max

问题 I have an array of three element like [31,23,12] and I want to find the second largest element and its related position without rearranging the array . Example : array = [21,23,34] Second_largest = 23; Position is = 1; 回答1: Make a clone of your original array using .slice(0) like : var temp_arr = arr.slice(0); Then sor it so you get the second largest value at the index temp_arr.length - 2 of your array : temp_arr.sort()[temp_arr.length - 2] Now you could use indexOf() function to get the

问题 I have a matlab function that returns the utility value U(h1, h2) that depends on the number of work hours for two persons h1 and h2 . Each person can work at maximum 3500 hours. How do I write this code in the best way? For only one person I only loop the function from input value 0 to 3500 into a matrix and find the max value in the matrix. But now I have two values that can take the value 0 to 3500 and want to find the max output from the function based on these values. I would be very

问题 I am trying to find the maximum of the following function for 1 < R < 20. How can I implement this into the code? The solution is supposed to be R is approx 15.5 or so. #!/usr/bin/env python # Plotting the energy for circular Hohmann transfer import scipy import matplotlib import numpy as np import pylab def f(R): return 1 / np.sqrt(R) - (np.sqrt(2) * (1 - R)) / (np.sqrt(2) * (1 + R)) - 1 x = np.arange(1, 20) pylab.plot(x, f(x), 'r') pylab.show() 回答1: You can use scipy.optimizie.fmin : >>>

问题 When I attempt to do something like SELECT Max(ObjectId) FROM Objects; I see that in the explain-plan that this is performed by doing a sort. Now, sorting (which I guess would require something in the complexity of O(nlogn) ) must be much costlier than just scanning each row and remembering the max value (which could be done in O(n) ). Am I missing something here? Is oracle really performing a sort or does the explain-plan just use the description "sort" for describing a simple scan of all

问题 Given an amount of sets with numbers (0-20 e.g) , we are asked to find the maximum set of numbers from 0-20 that doesn't include any of the given sets(it can include numbers from a set,but not the whole set) For example :Setting the max number 8 and given the sets {1,2} {2,3} {7} {3,4} {5,6,4}, one maximum solution is the set {1, 3, 5, 6, 8}. I was thinking of representing it as a graph and then inducting it to the Max Independent Set problem, but that seems to work only if the sets were

问题 I want to be able to get all the data from table 1 and table 3 below but in addition to this I also want to get the latest application stage from table 2. The latest application stage is determined by getting the max stage_date for each application. Table 1: applications id | applicant_id | col_x | col_y | col_z ----------------------------------------- 10 300 a b c 11 310 a b c 12 320 a b c 13 330 a b c 14 340 a b c Table 2: application_progress id | application_id | application_stage |

问题 I have a script to pull random numbers from a set of values. However, it broke today because min() and max() sort values by lexicographic order (so 200 is considered greater than 10000). How can I avoid lexicographic order here? Len key is on the right track but not quite right. I couldn't find any other key(s) that would help. data_set = 1600.csv, 2405.csv, 6800.csv, 10000.csv, 21005.csv First try: highest_value = os.path.splitext(max(data_set))[0] lowest_value = os.path.splitext(min(data

问题 I am looking for a solution to SELECT (or otherwise derive) the values for Column C (minimum price for last 3 days only, not for the whole column). ---------------------------------------- Date | Unit_ | Low_3_days | | price | | ---------------------------------------- 2015-01-01 | 15 | should be: 15 | 2015-01-02 | 17 | should be: 15 | 2015-01-03 | 21 | should be: 15 | 2015-01-04 | 18 | should be: 17 | 2015-01-05 | 12 | should be: 12 | 2015-01-06 | 14 | should be: 12 | 2015-01-07 | 16 |

问题 I have excel sheet data like below CustomerNo LoginDate 101 25/05/2012 101 10/05/2012 101 20/05/2012 101 10/04/2012 102 21/05/2012 102 12/04/2012 103 20/05/2012 104 08/04/2012 I want to get last login date match with customer number and result like below. 101 25/05/2012 102 21/05/2012 103 20/05/2012 104 08/04/2012 回答1: You may use the DMAX function to do this. First, I am putting CustomerNo in A1 and 08/04/2012 in B9. Then I am naming that range "theTable". Second, I add A11 and B11 my

问题 I have a df with columns X1, Y1, Z3. df.describe shows the stats for each column I would like to extract the min, max and std for say column Z3. df[df.z3].idxmax() doesn't seem to work 回答1: Demo: In [7]: df = pd.DataFrame(np.random.rand(10, 3), columns=['X1','Y1','Z3']) In [8]: df Out[8]: X1 Y1 Z3 0 0.258116 0.667943 0.954830 1 0.584975 0.546284 0.045745 2 0.698974 0.409223 0.307409 3 0.073166 0.356393 0.722233 4 0.339093 0.146043 0.614686 5 0.624361 0.062805 0.574546 6 0.886631 0.217291 0