I have a dataframe that looks like this: df <- data.frame(sample = c(1,2,3,4), code = c("D", "B", "A", "B")) I also have two vectors that look like this: code <- c("A", "B", "C") name <- c("Apple", "Bat", "Cat") I know if I wanted to use the vectors to assign a "name" based on a matching… Read More R: assign dataframe column values using external vectors

I want to create a data frame from a series of vectors that I have named like d*i*. I attempted to do this using the paste function, but it just built a data frame with a single column with values "d1, d2, d3…" I want to put the vectors associated with those variable names in.… Read More In R, how to quickly create dataframe from a series of variables with indexed name?

I researched the error and haven’t been able to find it. Also I am new to this. I want to learn the basics of C and here is my first program. I want to modify sum in the function calc so it is a float in case someone divides for example 2/5. #include <stdio.h> int… Read More "conversion to 'float' from 'int' may alter its value"

I have the following method and I get a unused_assignment warning for let mut res = 1.0: fn my_func(pld: &f64, lambda: &[f64;NUMF]) -> [f64;NUMF] { let mut result = [0.0; NUMF]; for i in 0..NUMF{ let pdrel = pld / lambda[i]; let mut res = 1.0; if pdrel >= 0.0 { res = 1.0; }… Read More Why unused_assignment before if statment?

CONTEXT I’m creating a calculator. I’m at the point where I want my calculator to do BODMAS (start calculations with the inner most bracket). The user enters an expression, in this example it is: expression = (1+(1+1)) I have a function that splits up this function into ‘terms’ and saves the result in expression_list. expression_list… Read More Dictionary Assignment Not Functioning As Intended

I am trying to display a Form Widget 2ithin a Dialog as following: onPressed: () async { switch (currentScreen.toString()) { case ‘OverviewScreen’: () => showDialog( context: context, builder: const Dialog(child: FormBasicDetails())); break; } }, But I get the following error at the builder line: The argument type ‘Dialog’ can’t be assigned to the parameter type… Read More The argument type 'Dialog' can't be assigned to the parameter type 'Widget Function(BuildContext)'

Can someone help me while writing an assignment? It is necessary to create a template for creating objects of the Student type. Each Student should have the following properties: It is necessary to create a template for creating objects of type Student. Every student should have the following characteristics: name, address, phone, course, index_number. Each… Read More Problem with writing an objective oriented python assignment

I’ve spent some time trying to understand some C++ code, and I have background in C and Java. The code in question used what looked to be shorthand of some kind that I didn’t recognize or understand for some time. I know now that they were using assignment constructors to assign variables, something that doesn’t… Read More What's the difference between using an Assignment Constructor vs. normal assignment here?

Consider this task : With a one line command save all usernames transformed into CAPITALS in a bash array called USERNAMES. Capitalize using bash variable expansion. If not for the the one line limitation, I would just use USERNAMES=($(ls /home)) # simplified for purposes of this question, returns (user1 user2 …) USERNAMES=(${USERNAMES[*]^^}) # must return… Read More Expand the output of the command and only then assign it to a variable

I have an variable: $a = sfd. If I use New-Item ‘1’$a, then it will yield this error: New-Item: A positional parameter cannot be found that accepts argument ‘sdf’. But if I use New-Item "1$a" then it works. According to How do I concatenate strings and variables in PowerShell? both two methods should work. Do… Read More Why does using single quotes with variables yield error "A positional parameter cannot be found that accepts argument"?