Since you don&#39;t specify what you really want, all I just can say is take a look at

    ?message # prints a message but not stop execution
    ?warning # prints a warning message but not stop execution
    ?stop # stops execution of the current expression and executes an error action.



Simply include `stop()` inside your function/script

If you&#39;d like an error message, include it inside `stop()` like so

```R
stop(&quot;This is an error message&quot;)
```

I&#39;m having a problem with some program, I have searched about segmentation faults, by I don&#39;t understand them quite well, the only thing I know is that presumably I am trying to access some memory I shouldn&#39;t. The problem is that I see my code and don&#39;t understand what I am doing wrong. 

    #include&lt;stdio.h&gt;
    #include&lt;math.h&gt;
    #include&lt;stdlib.h&gt;

    #define   lambda   2.0
    #define   g        1.0
    #define   Lx       100
    #define   F0       1.0
    #define   Tf       10
    #define   h       0.1
    #define   e       0.00001

    FILE   *file;

    double F[1000][1000000];

    void Inicio(double D[1000][1000000]) {
    int i;
    for (i=399; i&lt;600; i++) {
        D[i][0]=F0;
    }
    }

    void Iteration (double A[1000][1000000]) {
    long int i,k;
    for (i=1; i&lt;1000000; i++) {
        A[0][i]= A[0][i-1] + e/(h*h*h*h)*g*g*(A[2][i-1] - 4.0*A[1][i-1] + 6.0*A[0][i-1]-4.0*A[998][i-1] + A[997][i-1]) + 2.0*g*e/(h*h)*(A[1][i-1] - 2*A[0][i-1] + A[998][i-1]) + e*A[0][i-1]*(lambda-A[0][i-1]*A[0][i-1]);
        A[1][i]= A[1][i-1] + e/(h*h*h*h)*g*g*(A[3][i-1] - 4.0*A[2][i-1] + 6.0*A[1][i-1]-4.0*A[0][i-1] + A[998][i-1]) + 2.0*g*e/(h*h)*(A[2][i-1] - 2*A[1][i-1] + A[0][i-1]) + e*A[1][i-1]*(lambda-A[1][i-1]*A[1][i-1]);
        for (k=2; k&lt;997; k++) {
            A[k][i]= A[k][i-1] + e/(h*h*h*h)*g*g*(A[k+2][i-1] - 4.0*A[k+1][i-1] + 6.0*A[k][i-1]-4.0*A[k-1][i-1] + A[k-2][i-1]) + 2.0*g*e/(h*h)*(A[k+1][i-1] - 2*A[k][i-1] + A[k-1][i-1]) + e*A[k][i-1]*(lambda-A[k][i-1]*A[k][i-1]);
        }
        A[997][i] = A[997][i-1] + e/(h*h*h*h)*g*g*(A[0][i-1] - 4*A[998][i-1] + 6*A[997][i-1] - 4*A[996][i-1] + A[995][i-1]) + 2.0*g*e/(h*h)*(A[998][i-1] - 2*A[997][i-1] + A[996][i-1]) + e*A[997][i-1]*(lambda-A[997][i-1]*A[997][i-1]);
        A[998][i] = A[998][i-1] + e/(h*h*h*h)*g*g*(A[1][i-1] - 4*A[0][i-1] + 6*A[998][i-1] - 4*A[997][i-1] + A[996][i-1]) + 2.0*g*e/(h*h)*(A[0][i-1] - 2*A[998][i-1] + A[997][i-1]) + e*A[998][i-1]*(lambda-A[998][i-1]*A[998][i-1]);
        A[999][i]=A[0][i];
    }
    }

    main() {
    long int i,j;
    Inicio(F);
    Iteration(F);
    file = fopen(&quot;P1.txt&quot;,&quot;wt&quot;);
    for (i=0; i&lt;1000000; i++) {
        for (j=0; j&lt;1000; j++) {
            fprintf(file,&quot;%lf \t %.4f \t %lf\n&quot;, 1.0*j/10.0, 1.0*i, F[j][i]);
        }
    }
    fclose(file);
    }

Thanks for your time. 

segmentation fault : 11

When I do this typecasting:

    (float) &#39;0.00&#39;;

I get `0`. How do I get `0.00` and still have the data type as a float? 

PHP float with 2 decimal places: .00

I was wondering how one is able to produce error messages in R, especially from within a function?

How to return a error message in R?

<p>I was wondering how one is able to produce error messages in R, especially from within a function?</p>


I am using R on Windows 7. Apparently R somehow found evidence that I speak languages besides English, and stubbornly insists on giving output in the console in my own language. For a variety of reasons, this is undesirable, and I want R to be English.

