Try using a pipe `|` in each line:

    ---
    title: |
      | Veryyyyyyy  
      | yyyyyyyyyyyyyy Looooo  
      | oooooooooooooooo
      | oooooooooooong 
      
    author: &quot;Foo Bar&quot;
    date: &quot;6 March 2015&quot;
    output: html_document
    ---
![enter image description here][1]


  [1]: http://i.stack.imgur.com/gngpM.png

For a centered, multi-line title: 
    
    ---
    title: |
      &lt;center&gt; Veryyyyyyy &lt;/center&gt;
      &lt;center&gt; yyyyyyyyyyyyyy Looooo &lt;/center&gt;
      &lt;center&gt; oooooooooooooooo &lt;/center&gt;
      &lt;center&gt; oooooooooooong &lt;/center&gt;

    author: &quot;Foo Bar&quot;
    date: &quot;6 March 2015&quot;
    output: html_document
    ---

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/4X326.png

I know that this is an old post, but I wanted to chime in with:

```
# A Title of some kind
&lt;br&gt;&lt;br&gt;&lt;br&gt;&lt;br&gt;&lt;br&gt;  
      
# Another title that has 5 blank lines above it
```

Note that you need 2 spaces on line 3 or the title will not display properly in Rmarkdown::html_document. This solution is a little hard to find, hope it helps!


In C and C++ (and several other languages) horizontal tabulators (ASCII code 9) in character and string constants are denoted in escaped form as `&#39;\t&#39;` and `&quot;\t&quot;`. However, I am regularly typing the unescaped tabulator character in string literals as for example in &lt;code&gt;&quot;A&amp;#x0009;B&quot;&lt;/code&gt; (there is a TAB in betreen `A` and `B`), and at least clang++ does not seem to bother - the string seems to be equivalent to `&quot;A\tB&quot;`. I like the unescaped version better since long indented multi-line strings are better readable in the source code.

Now I am asking myself whether this is generally legal in C and C++ or just supported by my compiler. How portable are unescaped tabulators in character and string constants?

Surprisingly I could not find an answer to this seemingly simple question, neither with Google nor on stackoverflow (I just found [this](https://stackoverflow.com/questions/14297477/how-do-you-insert-a-tab-in-a-string) vaguely related question).


Is it mandatory to escape tabulator characters in C and C++?

UPDATE FIXED 1/18/15
---
After we recently updated to MySQL 5.6.27 (from the Ubuntu repo), this option now works. So this appears to have been a problem with the previous version of MySQL.

ORIGINAL QUESTION
---
With a new upgrade to MySQL (5.6.20), updates and inserts fail unless I set sql-mode to NO_ENGINE_SUBSTITUTION.

Thanks to the [documentation](http://dev.mysql.com/doc/refman/5.6/en/sql-mode.html), I can run the following from mysql terminal and that fixes the problem (temporarily):

    SET GLOBAL sql_mode = &#39;NO_ENGINE_SUBSTITUTION&#39;;
    SET SESSION sql_mode = &#39;NO_ENGINE_SUBSTITUTION&#39;;`

But the next time MySQL restarts, these settings are lost. 

So I have tried to make that permanent by editing /etc/mysql/my.cnf (on my standard server running Ubuntu 12.04.5 LTS), and adding the config settings that the [documentation](http://dev.mysql.com/doc/refman/5.6/en/sql-mode.html) says should be added:

    [mysqld]
    sql-mode=&quot;NO_ENGINE_SUBSTITUTION&quot;

Alternative Syntaxes for Testing
---
Just for testing purposes, I have also tried the following formats (which do not cause errors when restarting MySQL, but they do not affect the setting).

    # dash no quotes
    sql-mode=NO_ENGINE_SUBSTITUTION
    # underscore no quotes
    sql_mode=NO_ENGINE_SUBSTITUTION
    # underscore and quotes
    sql_mode=&quot;NO_ENGINE_SUBSTITUTION&quot;

Nothing works. After restart this setting is lost and I have to run the commands manually again from mysql terminal to make saving work again. 


Alternative Locations
---

 - I know /etc/mysql/my.cnf is being referenced because we have replication defined in this file, and that is working.
 - There is not another identical setting in this file that is overwriting it.

I get a list of the config files that are being referenced by running this from the command line:

    mysqld --help --verbose

I see a line that reads:

    Default options are read from the following files in the given order:
    /etc/my.cnf /etc/mysql/my.cnf /usr/etc/my.cnf ~/.my.cnf 

This is the default location it &quot;looks&quot; for files, it doesn&#39;t mean that it actually found a file there, e.g. my server doesn&#39;t have `/etc/my.cnf`, `/usr/etc/my.cnf` or `~/.my.cnf`.

