I did a colorful print this way:
* print "\x1B[31;40m\n========================================\n\x1B[0m"
Is there a simpler way to this approach?
Related
In my *.Rmd file I'm writing something like this
$\text{Dia}_i = \max_{x, y \in C_i} d(x,y)$
And I was expecting this
but when doing bookdown::render_book(...) and controlling the results in my browser firefox I got
I found that this has something to do with the namelimits (first picture) and nonamelimits (second picture) but unfortunately I have no clue how to change the outcome.
Question: What kind of code chunk I have to add that I can switch between the two notations?
Thanks a lot in advance!
Edit_1
Can I mix these two types?! The goal is to have an inline formula with the desired apperance.
Edit_2
This is my Code - the three dots (...) are the magic/unknown code
And this is my desired output
But sadly I get this
My wish summerized
This should work, following https://stackoverflow.com/a/61979164/13249862:
Add this to your YAML header:
header-includes:
- \newcommand{\argmax}{\mathop{\mathrm{max}}\limits}
Then, you can write both equations:
This $\text{Dia}_i = \argmax_{x, y \in C_i} d(x,y)$, or this $\text{Dia}_i = \max_{x, y \in C_i} d(x,y)$.
Result:
There seems to be 3 ways to display output in Jupyter:
By using print
By using display
By just writing the variable name
What is the exact difference, especially between number 2 and 3?
I haven't used display, but it looks like it provides a lot of controls. print, of course, is the standard Python function, with its own possible parameters.
But lets look at a simple numpy array in Ipython console session:
Simply giving the name - the default out:
In [164]: arr
Out[164]: array(['a', 'bcd', 'ef'], dtype='<U3')
This is the same as the repr output for this object:
In [165]: repr(arr)
Out[165]: "array(['a', 'bcd', 'ef'], dtype='<U3')"
In [166]: print(repr(arr))
array(['a', 'bcd', 'ef'], dtype='<U3')
Looks like the default display is the same:
In [167]: display(arr)
array(['a', 'bcd', 'ef'], dtype='<U3')
print on the other hand shows, as a default, the str of the object:
In [168]: str(arr)
Out[168]: "['a' 'bcd' 'ef']"
In [169]: print(arr)
['a' 'bcd' 'ef']
So at least for a simple case like this the key difference is between the repr and str of the object. Another difference is which actions produce an Out, and which don't. Out[164] is an array. Out[165] (and 168) are strings. print and display display, but don't put anything on the Out list (in other words they return None).
display can return a 'display' object, but I won't get into that here. You can read the docs as well as I can.
I am writing up some data processing stuff and I wanted to have a concise progress status printing a fraction that updates over time on a single line in the console.
To get this done I wanted to have something like this
print(Initiating data processing...)
for(sample in 1:length(data)){
print(paste(sample,length(data),sep="/"))
process(data[[sample]])
#Unprint the bottom line in the console ... !!! ... !!!.. ?
}
Keeping the screen clean and what not. I don't quite know how to do it. I know that there is a R text progress bar but for utilities sake I'm looking for a little more control.
Thanks!
I think your best bet is to do exactly what the R text progress bar does, which is "\r to return to the left margin", as seen in the help file. You'll have to use cat instead of print because print ends with a newline.
cat("Initiating data processing...\n")
for(sample in 1:length(data)){
cat(sample, length(data), sep="/")
process(data[[sample]])
cat("\r")
}
cat("\n")
I (sort of) already know the answer to this question. But I figured it is one that gets asked so frequently on the R Users list, that there should be one solid good answer. To the best of my knowledge there is no multiline comment functionality in R. So, does anyone have any good workarounds?
While quite a bit of work in R usually involves interactive sessions (which casts doubt on the need for multiline comments), there are times when I've had to send scripts to colleagues and classmates, much of which involves nontrivial blocks of code. And for people coming from other languages it is a fairly natural question.
In the past I've used quotes. Since strings support linebreaks, running an R script with
"
Here's my multiline comment.
"
a <- 10
rocknroll.lm <- lm(blah blah blah)
...
works fine. Does anyone have a better solution?
You can do this easily in RStudio:
select the code and click CTR+SHIFT+C
to comment/uncomment code.
This does come up on the mailing list fairly regularly, see for example this recent thread on r-help. The consensus answer usually is the one shown above: that given that the language has no direct support, you have to either
work with an editor that has region-to-comment commands, and most advanced R editors do
use the if (FALSE) constructs suggested earlier but note that it still requires complete parsing and must hence be syntactically correct
A neat trick for RStudio I've just discovered is to use #' as this creates an self-expanding comment section (when you return to new line from such a line or insert new lines into such a section it is automatically comment).
[Update] Based on comments.
# An empty function for Comments
Comment <- function(`#Comments`) {invisible()}
#### Comments ####
Comment( `
# Put anything in here except back-ticks.
api_idea <- function() {
return TRUE
}
# Just to show api_idea isn't really there...
print( api_idea )
`)
####
#### Code. ####
foo <- function() {
print( "The above did not evaluate!")