What works
----------

I am able to use `LANGUAGE=en` as a command line option for the R console desktop shortcut, but the language is still wrong in Rstudio, which launches the R executable directly and hence ignores the command line arguments in the shortcut.

What doesn&#39;t work
-----------------

I have tried creating an `.Renviron` file under `C:\Users\[MY_NAME]\Documents`, which is the path returned for the working directory by `getwd()`, with `LANGUAGE=en` in it. R ignores this. My `R_ENVIRON` and `R_ENVIRON_USER` variables show up as `&quot;&quot;` so `.Renviron` should be the correct filename.

I have also tried creating `.Renviron` under `R_HOME\etc` (`R_HOME` points to `C:/PROGRA~1/R/R-215~1.0`) and R also ignores it.

I was somewhat successful with adding `Sys.setenv(LANGUAGE=&quot;en&quot;)` in `R_HOME\etc` - this made all output from the R console English, except for the initial copyright information.

The question
--------

How can I make R default to English such that this is propagated to RStudio?

The R console is in my native language, how can I set R to English?

I&#39;m new to R but I&#39;ve made numerous correlation plots with smaller data sets. However, when I try to plot a large dataset (2gb+), I can produce the plot just fine, but the legend doesn&#39;t show up. Any advice? or alternatives?

    library(gplots)
    r.cor &lt;- cor(r)
    layout(matrix(c(1,1,1,1,1,1,1,1,2,2), 5, 2, byrow = TRUE))
    par(oma=c(5,7,1,1))
    cx &lt;- rev(colorpanel(25,&quot;yellow&quot;,&quot;black&quot;,&quot;blue&quot;))
    leg &lt;- seq(min(r.cor,na.rm=T),max(r.cor,na.rm=T),length=10)
    image(r.cor,main=&quot;Correlation plot Normal/Tumor data&quot;,axes=F,col=cx)
    axis(1, at=seq(0,1,length=ncol(r.cor)), labels=dimnames(r.cor)[[2]], 
        cex.axis=0.9,las=2)
    axis(2,at=seq(0,1,length=ncol(r.cor)), labels=dimnames(r.cor)[[2]],
         cex.axis=0.9,las=2)
    image(as.matrix(leg),col=cx,axes=T)     

&gt; Error in `plot.new()` : figure margins too large

    tmp &lt;- round(leg,2)
    axis(1,at=seq(0,1,length=length(leg)), labels=tmp,cex.axis=1)


Error in plot.new() : figure margins too large in R

This is a bit of a philosophical question about data.table join syntax. I am finding more and more uses for data.tables, but still learning...

The join format `X[Y]` for data.tables is very concise, handy and efficient, but as far as I can tell, it only supports inner joins and right outer joins. To get a left or full outer join, I need to use `merge`:

 - `X[Y, nomatch = NA]` -- all rows in Y -- right outer join  (default)
 - `X[Y, nomatch = 0]` -- only rows with matches in both X and Y -- inner join
 - `merge(X, Y, all = TRUE)` -- all rows from both X and Y -- full outer join
 - `merge(X, Y, all.x = TRUE)` -- all rows in X -- left outer join

It seems to me that it would be handy if the `X[Y]` join format supported all 4 types of joins. Is there a reason only two types of joins are supported?

For me, the `nomatch = 0` and `nomatch = NA` parameter values are not very intuitive for the actions being performed. It is easier for me to understand and remember the `merge` syntax: `all = TRUE`, `all.x = TRUE` and `all.y = TRUE`. Since the `X[Y]` operation resembles `merge` much more than `match`, why not use the `merge` syntax for joins rather than the `match` function&#39;s `nomatch` parameter?

Here are code examples of the 4 join types:

    # sample X and Y data.tables
    library(data.table)
    X &lt;- data.table(t = 1:4, a = (1:4)^2)
    setkey(X, t)
    X
    #    t  a
    # 1: 1  1
    # 2: 2  4
    # 3: 3  9
    # 4: 4 16
    
    Y &lt;- data.table(t = 3:6, b = (3:6)^2)
    setkey(Y, t)
    Y
    #    t  b
    # 1: 3  9
    # 2: 4 16
    # 3: 5 25
    # 4: 6 36

    # all rows from Y - right outer join
    X[Y]  # default
    #  t  a  b
    # 1: 3  9  9
    # 2: 4 16 16
    # 3: 5 NA 25
    # 4: 6 NA 36
    
