is there a resource to see R symbols and their meanings? I have tried ?dictionary, but it did not have any results. Since the Help page has words and definitions like
?plot bringing up things like
pch
a vector of plotting characters or symbols: see
(underlined) points.
I thought their might be something similar with symbols in r like
" + ? * ~ %>% | [: "
"plus, question, multiply, ?, ?"
It would help me to verbalize them.
As for the pch in plot(), it is called a parameter. You can find the explanation of the parameters by
?par
As for " + ? * ~ %>% | [: " these are functions. To find their explanations, you can use backticks :
?`+`
?`?`
?`*`
?`~`
?`[`
and so on.
EDIT (to highlight important information in my comment) :
If you want to get a comprehensive explanation of those parameters and symbolic functions, I highly recommend An
Introduction to R by W. N. Venables, D. M. Smith and the R Core Team, available here. Check "Appendix D Function and variable index" to find the page number of any function.
Related
I'm trying to rename a specific column in my R script using the colnames function but with no sucess so far.
I'm kinda new around programming so it may be something simple to solve.
Basically, I'm trying to rename a column called Reviewer Overall Notes and name it Nota Final in a data frame called notas with the codes:
colnames(notas$`Reviewer Overall Notes`) <- `Nota Final`
and it returns to me:
> colnames(notas$`Reviewer Overall Notes`) <- `Nota Final`
Error: object 'Nota Final' not found
I also found in [this post][1] a code that goes:
colnames(notas) [13] <- `Nota Final`
But it also return the same message.
What I'm doing wrong?
Ps:. Sorry for any misspeling, English is not my primary language.
You probably want
colnames(notas)[colnames(notas) == "Reviewer Overall Notes"] <- "Nota Final"
(#Whatif's answer shows how you can do this with the numeric index, but probably better practice to do it this way; working with strings rather than column indices makes your code both easier to read [you can see what you're renaming] and more robust [in case the order of columns changes in the future])
Alternatively,
notas <- notas %>% dplyr::rename(`Nota Final` = `Reviewer Overall Notes`)
Here you do use back-ticks, because tidyverse (of which dplyr is a part) prefers its arguments to be passed as symbols rather than strings.
Why using backtick? Use the normal quotation mark.
colnames(notas)[13] <- 'Nota Final'
This seems to matter:
df <- data.frame(a = 1:4)
colnames(df)[1] <- `b`
Error: object 'b' not found
You should not use single or double quotes in naming:
I have learned that we should not use space in names. If there are spaces in names (it works and is called a non-syntactic name: And according to Wickham Hadley's description in Advanced R book this is due to historical reasons:
"You can also create non-syntactic bindings using single or double quotes (e.g. "_abc" <- 1) instead of backticks, but you shouldn’t, because you’ll have to use a different syntax to retrieve the values. The ability to use strings on the left hand side of the assignment arrow is an historical artefact, used before R supported backticks."
To get an overview what syntactic names are use ?make.names:
make.names("Nota Final")
[1] "Nota.Final"
In Julia, how can I check an English word is a meaningful word? Suppose I want to know whether "Hello" is meaningful or not. In Python, one can use the enchant or nltk packages(Examples: [1],[2]). Is it possible to do this in Julia as well?
What I need is a function like this:
is_english("Hello")
>>>true
is_english("Hlo")
>>>false
# Because it doesn't have meaning! We don't have such a word in English terminology!
is_english("explicit")
>>>true
is_english("eeplicit")
>>>false
Here is what I've tried so far:
I have a dataset that contains frequent 5char English words(link to google drive). So I decided to augment it to my question for better understanding. Although this dataset is not adequate (because it just contains frequent 5char meaningful words, not all the meaningful English words with any length), it's suitable to use it to show what I want:
using CSV
using DataFrames
df = CSV.read("frequent_5_char_words.csv" , DataFrame , skipto=2)
df = [lowercase(item) for item in df[:,"0"]]
function is_english(word::String)::Bool
return lowercase(word) in df
end
Then when I try these:
julia>is_english("Helo")
false
julia>is_english("Hello")
true
But I don't have an affluent dataset! So this isn't enough. So I'm curious if there are any packages like what I mentioned before, in Julia or not?
(not enough rep to post a comment!)
You can still use NLTK in Julia via PyCall. Or, as it seems you don't need an NLP tool but just a dictionary, you can use wiktionary to do some lookup or build the dataset.
