Dont use `write.csv`, use `write.table`

     write.table( &lt;yourdf&gt;, sep=&quot;,&quot;,  col.names=FALSE)

You cannot change many settings in `write.csv` -- the arguments are just there as a reminder to the user.   From the documentation: 

&gt; These wrappers are deliberately inflexible: they are designed to ensure that the correct conventions are used to write a valid file. Attempts to change append, col.names, sep, dec or qmethod are ignored

For the UISearchBars in our app, there&#39;s no cursor shown in the bar with focus when running under iOS 7.  How do we make that show?

We are using the SDK 7, with a minimum target of 6.  We do have the translucency off for the navigation bars, and set the color at runtime.  I can&#39;t think of anything else we are doing differently.

Cursor not displaying in UISearchBar for our app

In my tableView I set a separator line between cells. I am allowing selection of multiple cells. Here&#39;s my code for setting selected cell background color:

    UIView *cellBackgroundColorView = [[UIView alloc] initWithFrame:cell.frame];
    [cellBackgroundColorView setBackgroundColor:[UIColor darkGray]];
    [cell setSelectedBackgroundView:cellBackgroundColorView];

The problem is that if two adjacent cells are selected, there is no separator line between them in iOS7, while there is (as expected) in iOS6.

I even tried setting `cellBackgroundColorView`&#39;s frame height to that of `cell.frame - 1.0`, but that doesn&#39;t work either.

Any ideas?

UITableView separator line disappears when selecting cells in iOS7

I would like to store the contents of my data frame into a .csv file without the names of columns.
I use the following piece of code,
     
    write.csv(cur_data,new_file, row.names = F, col.names=F)

The resulting file looks like this,

    &quot;V1&quot;,&quot;V2&quot;
    -0.02868862,5.442283e-11
    -0.03359281,7.669754e-12
    -0.03801883,-1.497323e-10
    -0.04320051,-6.557672e-11
    

However I would like to have the file in the following format,
    
    -0.02868862,5.442283e-11
    -0.03359281,7.669754e-12
    -0.03801883,-1.497323e-10
    -0.04320051,-6.557672e-11

I don&#39;t understand why the the col.names parameter in the code is not taken into consideration


Write a data frame to csv file without column header in R

I would like to store the contents of my data frame into a .csv file without the names of columns.
I use the following piece of code,
<pre><code class="hljs language-ini">write.csv(cur_data,new_file, row.names = F, col.names=F)
</code></pre>
The resulting file looks like this,
<pre><code class="hljs language-diff">"V1","V2"
-0.02868862,5.442283e-11
-0.03359281,7.669754e-12
-0.03801883,-1.497323e-10
-0.04320051,-6.557672e-11
</code></pre>
However I would like to have the file in the following format,
<pre><code class="hljs language-diff">-0.02868862,5.442283e-11
-0.03359281,7.669754e-12
-0.03801883,-1.497323e-10
-0.04320051,-6.557672e-11
</code></pre>
I don't understand why the the col.names parameter in the code is not taken into consideration

## Background
Several SQL languages (I mostly use postgreSQL) have a function called coalesce which returns the first non null column element for each row. This can be very efficient to use when tables have a lot of `NULL` elements in them. 

I encounter this in a lot of scenarios in R as well when dealing with not so structured data which has a lot of NA&#39;s in them. 

I have made a naive implementation myself but it is ridiculously slow. 

    coalesce &lt;- function(...) {
      apply(cbind(...), 1, function(x) {
              x[which(!is.na(x))[1]]
            })
    }



## Example
    a &lt;- c(1,  2,  NA, 4, NA)
    b &lt;- c(NA, NA, NA, 5, 6)
    c &lt;- c(7,  8,  NA, 9, 10)
    coalesce(a,b,c)
    # [1]  1  2 NA  4  6

## Question
Is there any efficient way to implement `coalesce` in R?


How to implement coalesce efficiently in R

I need to convert a multi-row two-column `data.frame` to a named character vector. 
My `data.frame` would be something like:

    dd = data.frame(crit = c(&quot;a&quot;,&quot;b&quot;,&quot;c&quot;,&quot;d&quot;), 
                    name = c(&quot;Alpha&quot;, &quot;Beta&quot;, &quot;Caesar&quot;, &quot;Doris&quot;)
                    )

and what I actually need would be:

    whatiwant = c(&quot;a&quot; = &quot;Alpha&quot;,
                  &quot;b&quot; = &quot;Beta&quot;,
                  &quot;c&quot; = &quot;Caesar&quot;,
                  &quot;d&quot; = &quot;Doris&quot;)

Converting two columns of a data frame to a named vector

This came up just in an answer to another question here.  When you `rbind` two data frames, it matches columns by name rather than index, which can lead to unexpected behavior:

    &gt; df&lt;-data.frame(x=1:2,y=3:4)
    &gt; df
      x y
    1 1 3
    2 2 4
    &gt; rbind(df,df[,2:1])
      x y
    1 1 3
    2 2 4
    3 1 3
    4 2 4

Of course, there are workarounds.  For example:

    rbind(df,rename(df[,2:1],names(df)))
    data.frame(rbind(as.matrix(df),as.matrix(df[,2:1])))

On edit: `rename` from the `plyr` package doesn&#39;t actually work this way (although I thought I had it working when I originally wrote this...).  The way to do this by renaming is to use SimonO101&#39;s solution:

    rbind(df,setNames(df[,2:1],names(df)))
 

Also, maybe surprisingly, 

    data.frame(rbindlist(list(df,df[,2:1])))

works by index (and if we don&#39;t mind a data table, then it&#39;s pretty concise), so this is a difference between `do.call(rbind)`.

