for-loop

问题 I wrote some code to break up a for loop into multiple processes to speed up calculations. import numpy as np import formfactors from subdivide_loop import subdivide_loop import multiprocessing def worker(start, end, triangleI, areaI, scene, kdtree, samples, output): form_factors = np.zeros(end-start) for j in range(start, end): triangleJ = np.array(scene[j][0:4]) form_factors[start] = formfactors.uniform(triangleJ, triangleI, areaI, kdtree, samples) result = output.get(block=True) for j in

问题 Currently making a minesweeper game and stuck on being able to loop through the 8 surrounding cells to find the number of surrounding bombs. I have a helper method that I believe works fine that is used to check if the cell (passed by numberOfAdjacentBombs) contains a bomb. How do I go about creating a nested for loop that will loop through each surrounding cell? e.g (row-1, col-1), (row-1, col), (row-1, col+1). Any help or hints is appreciated, thanks! :-) private int numberOfAdjacentBombs

问题 for (let x of a) does not work in IE11. Can I replace it by for (let x in a) ? for (let key in a) { s += key + ": " + a[key]; s += "<br />"; } for (let key of a) { s += key + ": " + a[key]; s += "<br />"; } 回答1: for...of is not supported in IE11 yet. You can use for..in to iterate over as it has the support from IE6. If you just want to add the key and value , you can use Object.keys and build the string that is needed. let f = ''; let s = ''; let a = { firstName: 'Hello', lastName: 'JS',

问题 I have a simple for loop iterating over a list of items. At some point, I know it will break. How can I then return the remaining items? for i in [a,b,c,d,e,f,g]: try: some_func(i) except: return(remaining_items) # if some_func fails i.e. for c I want to return [c,d,e,f,g] I know I could just take my inital list and delete the the items from the beginning for every iteration one by one. But is there maybe some native Python function for this or something more elegant? 回答1: You can make use of

问题 I have the following function: position_tab <- filter(Tall, Time_point == 2) %>% group_by(Object) %>% summarise(minimum = min(Pixel_pos), maximum = max(Pixel_pos)) position_tab_2 <- mutate(position_tab, midpoint = minimum + ((maximum - minimum)/2)) Which produces: Object minimum maximum midpoint 1 4 22 13 2 39 85 62 etc.. This is filtering for a given timepoint, and creating a new dataframe with the midpoint variable added. Is there a way to loop this in increments of + one, so that the

问题 I have the following function: position_tab <- filter(Tall, Time_point == 2) %>% group_by(Object) %>% summarise(minimum = min(Pixel_pos), maximum = max(Pixel_pos)) position_tab_2 <- mutate(position_tab, midpoint = minimum + ((maximum - minimum)/2)) Which produces: Object minimum maximum midpoint 1 4 22 13 2 39 85 62 etc.. This is filtering for a given timepoint, and creating a new dataframe with the midpoint variable added. Is there a way to loop this in increments of + one, so that the

问题 For the following code I want to optimize it using the pattern introduced in this solution. However, the problem is how to deal with referring to three nested loops in a single statement. Moreover, the condition is far different from that post. hint: W and S are NxN sparse double matrices. for i=1:N for j=1:N for k=1:N if W(j,k)~=0 temp(k)=S(i,j)-S(i,k); end end sum_temp=max(temp)+sum_temp; temp=0; end B(i,i)=sum_temp; sum_temp=0; end 回答1: In this situation I would opt against fully

问题 This is a sample of my data set: day city count 1 1 A 50 2 2 A 100 3 2 B 110 4 2 C 90 Here is the code for reproducing it: df <- data.frame( day = c(1,2,2,2), city = c("A","A","B","C"), count = c(50,100,110,90) ) As you could see, the count data is missing for city B and C on the day 1. What I want to do is to use city A's count as an estimate for the other two cities. So the desired output would be: day city count 1 1 A 50 2 1 B 50 3 1 C 50 4 2 A 100 5 2 B 110 6 2 C 90 I could come up with a

问题 I am curious to understand how Python for loops work under the hood. I tried to implement it somewhat like the following code snippet, is that how the for loop has been implemented? my_list = [1, 2, 3, 4, 5] # list itself is iterable but not iterator. Make it an iterator iter_list = iter(my_list) while True: try: print(next(iter_list)) except StopIteration: break 回答1: Yes, that's a good approximation of how the for loop construct is implemented. It certainly matches the for loop statement

问题 import java.util.Scanner; public class Problem1{ public static void main(String[] args){ //input Scanner kb = new Scanner(System.in); String word,letter; int counter=0, match,value; word=kb.next(); word=word.toLowerCase(); letter=kb.next(); letter=letter.toLowerCase(); //loop for (int i=0;i<word.length();i++) if (word.charAt(i)==letter.charAt(0)){ counter++; match=i; System.out.print(match); } if (counter==0) System.out.print(-1); } } I must execute this program in Codio. This program will