duplicates

I have an array a as follows: a = [ 1 2; 3 4; 1 2 ]; I want to delete all rows appearing more than once in a and get c : c = [ 3 4 ]; Please note that this is not the same operation as keeping unique rows, since I don't want rows that had duplicates to appear at all. How can I accomplish this? The third output of unique gives you the index of the unique row in the original array. You can use this with accumarray to count the number of occurrences, which can be used to select rows that occur only once. For example: A = [1 2; 3 4; 1 2]; [uniquerow, ~, rowidx] = unique(A, 'rows'); noccurrences =

I have a function that gets all neighbours of a list of points in a grid out to a certain distance, which involves a lot of duplicates (my neighbour's neighbour == me again). I've been experimenting with a couple of different solutions, but I have no idea which is the more efficient. Below is some code demonstrating two solutions running side by side, one using std::vector sort-unique-erase, the other using std::copy into a std::unordered_set. I also tried another solution, which is to pass the vector containing the neighbours so far to the neighbour function, which will use std::find to

I have data in the following format called DF (this is just a made up simplified sample): eval.num, eval.count, fitness, fitness.mean, green.h.0, green.v.0, offset.0 random 1 1 1500 1500 100 120 40 232342 2 2 1000 1250 100 120 40 11843 3 3 1250 1250 100 120 40 981340234 4 4 1000 1187.5 100 120 40 4363453 5 1 2000 2000 200 100 40 345902 6 1 3000 3000 150 90 10 943 7 1 2000 2000 90 90 100 9304358 8 2 1800 1900 90 90 100 284333 However, the eval.count column is incorrect and I need to fix it. It should report the number of rows with the same values for (green.h.0, green.v.0, and offset.0) by only

I have a list of tuples and I need to delete tuples containing same elements. d=[(1,0),(2,3),(3,2),(0,1)] OutputRequired=[(1,0),(2,3)] Order of output doesn't matter command set() doesn't work as expected. In this solution, I am copying each of the tuples into a temp after checking whether it is already present in the temp and then copy back to d . d = [(1,0),(2,3),(3,2),(0,1)] temp = [] for a,b in d : if (a,b) not in temp and (b,a) not in temp: #to check for the duplicate tuples temp.append((a,b)) d = temp * 1 #copy temp to d This will give the output as expected. 来源： https://stackoverflow

I am trying to concatenate a few fields into a single one, but only keep unique values in the resulting string. Example: title_orig | title_fr | title_de | title_it --------------------------------------------------------------------- KANDAHAR | KANDAHAR | REISE NACH KANDAHAR | VIAGGO A KANDAHAR SCREAM 2 | SCREAM 2 | SCREAM 2 | SCREAM 2 With CONCAT_WS(', ', title_orig, title_fr, title_de, title_it) AS titles I would get titles ------------------------------------------------------------ KANDAHAR, KANDAHAR, REISE NACH KANDAHAR, VIAGGO A KANDAHAR SCREAM 2, SCREAM 2, SCREAM 2, SCREAM 2 But I

I connect with user "root" onto my database "test" which I host locally for development. Among others I have the table "ratingcomment". For some reason when I click on the table "ratingcomment" phpMyAdmin shows me the following error: Fehler SQL-Befehl: INSERT INTO `phpmyadmin`.`pma_history` ( `username` , `db` , `table` , `timevalue` , `sqlquery` ) VALUES ( 'root', 'test', 'ratingcomment', NOW( ) , 'SELECT * FROM `ratingcomment`' ) MySQL meldet: #1062 - Duplicate entry '838' for key 'PRIMARY' I used google to finde out the following "This indicates that you have a UNIQUE or PRIMARY index on a