max

问题 I have a character string and need to find the word in the string that occurs most frequently. I've tried every variation of max , which.max , sort , order , and rank that I can think of - but can't seem to get the syntax worked out correctly. I've also tried all of the methods found here: Calculate frequency of occurrence in an array using R Example code: zzz <- c("jan", "feb", "jan", "mar", "mar", "jan", "feb") #random example data zzz <- paste(zzz, collapse=" ") #make data look like what I

问题 I have read much in textbooks and browsed a lot of pages on the internet but I can't understand how functions/operators like min, max, count, ... that aggregate over a relation/table or groups of tuples/rows in a relation/table are built with basic operations such as ∪ (union), ∩ (intersection), x (join), - (minus), π (projection), .... Can anyone show me how to express these functions/operators with relational algebra? 回答1: Computing functions in relation algebra are not fully included yet.

问题 I have read much in textbooks and browsed a lot of pages on the internet but I can't understand how functions/operators like min, max, count, ... that aggregate over a relation/table or groups of tuples/rows in a relation/table are built with basic operations such as ∪ (union), ∩ (intersection), x (join), - (minus), π (projection), .... Can anyone show me how to express these functions/operators with relational algebra? 回答1: Computing functions in relation algebra are not fully included yet.

问题 Given a 2-dimensional array of positive integers, find the subrectangle of size HxW with the largest sum. The sum of a rectangle is the sum of all the elements in that rectangle. Input: A 2D array NxN with positive elements The HxW size of the subrectangle Output: The submatrix of HxW size with the largest sum of its elements. I've solved this using a brute-force method, however, I'm now looking for a better solution with better complexity (my brute-force method's complexity is O(n 6 )). 回答1:

问题 I have a List<List<double>> and I need to find a List MyList where MyList[0], for instance, is the Max of all the first elements of the List. Example, just to be clear: First list contains (3,5,1), second contains (5,1,8), third contains (3,3,3), fourt contains (2,0,4). I need to find a list with (5, 5, 8). I do NOT need the list (5,8,3,4). Of course i know how to do it with nested for cycles. I'd like to know if there's a linq way and believe me i don't know where to start from. 回答1: Try

问题 I have a List<List<double>> and I need to find a List MyList where MyList[0], for instance, is the Max of all the first elements of the List. Example, just to be clear: First list contains (3,5,1), second contains (5,1,8), third contains (3,3,3), fourt contains (2,0,4). I need to find a list with (5, 5, 8). I do NOT need the list (5,8,3,4). Of course i know how to do it with nested for cycles. I'd like to know if there's a linq way and believe me i don't know where to start from. 回答1: Try

问题 I am trying to dynamically allocate an array of doubles and set each element to a random value within a range of positive or negative numbers, but I am having difficulty. Right now, I can only figure out how to set numbers 0 - max. Here is what I have so far: double *random_arr(int size, double min, double max) { double *array0 = calloc(size, sizeof(double)); if (array0 == NULL) { exit(1); } for (int i = 0; i < size; i++) array0[i] = (max * rand() / RAND_MAX); return array0; } My best guess:

问题 I am trying to dynamically allocate an array of doubles and set each element to a random value within a range of positive or negative numbers, but I am having difficulty. Right now, I can only figure out how to set numbers 0 - max. Here is what I have so far: double *random_arr(int size, double min, double max) { double *array0 = calloc(size, sizeof(double)); if (array0 == NULL) { exit(1); } for (int i = 0; i < size; i++) array0[i] = (max * rand() / RAND_MAX); return array0; } My best guess:

问题 Like the title says. I am having trouble. for example I have a 2 column (V1,V2) dataframe with lots of rows, around 300,000. I know that max(df$V2) will give me the max value of that second column. Now that I know my max value, how can I get the entire row associated with that value. Thanks! 回答1: You have to write df[which.max(df$V2), ] If more than one row contains the max: i <- max(df$V2) df[which(df$V2 == i), ] 来源： https://stackoverflow.com/questions/36802736/trying-to-find-row-associated

问题 i need to print out average height from a .txt file. How do I write it in an easy way? The .txt file has these numbers: 12 14 59 48 45 12 47 65 152 this is what i've got so far: import math text = open(r'stuff.txt').read() data = [] with open(r'stuff.txt') as f: for line in f: fields = line.split() rowdata = map(float, fields) data.extend(rowdata) biggest = min(data) smallest = max(data) print(biggest - smallest) 回答1: To compute the average of some numbers, you should sum them up and then