combinations

问题 I want to calculate normalised ratios and simple ratios in all possible combinations in R. This is the sample dataset df = structure(list(var_1 = c(0.035, 0.047, 0.004, 0.011, 0.01, 0.01, 0.024), var_2 = c(0.034, 0.047, 0.004, 0.012, 0.01, 0.011, 0.025 ), var_3 = c(0.034, 0.047, 0.006, 0.013, 0.011, 0.013, 0.026), var_4 = c(0.034, 0.046, 0.008, 0.016, 0.014, 0.015, 0.028 ), var_5 = c(0.034, 0.046, 0.009, 0.017, 0.015, 0.016, 0.029 )), class = "data.frame", row.names = c(NA, -7L)) I could able

问题 I have some code which loops through a large set of itertools.combinations , which is now a performance bottleneck. I'm trying to turn to numba 's @jit(nopython=True) to speed it up, but I'm running into some issues. First, it seems numba can't handle itertools.combinations itself, per this small example: import itertools import numpy as np from numba import jit arr = [1, 2, 3] c = 2 @jit(nopython=True) def using_it(arr, c): return itertools.combinations(arr, c) for i in using_it(arr, c):

问题 I want to calculate normalised ratios in all possible combinations efficiently for a large matrix in R. I have asked a similar question earlier here and with a small data and the solutions provided there worked fine. But when I am trying to apply the same solution for a large dataset (400 x 2151), my system is getting hang. My system is having 16 GB RAM with Intel i7 processer. Here is the code with data df <- matrix(rexp(860400), nrow = 400, ncol = 2151) Solution provided by @Ronak Shah cols

问题 I have a code that work right now and lists numbers at 6 lenght.But they are repetive.But these numbers are repeated.I need unique non-repeated 6 digit. I have this kind of results right now.1 1 1 3 4 6 but i need different and non repeating results.Thank you for helping me. Sub AllCombinations() Dim nums(): nums = Array(1, 2, 3, 4, 5, 6, 7, 8, 9) Dim arValues(999999, 5) Dim n1 As Integer, n2 As Integer, n3 As Integer, n4 As Integer, n5 As Integer, n6 As Integer, x As Long For n1 = 0 To

问题 From python's Documentation: https://docs.python.org/2/library/itertools.html#itertools.combinations see combinations_with_replacement: "# combinations_with_replacement('ABC', 2) --> AA AB AC BB BC CC" I'd like to use the same function, with the bonus of generating "BA", "CA", and "CB". 回答1: itertools.product is definitely the method you're looking for here. As the documentation states, it is effectively a compact for loop; product(A,B) is equivalent to ((x, y) for x in A for y in B) product

问题 Lets assume I've got a list of integers: mylist = [101, 102, 103, 104, 105, 106] Now I need to create every possible sublist division (order preserved): sublists = [([101], [102, 103, 104, 105, 106]), ([101, 102], [103, 104, 105, 106]), ([101, 102, 103], [104, 105, 106]), ... ([101, 102], [103, 104], [105, 106]), ... ([101], [102, 103, 104], [105], [106]), ... ([101], [102], [103], [104], [105], [106])] Any idea? Would itertools be helpful? 回答1: You are creating slice points ; are you slicing

问题 I have two sets of options: optionList1 = [a1,a2,a3,...,an] optionList2 = [b1,b2,b3,...,bn] The number of elements in the optionlists are not necessarily equal and I have to choose from the first optionlist twice. How do I ensure that I have tried every combination of 2 options from the first list and one from the second list. An example selection set below... selectedOptions = [an1,an2,bn] 回答1: Assuming you don't want duplicate entries from list1, here's a generator that you can use to

问题 I have two sets of options: optionList1 = [a1,a2,a3,...,an] optionList2 = [b1,b2,b3,...,bn] The number of elements in the optionlists are not necessarily equal and I have to choose from the first optionlist twice. How do I ensure that I have tried every combination of 2 options from the first list and one from the second list. An example selection set below... selectedOptions = [an1,an2,bn] 回答1: Assuming you don't want duplicate entries from list1, here's a generator that you can use to

问题 How can I transform data frames like this one: X__1 X__2 X__3 <chr> <chr> <chr> 1 a b c 2 d e f 3 g h i 4 j k l Into this one: X__1 X__2 X__3 <chr> <chr> <chr> 1 a-d b-e c-f 2 a-g b-h c-i 3 a-j b-k c-l 4 d-g e-h f-i 5 d-j e-k f-l 6 g-j h-k i-l In other words, it should make all possible pairwise combinations of the whole rows in the data frame, combining strings from the same column but separated by a sign(-). It does not need to repeat an already made combination in the other order of

问题 I have an array of objects with the following structure: var varientSections = [ { type: "frame", values: ["black", "white", "wood"] }, { type: "finish", values: ["matte", "glossy"] } ]; I want to get the combination of the array values and create a new list with it. Right now, I am able to retrieve the combination from the nested array values using the method called getCombination(varientSections) . However, I do not know how to create a new list with the following structure: var results = [