Assuming your dataframe is mydf: 

    mydf$task &lt;- factor(mydf$task, levels = c(&quot;up&quot;, &quot;down&quot;, &quot;left&quot;, &quot;right&quot;, &quot;front&quot;, &quot;back&quot;))

I have tried the following code, but it [doesn&#39;t work][1]. Any idea where I have gone wrong?

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-js --&gt;

    document.getElementsByClassName(&#39;appBanner&#39;).style.visibility=&#39;hidden&#39;;

&lt;!-- language: lang-html --&gt;

    &lt;div class=&quot;appBanner&quot;&gt;appbanner&lt;/div&gt;

&lt;!-- end snippet --&gt;

Using jQuery or changing the HTML is not possible as I am using `[self-&gt;webView stringByEvaluatingJavaScriptFromString:@&quot;&quot;];` in Objective-C.


  [1]: http://jsfiddle.net/rb7bn/207/

Hide element by class in pure Javascript

Please see below my map

    var romanNumeralDict map[int]string = map[int]string{
      1000: &quot;M&quot;,
      900 : &quot;CM&quot;,
      500 : &quot;D&quot;,
      400 : &quot;CD&quot;,
      100 : &quot;C&quot;,
      90  : &quot;XC&quot;,
      50  : &quot;L&quot;,
      40  : &quot;XL&quot;,
      10  : &quot;X&quot;,
      9   : &quot;IX&quot;,
      5   : &quot;V&quot;,
      4   : &quot;IV&quot;,
      1   : &quot;I&quot;,
    }


I am looking to loop through this map in the order of the size of the key

      for k, v := range romanNumeralDict {
        fmt.Println(&quot;k:&quot;, k, &quot;v:&quot;, v)
      }

However, this prints out 

    k: 1000 v: M
    k: 40 v: XL
    k: 5 v: V
    k: 4 v: IV
    k: 900 v: CM
    k: 500 v: D
    k: 400 v: CD
    k: 100 v: C
    k: 90 v: XC
    k: 50 v: L
    k: 10 v: X
    k: 9 v: IX
    k: 1 v: I

Is there a way that I can print them out in the order of the size of the key so, I would like to loop through this map like this

    k:1
    K:4
    K:5
    K:9
    k:10
etc...

Thank you very much for your help!

How to iterate through a map in Golang in order?

I have a data.frame as shown below:

    task    measure
    right   m1
    left    m2
    up      m3
    down    m4
    front   m5
    back    m6
    .
    .
    .

The task column takes only six different values, which are treated as factors, and are ordered by R as: &quot;back&quot;, &quot;down&quot;, &quot;front&quot;, &quot;left&quot;, &quot;right&quot;, &quot;up&quot;.

How ever, I need them ordered as: &quot;up&quot;, &quot;down&quot;, &quot;left&quot;, &quot;right&quot;, &quot;front&quot;, &quot;back&quot;. So that when I use this data in ggplot, the related tasks (such as &quot;up&quot; and &quot;down&quot;) are plotted next to each other.

How can change the ordering of the levels of the factor &quot;task&quot;?

Re-ordering factor levels in data frame

I have a data.frame as shown below:
<pre><code class="hljs language-css">task measure
right m1
left m2
up m3
down m4
front m5
back m6
.
.
.
</code></pre>
The task column takes only six different values, which are treated as factors, and are ordered by R as: "back", "down", "front", "left", "right", "up".
How ever, I need them ordered as: "up", "down", "left", "right", "front", "back". So that when I use this data in ggplot, the related tasks (such as "up" and "down") are plotted next to each other.
How can change the ordering of the levels of the factor "task"?

I want to use the apply function on a dataframe, but only apply the function to the last 5 columns.

    B&lt;- by(wifi,(wifi$Room),FUN=function(y){apply(y, 2, A)})

This applies A to all the columns of y

    B&lt;- by(wifi,(wifi$Room),FUN=function(y){apply(y[4:9], 2, A)})

This applies A only to columns 4-9 of y, but the total return of B strips off the first 3 columns... I still want those, I just don&#39;t want A applied to them.

    wifi[,1:3]+B 

also does not do what I expected/wanted.

R Apply() function on specific dataframe columns

Is there a other version to make the first letter of each string capital and also with FALSE for flac perl?

    name&lt;-&quot;hallo&quot;
    gsub(&quot;(^[[:alpha:]])&quot;, &quot;\\U\\1&quot;, name, perl=TRUE)

First letter to upper case

I have a data frame with 10 columns, collecting actions of &quot;users&quot;, where one of the columns contains an ID (not unique, identifying user)(column 10). the length of the data frame is about 750000 rows. I am trying to extract individual data frames (so getting a list or vector of data frames) split by the column containing the &quot;user&quot; identifier, to isolate the actions of a single actor.

