [1]: https://kohske.wordpress.com/2010/12/26/use-image-for-background-in-ggplot2/

Inserting an image to ggplot2

I am trying to collect some data from multiple subsets of a data set and need to create a data frame to collect the results.  My problem is don&#39;t know how to create an empty data frame with defined number of columns without actually having data to put into it.

    collect1 &lt;- c()  ## i&#39;d like to create empty df w/ 3 columns: `id`, `max1` and `min1`
    
    for(i in 1:10){
    collect1$id &lt;- i
    ss1 &lt;- subset(df1, df1$id == i)
    collect1$max1 &lt;- max(ss1$value)
    collect1$min1 &lt;- min(ss1$value)
    }

I feel very dumb asking this question (I almost feel like I&#39;ve asked it on SO before but can&#39;t find it) but would greatly appreciate any help.

R define dimensions of empty data frame

I&#39;ve got a bunch of `csv` files that I&#39;m reading into R and including in a package/data folder in  `.rdata` format. Unfortunately the non-ASCII characters in the data fail the check. The `tools` package has two functions to check for non-ASCII characters (`showNonASCII` and `showNonASCIIfile`) but I can&#39;t seem to locate one to remove/clean them.

Before I explore other UNIX tools, it would be great to do this all in R so I can maintain a complete workflow from raw data to final product. Are there any existing packages/functions to help me get rid of the non-ASCII characters?

Removing non-ASCII characters from data files

I have a dataframe with &gt;100 columns, and I would to find the unique rows by comparing only two of the columns. I&#39;m hoping this is an easy one, but I can&#39;t get it to work with `unique` or `duplicated` myself.

In the below, I would like to unique only using `id` and `id2`:

    data.frame(id=c(1,1,3),id2=c(1,1,4),somevalue=c(&quot;x&quot;,&quot;y&quot;,&quot;z&quot;))
  
    id id2 somevalue
    1   1         x
    1   1         y
    3   4         z

I would like to obtain either:

    id id2 somevalue
    1   1         x
    3   4         z

or:

    id id2 somevalue
    1   1         y
    3   4         z

(I have no preference which of the unique rows is kept)

Unique on a dataframe with only selected columns

I have a list of parameters like this:

    public class parameter
    {
        public string name {get; set;}
        public string paramtype {get; set;}
        public string source {get; set;}
    }

    IEnumerable&lt;Parameter&gt; parameters;

And a array of strings i want to check it against.

    string[] myStrings = new string[] { &quot;one&quot;, &quot;two&quot;};

I want to iterate over the parameter list and check if the source property is equal to any of the myStrings array. I can do this with nested foreach&#39;s but i would like to learn how to do it in a nicer way as i have been playing around with linq and like the extension methods on enumerable like where etc so nested foreachs just feel wrong. Is there a more elegant preferred linq/lambda/delegete way to do this. 

Thanks


Check if list&lt;t&gt; contains any of another list

I have data similar to this:

    dt &lt;- structure(list(fct = structure(c(1L, 2L, 3L, 4L, 3L, 4L, 1L, 2L, 3L, 1L, 2L, 3L, 2L, 3L, 4L), .Label = c(&quot;a&quot;, &quot;b&quot;, &quot;c&quot;, &quot;d&quot;), class = &quot;factor&quot;), X = c(2L, 4L, 3L, 2L, 5L, 4L, 7L, 2L, 9L, 1L, 4L, 2L, 5L, 4L, 2L)), .Names = c(&quot;fct&quot;, &quot;X&quot;), class = &quot;data.frame&quot;, row.names = c(NA, -15L))


I want to select rows from this data frame based on the values in the `fct` variable. For example, if I wish to select rows containing either &quot;a&quot; or &quot;c&quot; I can do this:

    dt[dt$fct == &#39;a&#39; | dt$fct == &#39;c&#39;, ]

which yields 

    1    a 2
    3    c 3
    5    c 5
    7    a 7
    9    c 9
    10   a 1
    12   c 2
    14   c 4
as expected. But my actual data is more complex and I actually want to select rows based on the values in a vector such as

    vc &lt;- c(&#39;a&#39;, &#39;c&#39;)

So I tried

    dt[dt$fct == vc, ]

but of course that doesn&#39;t work. I know I could code something to loop through the vector and pull out the rows needed and append them to a new dataframe, but I was hoping there was a more elegant way.


So how can I filter/subset my data based on the contents of the vector `vc`?

Select rows from a data frame based on values in a vector

I have a list in R some 10,000 elements long. Say I want to select only elements, 5, 7, and 9. I&#39;m not sure how I would do that without a for loop.


I want to do something like `mylist[[c(5,7,9]]` but that doesn&#39;t work. I&#39;ve also tried the `lapply` function but haven&#39;t been able to get that working either.


Select multiple elements from a list

I&#39;m familiar with being able to extract columns from an R data frame (or matrix) like so:

    df.2 &lt;- df[, c(&quot;name1&quot;, &quot;name2&quot;, &quot;name3&quot;)]

But can one use a `!` or other tool to select *all but those listed columns*?

For background, I have a data frame with quite a few column vectors and I&#39;d like to avoid:

- Typing out the majority of the names when I could just remove a minority
- Using the much shorter `df.2 &lt;- df[, c(1,3,5)]` because when my .csv file changes, my code goes to heck since the numbering isn&#39;t the same anymore. I&#39;m new to R and think I&#39;ve learned the hard way not to use number vectors for larger df&#39;s that might change.

I tried:

    df.2 &lt;- df[, !c(&quot;name1&quot;, &quot;name2&quot;, &quot;name3&quot;)]
    df.2 &lt;- df[, !=c(&quot;name1&quot;, &quot;name2&quot;, &quot;name3&quot;)]

And just as I was typing this, found out that this works:

    df.2 &lt;- df[, !names(df) %in% c(&quot;name1&quot;, &quot;name2&quot;, &quot;name3&quot;)]

Is there a better way than this last one?

Content Type	Original Author	Original Content on Stackoverflow
Question	screechOwl	View Question on Stackoverflow
Solution 1 - R	Ari B. Friedman	View Answer on Stackoverflow

R Not in subset

R Problem Overview

R Solutions

Solution 1 - R

Accessing the application.conf properties from java class with Play! 2.0

Difference between EST and America/New_York time zones

Attributions