The question is, what is the most concise way to `rbind` two data frames where the names don&#39;t match?  I know this seems trivial, but this kind of thing can end up cluttering code.  And I don&#39;t want to have to write a new function called `rbindByIndex`.  Ideally it would be something like `rbind(df,df[,2:1],byIndex=T)`.

Simplest way to get rbind to ignore column names

There are a lot of posts about replacing NA values. I am aware that one could replace NAs in the following table/frame with the following:

    x[is.na(x)]&lt;-0

But, what if I want to restrict it to only certain columns? Let&#39;s me show you an example.

First, let&#39;s start with a dataset.

    set.seed(1234)
    x &lt;- data.frame(a=sample(c(1,2,NA), 10, replace=T),
                    b=sample(c(1,2,NA), 10, replace=T), 
                    c=sample(c(1:5,NA), 10, replace=T))

Which gives:

        a  b  c
    1   1 NA  2
    2   2  2  2
    3   2  1  1
    4   2 NA  1
    5  NA  1  2
    6   2 NA  5
    7   1  1  4
    8   1  1 NA
    9   2  1  5
    10  2  1  1

Ok, so I only want to restrict the replacement to columns &#39;a&#39; and &#39;b&#39;. My attempt was:

    x[is.na(x), 1:2]&lt;-0

and:

    x[is.na(x[1:2])]&lt;-0

Which does not work.

My data.table attempt, where `y&lt;-data.table(x)`, was obviously never going to work:

    y[is.na(y[,list(a,b)]), ]

I want to pass columns inside the is.na argument but that obviously wouldn&#39;t work.

I would like to do this in a data.frame and a data.table. My end goal is to recode the 1:2 to 0:1 in &#39;a&#39; and &#39;b&#39; while keeping &#39;c&#39; the way it is, since it is not a logical variable. I have a bunch of columns so I don&#39;t want to do it one by one. And, I&#39;d just like to know how to do this.

Do you have any suggestions?

How to replace NA values in a table for selected columns

I have always worked with the `zoo` package, that I have installed a long time ago. Today, I created a new R script, and ran `library(zoo)` and got the following error:

     &gt; library(zoo)
     Error in library(zoo) : there is no package called ‘zoo’

Odd.. Still, I tried reinstalling the package using `install.packages(&quot;zoo&quot;)`, and get the following:

     &gt; install.packages(&quot;zoo&quot;)
     Installing package(s) into ‘C:/Users/U122337.BOSTONADVISORS/Documents/R/win-library/2.15’
     (as ‘lib’ is unspecified)
     --- Please select a CRAN mirror for use in this session ---
     trying URL &#39;http://cran.cnr.Berkeley.edu/bin/windows/contrib/2.15/zoo_1.7-10.zip&#39;
     Content type &#39;application/zip&#39; length 874474 bytes (853 Kb)
     opened URL
     downloaded 853 Kb
  
     package ‘zoo’ successfully unpacked and MD5 sums checked
     Warning: cannot remove prior installation of package ‘zoo’

    The downloaded binary packages are in
        C:\Users\U122337.BOSTONADVISORS\AppData\Local\Temp\Rtmp404t8Y\downloaded_packages

When I try uploading the package, I get the error again that the `zoo` package doesn&#39;t exist.

I have no idea what&#39;s happening. I exited the GUI and restarted it, same problem. I have always worked with this package, and I have no idea why this is happening now.


R not finding package even after package installation

I have a data frame like this: 

    df
                  VALUE              ABS_CALL DETECTION P-VALUE    
        1007_s_at &quot;957.729231881542&quot; &quot;P&quot;      &quot;0.00486279317241156&quot;
        1053_at   &quot;320.632701283368&quot; &quot;P&quot;      &quot;0.0313356324173416&quot; 
        117_at    &quot;429.842323161046&quot; &quot;P&quot;      &quot;0.0170004527476119&quot; 
        121_at    &quot;2395.7364289242&quot;  &quot;P&quot;      &quot;0.0114473584876183&quot; 
        1255_g_at &quot;116.493632746934&quot; &quot;A&quot;      &quot;0.39799368200131&quot;   
        1294_at   &quot;739.927122116896&quot; &quot;A&quot;      &quot;0.0668649772942343&quot; 

I want to convert the row names into the first column. Currently I use something  like this to make row names as the first column:

      d &lt;- df
      names &lt;- rownames(d)
      rownames(d) &lt;- NULL
      data &lt;- cbind(names,d)

Is there a single line to do this?
   

Content Type	Original Author	Original Content on Stackoverflow
Question	Amm	View Question on Stackoverflow
Solution 1 - R	Ricardo Saporta	View Answer on Stackoverflow

Write a data frame to csv file without column header in R

R Problem Overview

R Solutions

Solution 1 - R

UITableView separator line disappears when selecting cells in iOS7

Cursor not displaying in UISearchBar for our app

Attributions