    ID | Data1 | Data2 | ... | UserID
    1  | aaa   | bbb   | ... | u_001
    2  | aab   | bb2   | ... | u_001
    3  | aac   | bb3   | ... | u_001
    4  | aad   | bb4   | ... | u_002

resulting into 

    list(
    ID | Data1 | Data2 | ... | UserID
    1  | aaa   | bbb   | ... | u_001
    2  | aab   | bb2   | ... | u_001
    3  | aac   | bb3   | ... | u_001
    ,
    4  | aad   | bb4   | ... | u_002
    ...)

The following works very well for me on a small sample (1000 rows):

    paths = by(smallsampleMat, smallsampleMat[,&quot;userID&quot;], function(x) x)

and then accessing the element I want by paths[1] for instance.

When applying on the original large data frame or even a matrix representation, this chokes my machine ( 4GB RAM, MacOSX 10.6, R 2.15) and never completes (I know that a newer R version exists, but I believe this is not the main problem). 

It seems that split is more performant and after a long time completes, but I do not know ( inferior R knowledge) how to piece the resulting list of vectors into a vector of matrices.

    path = split(smallsampleMat, smallsampleMat[,10]) 

I have considered also using `big.matrix` etc, but without much success that would speed up the process.


Split a large dataframe into a list of data frames based on common value in column

Is there a way for me to subset data based on column names starting with a particular string? I have some columns which are like `ABC_1 ABC_2 ABC_3` and some like `XYZ_1, XYZ_2,XYZ_3` let&#39;s say.

How can I subset my `df` based only on columns containing the above portions of text (lets say, `ABC` or `XYZ`)? I can use indices, but the columns are too scattered in data and it becomes too much of hard coding.

Also, I want to only include rows from each of these columns where any of their value is `&gt;0` so if either of the `6` columns above has a `1` in the row, it makes a cut into my final data frame.

Subset data to contain only columns whose names match a condition

I am trying to generate all possible combinations of 0 and 1&#39;s in a vector of length 14. Is there an easy way of getting that output as a list of vectors, or even better, a dataframe?

To demonstrate better what I am looking for, let&#39;s suppose that I only want a vector of length 3. I would like to be able to generate the following:

     (1,1,1), (0,0,0), (1,1,0), (1,0,0), (1,0,1), (0,1,0), (0,1,1), (0,0,0)


Generate list of all possible combinations of elements of vector

How can I print a pandas dataframe as a nice text-based table, like the following?

    +------------+---------+-------------+
    | column_one | col_two |   column_3  |
    +------------+---------+-------------+
    |          0 |  0.0001 | ABCD        |
    |          1 |  1e-005 | ABCD        |
    |          2 |  1e-006 | long string |
    |          3 |  1e-007 | ABCD        |
    +------------+---------+-------------+


Pretty Printing a pandas dataframe

I have a dataframe with two columns and intend to convert it to a dictionary. The first column will be the key and the second will be the value.

Dataframe:

        id    value
    0    0     10.2
    1    1      5.7
    2    2      7.4

How can I do this?

How to convert a dataframe to a dictionary

I have 2 dataframes:

restaurant_ids_dataframe 

    Data columns (total 13 columns):
    business_id      4503  non-null values
    categories       4503  non-null values
    city             4503  non-null values
    full_address     4503  non-null values
    latitude         4503  non-null values
    longitude        4503  non-null values
    name             4503  non-null values
    neighborhoods    4503  non-null values
    open             4503  non-null values
    review_count     4503  non-null values
    stars            4503  non-null values
    state            4503  non-null values
    type             4503  non-null values
    dtypes: bool(1), float64(3), int64(1), object(8)`

and 

restaurant_review_frame

    Int64Index: 158430 entries, 0 to 229905
    Data columns (total 8 columns):
    business_id    158430  non-null values
    date           158430  non-null values
    review_id      158430  non-null values
    stars          158430  non-null values
    text           158430  non-null values
    type           158430  non-null values
    user_id        158430  non-null values
    votes          158430  non-null values
    dtypes: int64(1), object(7)


I would like to join these two DataFrames to make them into a single dataframe using the DataFrame.join() command in pandas.

I have tried the following line of code:

    #the following line of code creates a left join of restaurant_ids_frame and   restaurant_review_frame on the column &#39;business_id&#39;
    restaurant_review_frame.join(other=restaurant_ids_dataframe,on=&#39;business_id&#39;,how=&#39;left&#39;)

But when I try this I get the following error:

    Exception: columns overlap: Index([business_id, stars, type], dtype=object)

I am very new to pandas and have no clue what I am doing wrong as far as executing the join statement is concerned.

any help would be much appreciated.
    