So it looks like my config in /etc/mysql/my.cnf is the only file mysql is referencing, and therefore this setting is not being overwritten. 

Logical Conclusion of Testing
---
Logically then, it seems the syntax is not correct or is being ignored for some other reason. Any other ideas?

How to make sql-mode=&quot;NO_ENGINE_SUBSTITUTION&quot; permanent in MySQL my.cnf

I have a quite long title in a rmarkdown document and I would like to force a line break in a specific position.

Minimum example:

    ---
    title: &quot;Quite long title want the * line break at the asterisk&quot;
    output: html_document
    ---

I have tried: \n, \newline, \\\\ and a manual line break. None of them seem to work.

I believe it has to be quite straightforward but I haven&#39;t been able to find a solution.





How can I force a line break in rmarkdown&#39;s title?

I have a quite long title in a rmarkdown document and I would like to force a line break in a specific position.
Minimum example:
<pre><code class="hljs language-yaml">---
title: "Quite long title want the * line break at the asterisk"
output: html_document
---
</code></pre>
I have tried: \n, \newline, \\ and a manual line break. None of them seem to work.
I believe it has to be quite straightforward but I haven't been able to find a solution.

So we are used to say to every R new user that &quot;*`apply` isn&#39;t vectorized, check out the Patrick Burns [R Inferno](http://www.burns-stat.com/pages/Tutor/R_inferno.pdf) Circle 4*&quot; which says (I quote):

&gt; A common reflex is to use a function in the apply family. **This is not**
&gt; **vectorization, it is loop-hiding**. The apply function has a for loop in
&gt; its definition. The lapply function buries the loop, but execution
&gt; times tend to be roughly equal to an explicit for loop.

Indeed, a quick look on the `apply` source code reveals the loop:

    grep(&quot;for&quot;, capture.output(getAnywhere(&quot;apply&quot;)), value = TRUE)
    ## [1] &quot;        for (i in 1L:d2) {&quot;  &quot;    else for (i in 1L:d2) {&quot;

Ok so far, but a look at `lapply` or `vapply` actually reveals a completely different picture:

    lapply
    ## function (X, FUN, ...) 
    ## {
    ##     FUN &lt;- match.fun(FUN)
    ##     if (!is.vector(X) || is.object(X)) 
    ##        X &lt;- as.list(X)
    ##     .Internal(lapply(X, FUN))
    ## }
    ## &lt;bytecode: 0x000000000284b618&gt;
    ## &lt;environment: namespace:base&gt;

So apparently there is no R `for` loop hiding there, rather they are calling internal C written function. 

A quick look in the [rabbit](https://github.com/wch/r-source/blob/trunk/src/main/names.c#L627-L630) [hole](https://github.com/wch/r-source/blob/trunk/src/main/apply.c#L34) reveals pretty much the same picture

Moreover, let&#39;s take the `colMeans` function for example, which was never accused in not being vectorised

    colMeans
    # function (x, na.rm = FALSE, dims = 1L) 
    # {
    #   if (is.data.frame(x)) 
    #     x &lt;- as.matrix(x)
    #   if (!is.array(x) || length(dn &lt;- dim(x)) &lt; 2L) 
    #     stop(&quot;&#39;x&#39; must be an array of at least two dimensions&quot;)
    #   if (dims &lt; 1L || dims &gt; length(dn) - 1L) 
    #     stop(&quot;invalid &#39;dims&#39;&quot;)
    #   n &lt;- prod(dn[1L:dims])
    #   dn &lt;- dn[-(1L:dims)]
    #   z &lt;- if (is.complex(x)) 
    #     .Internal(colMeans(Re(x), n, prod(dn), na.rm)) + (0+1i) * 
    #     .Internal(colMeans(Im(x), n, prod(dn), na.rm))
    #   else .Internal(colMeans(x, n, prod(dn), na.rm))
    #   if (length(dn) &gt; 1L) {
    #     dim(z) &lt;- dn
    #     dimnames(z) &lt;- dimnames(x)[-(1L:dims)]
    #   }
    #   else names(z) &lt;- dimnames(x)[[dims + 1]]
    #   z
    # }
    # &lt;bytecode: 0x0000000008f89d20&gt;
    #   &lt;environment: namespace:base&gt;

Huh? It also just calls `.Internal(colMeans(...` which we can also find in the [rabbit hole](https://github.com/wch/r-source/blob/trunk/src/main/names.c#L731). So how is this different from `.Internal(lapply(..`?

