If I understand correctly, you want to count how many 0 values you have in each column? If so, you can use apply function for each of the columns: data <- data.frame( a = c(1,2,0,3), b = c(0,0,0,2) ) apply( data , 2 , function(x) sum ( x == 0 ) ) a b 1 … Read more
You can predict your output by following each step manually. In your case, each func call would work like the following chart: func(5) + +–+ func(4) | + | +–+ func(3) | | + | | +–+ func(2) | | | + | | | +–+ func(1) = 3 | | | | | | … Read more
You seem to have confused if and while. if only runs at most once. while will run any number of times until the condition is false. while num > 2: … 2 solved Did not understand the outputs [closed]
I am coding a game where i have a list of list of buttons and i wish to pass a on click command based on there coordinate in the grid solved I am coding a game where i have a list of list of buttons and i wish to pass a on click command based … Read more
When I run the example code you provided, the application will run. That is to say, the ball (*) will move around the screen. Are you expecting the ball to move on the screen, and the paddle to be drawn and move when an arrow is pressed? If so, you should look at how you … Read more
If the first condition is false then it wont consider the second condition. If first condition is true then it will also evaluate the second condition. This is because you are using && operation. If you use || then if the first one is false it will evaluate the next condition. 4 solved Why is … Read more
You can use the modulus operator (%), this will help make your code future proof, should the 20 need to change to 200 etc for(var i = 1; i <= 20; i++){ if(i % 5 == 0 && i % 3 == 0) { console.log(“FizzBuzz”); } else if (i % 3 == 0) { console.log(“Fizz”); … Read more
$answer = 1; for($x=1;$x<6;$x++){ $answer+=5*$x; } echo $answer; 3 solved How I use for loop to get the addition result? [closed]
The idea that this will form an infinite loop is based on an assumption about how the variables will be laid out in memory. In particular, it assumes that because i is defined immediately after a, that it will also be allocated in memory immediately after a. That’s certainly not guaranteed, but it equally certainly … Read more
What’s the difference between the given two codes. One gives time limit exceeded when run on ideone and the other works fine [closed] solved What’s the difference between the given two codes. One gives time limit exceeded when run on ideone and the other works fine [closed]
There are multiple issues with your current code. You fetch the first row with $row = mysqli_fetch_array($select); (line 3), but you don’t do anything with it. This means that the first result is discarded. Your while loop attempts to loop over an incorrect variable ($query is a string, not the result-object), and you’ve quoted it … Read more
It sounds like you mean this. Some kind of iterative function closing in on a value? #!/usr/bin/env python3 c = 1 d = 1 b = 1 while True: a = 3 * b + c new_b = (a – d) / 5 if b – new_b <= 0.25: break b = new_b print(a, new_b) … Read more
As for your firs question: yes one can make a Python program without using classes or functions at all: all satements are executed in theorder they are encountered 2) you certainly are mixing some concepts there, but generally “yes” – one could stop a loop running in another method if running in parallell to that … Read more
I am interpreting the following to constitute your question. If writing a speed-intensive app that involves lots of calculations as such, should I rely on the optimization by compiler or on register? If multi-thread, will register cause any problem? First of all, if you are aiming for (and trying to measure) efficiency of a program, … Read more
You almost certainly want to replace your specific variables for each nation with a data structure (such as a dictionary) that uses the nation’s name as a key. So, rather than referring to USA_REGION_DATA you’d look up REGION_DATA[“USA”]. This is extensible to any number of nations, as you can simply add new values to the … Read more