Combine two pandas Data Frames (join on a common column)

I&#39;m fairly new to R and I made a type-o while entering some code and now instead of getting the &quot;&gt;&quot; prompt I get a &quot;+&quot; prompt. I appear to be stuck in some kind of function that is looking for input, but I can&#39;t seem to get out of it. I figure that there must be a better way to fix this problem then closing R and rerunning my script but I haven&#39;t been able to find anything on google (likely because I don&#39;t know the right search terms). 
 
Thanks for your help, sorry it&#39;s a trivial question

The code I entered was as follows: 

    &gt; fit = lm(x~`y)
    + fit = lm(x~y)
    + fit
    + summary(fit)
    + 
    + 
    + end
    + ;
    + break
    + )
    + 
    + 
    + 
    +           
    +      
    + quit()
    + 
    + quit
    + break()
    + abline(b0hat,b1hat)
    + return(null)
    + 



ending &quot;+&quot; prompt in R

I want to look at the source code for a function to see how it works. I know I can print a function by typing its name at the prompt:

    &gt; t
    function (x) 
    UseMethod(&quot;t&quot;)
    &lt;bytecode: 0x2332948&gt;
    &lt;environment: namespace:base&gt;

In this case, what does `UseMethod(&quot;t&quot;)` mean?  How do I find the source code that&#39;s actually being used by, for example: `t(1:10)`?

Is there a difference between when I see `UseMethod` and when I see `standardGeneric` and `showMethods`, as with `with`?

    &gt; with
    standardGeneric for &quot;with&quot; defined from package &quot;base&quot;
    
    function (data, expr, ...) 
    standardGeneric(&quot;with&quot;)
    &lt;bytecode: 0x102fb3fc0&gt;
    &lt;environment: 0x102fab988&gt;
    Methods may be defined for arguments: data
    Use  showMethods(&quot;with&quot;)  for currently available ones.

In other cases, I can see that R functions are being called, but I can&#39;t find the source code for those functions.

    &gt; ts.union
    function (..., dframe = FALSE) 
    .cbind.ts(list(...), .makeNamesTs(...), dframe = dframe, union = TRUE)
    &lt;bytecode: 0x36fbf88&gt;
    &lt;environment: namespace:stats&gt;
    &gt; .cbindts
    Error: object &#39;.cbindts&#39; not found
    &gt; .makeNamesTs
    Error: object &#39;.makeNamesTs&#39; not found

How do I find functions like `.cbindts` and `.makeNamesTs`?

In still other cases, there&#39;s a bit of R code, but most of work seems to be done somewhere else.

    &gt; matrix
    function (data = NA, nrow = 1, ncol = 1, byrow = FALSE, dimnames = NULL) 
    {
        if (is.object(data) || !is.atomic(data)) 
            data &lt;- as.vector(data)
        .Internal(matrix(data, nrow, ncol, byrow, dimnames, missing(nrow), 
            missing(ncol)))
    }
    &lt;bytecode: 0x134bd10&gt;
    &lt;environment: namespace:base&gt;
    &gt; .Internal
    function (call)  .Primitive(&quot;.Internal&quot;)
    &gt; .Primitive
    function (name)  .Primitive(&quot;.Primitive&quot;)

How do I find out what the `.Primitive` function does?  Similarly, some functions call `.C`, `.Call`, `.Fortran`, `.External`, or `.Internal`.  How can I find the source code for those?

How can I view the source code for a function?

What is the most effective (ie efficient / appropriate) way to clean up a factor containing multiple levels that need to be collapsed? That is, how to combine two or more factor levels into one.

Here&#39;s an example where the two levels &quot;Yes&quot; and &quot;Y&quot; should be collapsed to &quot;Yes&quot;, and &quot;No&quot; and &quot;N&quot; collapsed to &quot;No&quot;: 
  
    ## Given: 
    x &lt;- c(&quot;Y&quot;, &quot;Y&quot;, &quot;Yes&quot;, &quot;N&quot;, &quot;No&quot;, &quot;H&quot;)   # The &#39;H&#39; should be treated as NA

    ## expectedOutput
    [1] Yes  Yes  Yes  No   No   &lt;NA&gt;
    Levels: Yes No  # &lt;~~ NOTICE ONLY **TWO** LEVELS

----

One option is of course to clean the strings before hand using `sub` and friends. 

Another method, is to allow duplicate label, then drop them

    ## Duplicate levels ==&gt; &quot;Warning: deprecated&quot;
    x.f &lt;- factor(x, levels=c(&quot;Y&quot;, &quot;Yes&quot;, &quot;No&quot;, &quot;N&quot;), labels=c(&quot;Yes&quot;, &quot;Yes&quot;, &quot;No&quot;, &quot;No&quot;))

    ## the above line can be wrapped in either of the next two lines
    factor(x.f)      
    droplevels(x.f) 

However, **is there a more effective way**? 
 