Actually a quick benchmark reveals that `sapply` performs no worse than `colMeans` and much better than a `for` loop for a big data set

    m &lt;- as.data.frame(matrix(1:1e7, ncol = 1e5))
    system.time(colMeans(m))
    # user  system elapsed 
    # 1.69    0.03    1.73 
    system.time(sapply(m, mean))
    # user  system elapsed 
    # 1.50    0.03    1.60 
    system.time(apply(m, 2, mean))
    # user  system elapsed 
    # 3.84    0.03    3.90 
    system.time(for(i in 1:ncol(m)) mean(m[, i]))
    # user  system elapsed 
    # 13.78    0.01   13.93 

In other words, is it correct to say that `lapply` and `vapply` **are actually vectorised** (compared to `apply` which is a `for` loop that also calls `lapply`) and what did Patrick Burns really mean to say?


Is the &quot;*apply&quot; family really not vectorized?

I know that in Shiny Server Pro there is a function of password control.
The question is that Shiny has function passwordInput(), which is like textInput()
Has anybody thought about how to do the following:

1) Launching the application only after correct password input
2) Launching the part of application after correct password input (for example, I have some tabs in shinydashboard, and I want to make an acces to one of them only by password)

Thanks!

Starting Shiny app after password input

What&#39;s the difference between `doParallel` and `doMC` in R concerning `foreach` function? `doParallel` supports windows, unix-like, while `doMC` supports unix-like only. In other words, why `doParallel` cannot replace `doMC` directly? Thank you.


Update:
`doParallel` is built on `parallel`, which is essentially a merger of `multicore` and `snow` and automatically uses the appropriate tool for your system. As a result, we can use `doParallel` to support multi systems. In other words, we can use `doParallel` to replace `doMC`.

ref: http://michaeljkoontz.weebly.com/uploads/1/9/9/4/19940979/parallel.pdf

BTW, what is the difference between `registerDoParallel(ncores=3)` and 

    cl &lt;- makeCluster(3)
    registerDoParallel(cl)


It seems `registerDoParallel(ncores=3)` can stop cluster automatically, while the second do not stop automatically and needs `stopCluster(cl)`.

ref: http://cran.r-project.org/web/packages/doParallel/vignettes/gettingstartedParallel.pdf



the difference between doMC and doParallel in R

I want to select multiple columns based on their names with a *regex* expression. I am trying to do it with the piping syntax of the `dplyr` package. I checked the other topics, but only found answers about a single string.

With base R:

    library(dplyr)    
    mtcars[grepl(&#39;m|ar&#39;, names(mtcars))]
    ###                      mpg am gear carb
    ### Mazda RX4           21.0  1    4    4
    ### Mazda RX4 Wag       21.0  1    4    4

However it doesn&#39;t work with the select/contains way:

    mtcars %&gt;% select(contains(&#39;m|ar&#39;))
    ### data frame with 0 columns and 32 rows

What&#39;s wrong?


select columns based on multiple strings with dplyr contains()

How would I got about installing multiple packages in R? 

I tried the following code:

    install.packages(&quot;EIAdata&quot;, &quot;gdata&quot;, &quot;ggmap&quot;, &quot;ggplot2&quot;,&quot;gridExtra&quot;,&quot;ISOweek&quot;,&quot;kobe&quot;,&quot;lubridate&quot;,&quot;maps&quot;,&quot;MASS&quot;,&quot;memisc&quot;,&quot;pander&quot;,&quot;plyr&quot;,&quot;psych&quot;,&quot;Quandl&quot;,&quot;quantmod&quot;,&quot;reshape2&quot;,&quot;rgeos&quot;,&quot;Rgnuplot&quot;,&quot;RODBC&quot;,&quot;scales&quot;,&quot;sp&quot;,&quot;sqldf&quot;,&quot;stockPortfolio&quot;,&quot;stringi&quot;,&quot;stringr&quot;,&quot;XLConnect&quot;, &quot;xlsReadWrite&quot;,&quot;zipcode&quot;)

This code works: 

    install.packages(&quot;ggplot2&quot;)

Why won&#39;t the line with the multiple packages work?

How to install multiple packages?

In RMarkdown is there a way to specify the font color? 

There doesn&#39;t seem to be an option while browsing through the [chunk options][1] 




  [1]: http://yihui.name/knitr/options/#chunk_options

RMarkdown: How to change the font color?

I am using R Markdown in RStudio and the knit HTML option to create HTML output. However, the font used in the ouput for plain text blocks is rather small and I would like to change it to a differnt font and increase the font size. Can someone show an example how to set the output font - workable without a lot of knowledge in html?