There is a recently new package, Named LanguageDetect.jl. It does not return true/false, but a list of probabilities. You could define something like:
using LanguageDetect: detect
function is_english(text, threshold=0.8)
langs = detect(text)
for lang in langs
if lang.language == "en"
return lang.probability >= threshold
end
end
ret
I know there are ways to extract all arguments to a function using, for example, rlang::fn_fmls. But is it possible to extract the description of one of these arguments from the package documentation?
For example, what if I wanted to extract the description of the na.rm argument to base::sum()?
I'm imagining something like:
get_argument_description(fn = 'base::sum', arg = 'na.rm')
Return:
"logical. Should missing values (including NaN) be removed?"
You could try to read the associated help file for that function, and grep the line where \item{argument}. However, multi-line help texts are allowed, if the next line does not start with a \ you would want to grab that too.
This answer shows a way to acess the file, then it is just a matter of grabbing the correct line(s). I also want to highlight a different function in tools,
tools:::.Rd_get_text()
Which almost gets you where you want, (if you find the correct line)
library(tools)
db = Rd_db("base")
tools:::.Rd_get_text(x = db[["sum.Rd"]])[21] # 21 is the line you want here
[1] " na.rm: logical. Should missing values (including 'NaN') be removed?"
This is a follow up question to "Displaying a greater than or equal sign"
This is the text I wish to display as the y axis label:
Pr(Number of Invasions, X ≥ x)
This is the code:
expression(paste("Pr(Number of Invasions, ", italic('X'), "\u2265", italic('x'), ")"))
What I get is:
Pr(Number of Invasions, X = x)
This is the same result in the thread mentioned above. "\u2265" is supposed to overcome the issue, as suggested in the answers to the thread but it doesn't in my case.
When I run "\u2265" the result is:
"\u2265"
[1] "≥"
When I assign this to an object I get the same result:
symbol<-"\u2265"
symbol
[1] "≥"
However, in the Global Environment the object "symbol" contains "=".
Can anyone suggest how to display the symbol in the plot?
The answer isn't obvious to me.
I'm using RStudio, and OS system is Windows 7
By placing quotations marks around >= or \u2265 within paste within expression, it is was not able to produce the right symbol.
Even though I was formatting the Xs in italics, I should have just treated the code as if it was X>=x, which is what expression really wants to see, as MrFlick suggested... which makes sense now.
So:
expression(paste("Pr(Number of Invasions", italic('X')>=italic('x'), ")"))
Thanks MrFick!
You don't need paste. It's often clearer to use ~ and * as separators
plot(1,1, xlab=expression(Pr*'('*Number~of~Invasions~~ italic(X)*'\u2265'*italic(x)*")") )
That way it's easier to transition to the "full" plotmath version which gets a different spacing and looks better:
plot(1,1,
xlab=expression( Pr*'('*Number~of~Invasions~~ italic(X) >= italic(x)*")" )
)
If you had really wanted to have a named token hold the "≥" character, you can use the bquote and .( )-functions. The names inside the .( ) get evaluated (when the dot-function is within bquote):
symbol<-"\u2265"
plot(1,1,xlab=bquote(Pr*'('*Number~of~Invasions~~ italic(X) * .(symbol) * italic(x)*")") )
In r language, what is the meaning of "str" in "ls.str()"? I understand that ls.str() gives you a detailed description of the objects in the active memory. But I am still confused about what str stands for then?
From ?ls.str:
‘ls.str’ and ‘lsf.str’ are variations of ‘ls’ applying ‘str()’
From ?str:
Compactly display the internal *str*ucture of an R object ...
so the answer is "list structures".
Taken from the Full reference manual.
str
Compactly Display the Structure of an Arbitrary R Object
Description
Compactly display the internal
str
ucture of an
R
object, a diagnostic function and an alternative to
summary
(and to some extent,
dput
). Ideally, only one line for each ‘basic’ structure is displayed. It
is especially well suited to compactly display the (abbreviated) contents of (possibly nested) lists.
The idea is to give reasonable output for
any
R
object. It calls
args
for (non-primitive) function
objects.
strOptions()
is a convenience function for setting
options
(str = .)
, see the examples.
The abbreviation "str" is taken from the first 3 letters of the word structure.
[The same is highlighted in the official R documentation below]
https://www.rdocumentation.org/packages/utils/versions/3.5.1/topics/str