---

While I know that the `levels` and `labels` arguments should be vectors, I experimented with lists and named lists and named vectors to see what happens
Needless to say, none of the following got me any closer to my goal. 

      factor(x, levels=list(c(&quot;Yes&quot;, &quot;Y&quot;), c(&quot;No&quot;, &quot;N&quot;)), labels=c(&quot;Yes&quot;, &quot;No&quot;))
      factor(x, levels=c(&quot;Yes&quot;, &quot;No&quot;), labels=list(c(&quot;Yes&quot;, &quot;Y&quot;), c(&quot;No&quot;, &quot;N&quot;)))

      factor(x, levels=c(&quot;Y&quot;, &quot;Yes&quot;, &quot;No&quot;, &quot;N&quot;), labels=c(Y=&quot;Yes&quot;, Yes=&quot;Yes&quot;, No=&quot;No&quot;, N=&quot;No&quot;))
      factor(x, levels=c(&quot;Y&quot;, &quot;Yes&quot;, &quot;No&quot;, &quot;N&quot;), labels=c(Yes=&quot;Y&quot;, Yes=&quot;Yes&quot;, No=&quot;No&quot;, No=&quot;N&quot;))
      factor(x, levels=c(&quot;Yes&quot;, &quot;No&quot;), labels=c(Y=&quot;Yes&quot;, Yes=&quot;Yes&quot;, No=&quot;No&quot;, N=&quot;No&quot;))


Cleaning up factor levels (collapsing multiple levels/labels)

I am writing codes to export database from R into Excel, I have been trying others codes including:

    write.table(ALBERTA1, &quot;D:/ALBERTA1.txt&quot;, sep=&quot;\t&quot;)
    write.csv(ALBERTA1,&quot;:\ALBERTA1.csv&quot;)
    your_filename_in_R = read.csv(&quot;ALBERTA1.csv&quot;)
    your_filename_in_R = read.csv(&quot;ALBERTA1.csv&quot;)
    write.csv(df, file = &quot;ALBERTA1.csv&quot;)
    your_filename_in_R = read.csv(&quot;ALBERTA1.csv&quot;)
    write.csv(ALBERTA1, &quot;ALBERTA1.csv&quot;)
    write.table(ALBERTA1, &#39;clipboard&#39;, sep=&#39;\t&#39;)
    write.table(ALBERTA1,&quot;ALBERTA1.txt&quot;)
    write.table(as.matrix(ALBERTA2),&quot;ALBERTA2.txt&quot;)
    write.table(as.matrix(vecm.pred$fcst$Alberta_Females[,1]), &quot;vecm.pred$fcst$Alberta_Females[,1].txt&quot;)
    write.table(as.matrix(foo),&quot;foo.txt&quot;)
    write.xlsx(ALBERTA2, &quot;/ALBERTA2.xlsx&quot;)
    write.table(ALBERTA1, &quot;D:/ALBERTA1.txt&quot;, sep=&quot;\t&quot;).
    
Other users of this forum advised me this:
    
    
    write.csv2(ALBERTA1, &quot;ALBERTA1.csv&quot;)
    write.table(kt, &quot;D:/kt.txt&quot;, sep=&quot;\t&quot;, row.names=FALSE)

![enter image description here][1]

You can see on the pictures the outcome I have got from this codes above. But this numbers can&#39;t be used to make any further operations such as addition with other matrices. 

Has someone experienced this kind of problems?

  [1]: http://i.stack.imgur.com/69zFS.jpg

Export data from R to Excel

Someone should have asked this already, but I couldn&#39;t find an answer. Say I have:
  
    x = data.frame(q=1,w=2,e=3, ...and many many columns...)  

what is the most elegant way to rename an arbitrary subset of columns, whose position I don&#39;t necessarily know, into some other arbitrary names?

e.g. Say I want to rename `&quot;q&quot;` and `&quot;e&quot;` into `&quot;A&quot;` and `&quot;B&quot;`, what is the most elegant code to do this?

Obviously, I can do a loop:

    oldnames = c(&quot;q&quot;,&quot;e&quot;)
    newnames = c(&quot;A&quot;,&quot;B&quot;)
    for(i in 1:2) names(x)[names(x) == oldnames[i]] = newnames[i]

But I wonder if there is a better way? Maybe using some of the packages? (`plyr::rename` etc.)


Content Type	Original Author	Original Content on Stackoverflow
Question	siva82kb	View Question on Stackoverflow
Solution 1 - R	Metrics	View Answer on Stackoverflow

Re-ordering factor levels in data frame

R Problem Overview

R Solutions

Solution 1 - R

How to iterate through a map in Golang in order?

Hide element by class in pure Javascript

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