So far I tried at the top of my markdown document, but this doesn&#39;t work. 

    ---
    fontsize: 24pt
    ---

R Markdown - changing font size and font type in html output

I am using knitr (1.9.5 and 1.9.17) and rmarkdown (0.5.3.1), and would like to hold figure position in the pdf output. The generated pdf file is working fine when chunk option `fig.pos=&quot;H&quot;` is used. 

However, the figure position is not hold when `fig_caption: yes` is set in the 
yaml header.

How should I fix this problem? Thanks for any suggestions.

EDIT:

After learning the float environment of Latex. I add `float` package into header.

    \usepackage{float}

But the generated tex file always use `htbp` in the `figure` environment regard to any `fig.pos` options are used. After manually changing `htbp` to `H`, positions of all figures are hold.

This is my example of rmd file:

    ---
    title: &quot;Untitled&quot;
    output:
      pdf_document:
        fig_caption: yes
        includes:
            in_header: mystyles.sty
    ---
    
    # Section 1
    
    
    Note that the `echo = FALSE` parameter was added to the code chunk to prevent printing of the R code that generated the plot.
    
    Note that the `echo = FALSE` parameter was added to the code chunk to prevent printing of the R code that generated the plot.
    
    Note that the `echo = FALSE` parameter was added to the code chunk to prevent printing of the R code that generated the plot.
    
    Note that the `echo = FALSE` parameter was added to the code chunk to prevent printing of the R code that generated the plot.
    
    
    ```{r fig1, echo=FALSE, fig.height=8.5, fig.pos=&quot;H&quot;}
    plot(cars)
    ```
    
    # Section 2
    
    More test
    
    ```{r fig2, echo=FALSE, fig.height=8.5, fig.pos=&quot;H&quot;}
    plot(cars)
    ```
    
    # Section 3
    
    ```{r fig3, echo=FALSE, fig.height=8.5, fig.pos=&quot;H&quot;}
    plot(cars)
    ```
    
    More test

How to hold figure position with figure caption in pdf output of knitr?

I am putting together an R Markdown HTML page for some new R users at my work to give them an introduction and walk them through some simple demos.

While showing off things like `head` and `tail`, it ends up looking messy and long because it prints out each output one after the other. I would like them as long as other sections of my .Rmd to be split into two columns.

In my research, I came across this [question](https://stackoverflow.com/questions/19237190/2-column-report-in-r-markdown-render-html-aside-data-frame). There was some discussion of workarounds with HTML code I did not understand.

I did try including:
```
&lt;div class=&quot;columns-2&quot;&gt;   
&lt;/div&gt;
```
from the official `rmarkdown` documentation, but it did not have any effect.

As I was ready to give up, there was a comment on the Stack Overflow question by @Molx saying that you can separate columns with `***`, but it did not give any further explanation. I tried it out in a few ways: I included the `***` in the middle of my R code chunk, I separated my R code chunks and put the `***` between the two. When I did the latter, the `***` simply became a horizontal rule and did nothing with columns.

I am hoping to avoid tables and CSS if possible.

How to export RMarkdown file to HTML document with two columns?

I&#39;ve got an Rmarkdown template that works well, and I&#39;ve parameterized it so I can generate variants of the same report from different data sources. However, I&#39;d like to change the title of the report in each case. How do I do that? 

Here&#39;s the YAML header I have so far:

    ---
    title: &quot;My Title&quot;
    author: &quot;Me, Inc.&quot;
    date: &quot;August 4, 2015&quot;
    output: pdf_document
    params:
      title: default
    ---

I&#39;ve tried using `params=list(title=&quot;ASDF&quot;)` in the call to `rmarkdown::render`, and although my code can see that variable, it doesn&#39;t change the title. I&#39;ve also tried using `r params$title` in the YAML, but that gives a syntax error.

Is there something else I should be trying? Thanks!


Content Type	Original Author	Original Content on Stackoverflow
Question	Jon Nagra	View Question on Stackoverflow
Solution 1 - R	Peter Diakumis	View Answer on Stackoverflow
Solution 2 - R	filups21	View Answer on Stackoverflow
Solution 3 - R	Bartimus	View Answer on Stackoverflow

How can I force a line break in rmarkdown's title?

R Problem Overview

R Solutions

Solution 1 - R

Solution 2 - R

Solution 3 - R

How to make sql-mode="NO_ENGINE_SUBSTITUTION" permanent in MySQL my.cnf

Is it mandatory to escape tabulator characters in C and C++?

Attributions