}
foo()
[Original Answer]
Here's another way... check out the pic at the bottom. Cut and paste the code block into RStudio.
Multiline comments that make using an IDE more effective are a "Good Thing", most IDEs or simple editors don't have highlighting of text within simple commented -out blocks; though some authors have taken the time to ensure parsing within here-strings. With R we don't have multi-line comments or here-strings either, but using invisible expressions in RStudio gives all that goodness.
As long as there aren't any backticks in the section desired to be used for a multiline comments, here-strings, or non-executed comment blocks then this might be something worth-while.
#### Intro Notes & Comments ####
invisible( expression( `
{ <= put the brace here to reset the auto indenting...
Base <- function()
{ <^~~~~~~~~~~~~~~~ Use the function as a header and nesting marker for the comments
that show up in the jump-menu.
--->8---
}
External <- function()
{
If we used a function similar to:
api_idea <- function() {
some_api_example <- function( nested ) {
stopifnot( some required check here )
}
print("Cut and paste this into RStudio to see the code-chunk quick-jump structure.")
return converted object
}
#### Code. ####
^~~~~~~~~~~~~~~~~~~~~~~~~~ <= Notice that this comment section isnt in the jump menu!
Putting an apostrophe in isn't causes RStudio to parse as text
and needs to be matched prior to nested structure working again.
api_idea2 <- function() {
} # That isn't in the jump-menu, but the one below is...
api_idea3 <- function() {
}
}
# Just to show api_idea isn't really there...
print( api_idea )
}`) )
####
#### Code. ####
foo <- function() {
print( "The above did not evaluate and cause an error!")
}
foo()
## [1] "The above did not evaluate and cause an error!"
And here's the pic...
I can think of two options. The first option is to use an editor that allows to block comment and uncomment (eg. Eclipse). The second option is to use an if statement. But that will only allow you to 'comment' correct R syntax. Hence a good editor is the prefered workaround.
if(FALSE){
#everything in this case is not executed
}
If find it incredible that any language would not cater for this.
This is probably the cleanest workaround:
anything="
first comment line
second comment line
"
Apart from using the overkilled way to comment multi-line codes just by installing RStudio, you can use Notepad++ as it supports the syntax highlighting of R
(Select multi-lines) -> Edit -> Comment/Uncomment -> Toggle Block Comment
Note that you need to save the code as a .R source first (highlighted in red)
I use vim to edit the R script.
Let's say the R script is test.R, containing say "Line 1", "Line 2", and "Line 3" on 3 separate lines.
I open test.R on the command line with Vim by typing "vim test.R".
Then I go to the 1st line I want to comment out, type "Control-V", down arrow to the last line I want to comment out, type a capital I i.e. "I" for insert, type "# ", and then hit the Escape key to add "# " to every line that I selected by arrowing down. Save the file in Vim and then exit Vim by typing ":wq". Changes should show up in Rstudio.
To delete the comments in Vim, start at the first line on top of the character "#" you want to delete, again do "Control-V", and arrow down to the last line you want to delete a "#" from. Then type "dd". The "#" signs should be deleted.
There's seconds-worth of lag time between when changes to test.R in Vim are reflected in Rstudio.
Now there is a workaround, by using package ARTofR or bannerCommenter
Examples here:
In RStudio an easy way to do this is to write your comment and once you have used CTRL + Shift + C to comment your line of code, then use CTRL + SHIFT + / to reflow you comment onto multiple lines for ease of reading.
In RStudio you can use a pound sign and quote like this:
#' This is a comment
Now, every time you hit return you don't need to add the #', RStudio will automatically put that in for you.
Incidentally, for adding parameters and items that are returned, for standardization if you type an # symbol inside those comment strings, RStudio will automatically show you a list of codes associated with those comment parameters:
#' #param tracker_df Dataframe of limit names and limits
#' #param invoice_data Dataframe of invoice data
#' #return return_list List of scores for each limit and rejected invoice rows
Attempting to print out a list of values from 2 different variables that are aligned correctly.
foreach finalList ($correctList $wrongList)
printf "%20s%s\n" $finalList
end
This prints them out an they are aligned, but it's one after another. How would I have it go through each item in each list and THEN go to a new line?
I want them to eventually appear like this:
Correct Incorrect
Good1 Bad1
Good2 Bad2
Good3 Bad3
Good comes from correctList
Bad comes from wrongList
Getting rid of \n makes it Like this:
Good1 Bad1 Good2 Bad2
I just want 2 columns.
You can iterate over both lists at the same time like this:
# Get the max index of the smallest list
set maxIndex = $#correctList
if ( $#wrongList < $#correctList ) then
set maxIndex = $#wrongList
endif
set index = 1
while ($index <= $maxIndex)
printf "%-20s %s\n" "$correctList[$index]" "$wrongList[$index]"
# index++
end
try getting rid of the \n
I believe the pr(1) command with the -m option will help do what you want. Look at its man page to eliminate the header/trailer options and set the column widths.
Also, I recommend you not use the C-Shell for scripting; you'll find the sh-syntax shells (sh, bash, ksh, etc) are more consistent and much easier to debug.