counter

问题 I'm new to sparql and trying to fegure out what is the best way to select the max value of a counter of another query without creating a new table, only using sub-queries. I'm working on a relatively small dataset so the computation time is not a problem. SELECT ?p1 ?c1 (MAX(?cnt1) AS ?maxc) WHERE{ { SELECT ?p1 ?c1 (COUNT(?s1) AS ?cnt1) WHERE { ?s1 ?p1 ?o1; a ?c1. }Group by ?p1 ?c1 #ORDER BY ?p1 DESC(?cnt1) } }GROUP BY ?p1 so I'm expecting to get a row for every value of ?p1 with the max

问题 In Hadoop we can increment counter in map/reduce task, it looks like this: ... context.getCounter(MyCountersEnum.SomeCounter).increment(1); ... Than you can find their value in log. How do you access them from code after job completes? What is Hadoop API to read counter value? 回答1: Counters represent global counters , defined either by the Map-Reduce framework or applications. Each Counter can be of any Enum type. You can define counter as an enum in Driver class static enum UpdateCount{ CNT

问题 Is there a way to create a COUNTER() macro (which follows the C++11/14 standard) that is expanded to a number which increases by one every time COUNTER() is invoked? I've thought about it, but couldn't find a way to make it work. I didn't find a way to store "state" in the COUNTER() macro. Example: #define COUNTER() <...> // Implementation goes here... #define UNIQUE_NAME_1() TEST ## COUNTER() #define UNIQUE_NAME_2() TEST ## COUNTER() // Note how the COUNTER() macro can be used with other

问题 Can I include an additional counter in a MySQL result set? I have the following query which gives me two columns back. I need an additional column (only in the result) indicating the row of each line in the result set. select orderid, round(sum(unitprice * quantity),2) as value from order_details group by orderid order by 2 desc limit 10 I need something like the following: 10865 1 17250.00 11030 2 16321.90 10981 3 15810.00 10372 4 12281.20 10424 5 11493.20 回答1: Try this: SET @counter = 0;

问题 Can I include an additional counter in a MySQL result set? I have the following query which gives me two columns back. I need an additional column (only in the result) indicating the row of each line in the result set. select orderid, round(sum(unitprice * quantity),2) as value from order_details group by orderid order by 2 desc limit 10 I need something like the following: 10865 1 17250.00 11030 2 16321.90 10981 3 15810.00 10372 4 12281.20 10424 5 11493.20 回答1: Try this: SET @counter = 0;

问题 I have a problem filtering a pandas dataframe. city NYC NYC NYC NYC SYD SYD SEL SEL ... df.city.value_counts() I would like to remove rows of cities that has less than 4 count frequency , which would be SYD and SEL for instance. What would be the way to do so without manually dropping them city by city? 回答1: Here you go with filter df.groupby('city').filter(lambda x : len(x)>3) Out[1743]: city 0 NYC 1 NYC 2 NYC 3 NYC Solution two transform sub_df = df[df.groupby('city').city.transform('count'

问题 I am trying to figure out the fastest way to access data stored in a junction object. The example below is analagous to my problem, but with a different context, because the actual dataset I am dealing with is somewhat unintuitive in its relationships. We have 3 classes: User , Product , and Rating . User has a many-to-many relationship to Product with Rating as the junction/'through' class. The Rating object stores the answers to several questions which are integer ratings on a scale of 1-5

问题 I have a counter which animates to a final number which is defined in the HTML. However I would like this animation to happen once it's in the viewport. I have a fiddle here which shows how scrolling seems to effect the counter number. $(document).ready(function() { $(function($, win) { $.fn.inViewport = function(cb) { return this.each(function(i, el) { function visPx() { var H = $(this).height(), r = el.getBoundingClientRect(), t = r.top, b = r.bottom; return cb.call(el, Math.max(0, t > 0 ?

问题 What is the complexity of the function most_common provided by the collections.Counter object in Python? More specifically, is Counter keeping some kind of sorted list while it's counting, allowing it to perform the most_common operation faster than O(n) when n is the number of (unique) items added to the counter? For you information, I am processing some large amount of text data trying to find the n-th most frequent tokens. I checked the official documentation and the TimeComplexity article

问题 I obtained very surprising results with timeit, can someone tell me if I am doing something wrong ? I am using Python 2.7. This is the contents of file speedtest_init.py: import random to_count = [random.randint(0, 100) for r in range(60)] These are the contents of speedtest.py: __author__ = 'BlueTrin' import timeit def test_init1(): print(timeit.timeit('import speedtest_init')) def test_counter1(): s = """\ d = defaultdict(int); for i in speedtest_init.to_count: d[i] += 1 """ print(timeit