    X[Y, nomatch = NA]  # same as above
    #    t  a  b
    # 1: 3  9  9
    # 2: 4 16 16
    # 3: 5 NA 25
    # 4: 6 NA 36
    
    merge(X, Y, by = &quot;t&quot;, all.y = TRUE)  # same as above
    #    t  a  b
    # 1: 3  9  9
    # 2: 4 16 16
    # 3: 5 NA 25
    # 4: 6 NA 36
    
    identical(X[Y], merge(X, Y, by = &quot;t&quot;, all.y = TRUE))
    # [1] TRUE
 
    # only rows in both X and Y - inner join
    X[Y, nomatch = 0]  
    #    t  a  b
    # 1: 3  9  9
    # 2: 4 16 16
    
    merge(X, Y, by = &quot;t&quot;)  # same as above
    #    t  a  b
    # 1: 3  9  9
    # 2: 4 16 16
    
    merge(X, Y, by = &quot;t&quot;, all = FALSE)  # same as above
    #    t  a  b
    # 1: 3  9  9
    # 2: 4 16 16
    
    identical( X[Y, nomatch = 0], merge(X, Y, by = &quot;t&quot;, all = FALSE) )
    # [1] TRUE

    # all rows from X - left outer join
    merge(X, Y, by = &quot;t&quot;, all.x = TRUE)
    #    t  a  b
    # 1: 1  1 NA
    # 2: 2  4 NA
    # 3: 3  9  9
    # 4: 4 16 16
 
    # all rows from both X and Y - full outer join
    merge(X, Y, by = &quot;t&quot;, all = TRUE)
    #    t  a  b
    # 1: 1  1 NA
    # 2: 2  4 NA
    # 3: 3  9  9
    # 4: 4 16 16
    # 5: 5 NA 25
    # 6: 6 NA 36

Update: data.table v1.9.6 introduced the `on=` syntax, which allows ad hoc joins on fields other than the primary key. [jangorecki&#39;s answer][1] to the question [How to join (merge) data frames (inner, outer, left, right)?][2] provides some examples of additional join types that data.table can handle.


  [1]: https://stackoverflow.com/a/34219998/1694807
  [2]: https://stackoverflow.com/q/1299871/1694807

Why does X[Y] join of data.tables not allow a full outer join, or a left join?

I&#39;m trying to make a `heatmap` using `ggplot2` using the `geom_tiles` function
here is my code below:

    p&lt;-ggplot(data,aes(Treatment,organisms))+geom_tile(aes(fill=S))+
      scale_fill_gradient(low = &quot;black&quot;,high = &quot;red&quot;) + 
      scale_x_discrete(expand = c(0, 0)) + 
      scale_y_discrete(expand = c(0, 0)) + 
      theme(legend.position = &quot;right&quot;, 
        axis.ticks = element_blank(), 
        axis.text.x = element_text(size = base_size, angle = 90, hjust = 0, colour = &quot;black&quot;),
        axis.text.y = element_text(size = base_size, hjust = 1, colour = &quot;black&quot;)).

data is my data.csv file   
my X axis is types of Treatment  
my Y axis is types of organisms  

I&#39;m not too familiar with commands and programming and I&#39;m relatively new at this. I just want to be able to specify the order of the labels on the x axis. In this case, I&#39;m trying to specify the order of &quot;Treatment&quot;. By default, it orders alphabetically. How do I override this/keep the data in the same order as in my original csv file?

I&#39;ve tried this command

    scale_x_discrete(limits=c(&quot;Y&quot;,&quot;X&quot;,&quot;Z&quot;))

where x, y and z are my treatment condition order. It however doesn&#39;t work very well, and give me missing heat boxes.

How do you specifically order ggplot2 x axis instead of alphabetical order?

By default, it seems that ggplot2 uses a minor grid that is just half of the major grid. Is there any way to to break this up?

For example, I have a plot where the x-axis is years, and the major breaks are (1850, 1900, 1950, 2000). This means the minor grid points are at (1875, 1925, 1975), which is a little unintuitive for years. How can I make the minor grid appear at every decade?

Content Type	Original Author	Original Content on Stackoverflow
Question	petermeissner	View Question on Stackoverflow
Solution 1 - R	Jilber Urbina	View Answer on Stackoverflow
Solution 2 - R	stevec	View Answer on Stackoverflow

How to return a error message in R?

R Problem Overview

R Solutions

Solution 1 - R

Solution 2 - R

PHP float with 2 decimal places: .00

segmentation fault : 11

Attributions