loops

问题 I have the following test that is printing the original input slice (after the filtering) without the element that has been removed, but with an extra element at the end making the input slice of the same length, even if after the filtering it should be shorter. I've gone through this doc https://github.com/golang/go/wiki/SliceTricks#delete However I think I am missing some gotchas about Go, because it seems I am using slices with the wrong approach. how can I avoid to have an "output slice"?

问题 Basically I want to stop a function but not by terminating the script. While True: do function A() do function B() if ( condition ): function B.stop() What I mean is when the condition is met, the while loop still runs but in the next iteration of the while loop, it only does function A, no longer does it do function B. I wonder if we can archive this in python? Thanks 回答1: How about using a flag within the loop flag = True while True: if flag: do function B() if condition: flag = false 回答2:

问题 I am using the pROC package in r to calculate and compare the AUCs of multiple tests, to see which test has the best ability to discriminate between patients and controls. However, I have a large number of tests and essentially want to run a series of pairwise comparisons of each tests AUC with every other test and then correct for multiple comparisons. This is as far as I've gotten with my code (example with simulated and replicable dataset below): #load pROC library(pROC) #generate df with

问题 Im quite stuck here. I have been trying and googling for the past 2 days but I cant figure it out. I have a class that is called Player and another that is called Enemy that inherits from Player. I have a list that stores coordinates for my bullets and loop trough them in Player. Im trying to access and loop trough the same list to check for collision in Enemy that builds on Player, but It will not even enter the loop. I guess somehow its empty but why? struct structShoot { float x; float y;

问题 I have a foreach loop that I would like to execute a prepare statement pdo. I have read a few posts on making a reference but I do not know how to do it with my code: $str = ":City, Aurora; :State, CO"; $wherestr = explode(";",$str); $sql = "SELECT * FROM Organization WHERE City = :City AND State= :State"; $stmt = $db->prepare($sql); foreach ($wherestr as $ws) { $ws = explode(",",$ws); $ws0 = trim($ws[0]); $ws1 = trim($ws[1]); $stmt->bindParam($ws0,$ws1); } $stmt->execute(); I have read here

问题 May be this is too simple of a question but I couldn't find a functional answer. How can we extract the opposite diagonal elements of any square matrix in R? In the example below that would be: 7, 2, 8 . r <- matrix(c(1, 5, 8, 1:3, 7:9), 3) 回答1: An approach could be r[(n<-nrow(r))^2-(1:n)*(n-1)] # [1] 7 2 8 ## microbenchmark (matrix(1:1e6,1000)) # Unit: microseconds # expr min lq mean median uq max neval # r[(n<-nr... 26.897 39.0075 65.36835 47.309 85.9345 316.97 100 # diag(r[,... 18070.388

问题 May be this is too simple of a question but I couldn't find a functional answer. How can we extract the opposite diagonal elements of any square matrix in R? In the example below that would be: 7, 2, 8 . r <- matrix(c(1, 5, 8, 1:3, 7:9), 3) 回答1: An approach could be r[(n<-nrow(r))^2-(1:n)*(n-1)] # [1] 7 2 8 ## microbenchmark (matrix(1:1e6,1000)) # Unit: microseconds # expr min lq mean median uq max neval # r[(n<-nr... 26.897 39.0075 65.36835 47.309 85.9345 316.97 100 # diag(r[,... 18070.388

问题 It's well-known that break and continue can be used inside a loop: for (let i = 0; i < 5; i++) { console.log(i); if (i === 3) { break; } } Is there any way to those in just an if statement instead, outside a loop, to break out of or restart the if statement? 回答1: The answer is different for break (yes) and continue (no). break You can use break in an if , yes, if you label the if . I wouldn't , but you can : foo: if (true) { console.log("In if before break"); break foo; console.log("In if

问题 I have data on all the NCAA basketball games that have occurred since 2003. I am trying to implement a for loop that will calculate the average of a number of stats for each time at a point in time. Here is my for loop: library(data.table) roll_season_team_stats <- NULL for (i in 0:max(stats_DT$DayNum)) { stats <- stats_DT[DayNum < i] roll_stats <- dcast(stats_DT, TeamID+Season~.,fun=mean,na.rm=T,value.var = c('FGM', 'FGA', 'FGM3', 'FGA3', 'FTM', 'FTA', 'OR', 'DR', 'TO')) roll_stats$DayNum <-

问题 This question already has answers here : Group by DataFrame with list and sum (2 answers) Closed 4 days ago . I have a df that looks like this: var1 var2 var3 0 a 1 0 b 7 0 c 5 0 d 4 0 z 8 1 t 9 1 a 2 2 p 3 .. .. .. 60 c 3 I'm attempting to create lists of each set of values from var2 that correspond to a given value from var1 . So, my output would look something like this: list_0: a, b, c, d, z list_1: t, a list_2: p list_60: c Currently I'm trying to work out a loop to do this, something