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• How to exit current activity to homescreen (without using "Home" button)?

  - by steff

  Hi everyone, I am sure this will have been answered but I proved unable to find it. So please excuse my redundancy. What I am trying to do is emulating the "Home" button which takes one back to Android's homescreen. So here is what causes me problems: I have 3 launcher activities. The first one (which is connected to the homescreen icon) is just a (password protected) configuration activity. It will not be used by the user (just admin) One of the other 2 (both accessed via an app widget) is a questionnaire app. I'm allowing to jump back between questions via the Back button or a GUI back button as well. When the questionnaire is finished I sum up the answers given and provide a "Finish" button which should take the user back to the home screen. For the questionnaire app I use a single activity (called ItemActivity) which calls itself (is that recursion as well when using intents?) to jump from one question to another: Questionnaire.serializeToXML(); Intent i = new Intent().setClass(c, ItemActivity.class); if(Questionnaire.instance.getCurrentItemNo() == Questionnaire.instance.getAmountOfItems()) { Questionnaire.instance.setCompleted(true); } else Questionnaire.instance.nextItem(); startActivity(i); The final screen shows something like "Thank you for participating" as well as the formerly described button which should take one back to the homescreen. But I don't really get how to exit the Activity properly. I've e.g. used this.finish(); but this strangely brings up the "Thank you" screen again. So how can I just exit by jumping back to the homescreen?? Sorry for the inconvinience. Regards, Steff

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• Better way to summarize data about stop times?

  - by Vimvq1987

  This question is close to this: http://stackoverflow.com/questions/2947963/find-the-period-of-over-speed Here's my table: Longtitude Latitude Velocity Time 102 401 40 2010-06-01 10:22:34.000 103 403 50 2010-06-01 10:40:00.000 104 405 0 2010-06-01 11:00:03.000 104 405 0 2010-06-01 11:10:05.000 105 406 35 2010-06-01 11:15:30.000 106 403 60 2010-06-01 11:20:00.000 108 404 70 2010-06-01 11:30:05.000 109 405 0 2010-06-01 11:35:00.000 109 405 0 2010-06-01 11:40:00.000 105 407 40 2010-06-01 11:50:00.000 104 406 30 2010-06-01 12:00:00.000 101 409 50 2010-06-01 12:05:30.000 104 405 0 2010-06-01 11:05:30.000 I want to summarize times when vehicle had stopped (velocity = 0), include: it had stopped since "when" to "when" in how much minutes, how many times it stopped and how much time it stopped. I wrote this query to do it: select longtitude, latitude, MIN(time), MAX(time), DATEDIFF(minute, MIN(Time), MAX(time)) as Timespan from table_1 where velocity = 0 group by longtitude,latitude select DATEDIFF(minute, MIN(Time), MAX(time)) as minute into #temp3 from table_1 where velocity = 0 group by longtitude,latitude select COUNT(*) as [number]from #temp select SUM(minute) as [totaltime] from #temp3 drop table #temp This query return: longtitude latitude (No column name) (No column name) Timespan 104 405 2010-06-01 11:00:03.000 2010-06-01 11:10:05.000 10 109 405 2010-06-01 11:35:00.000 2010-06-01 11:40:00.000 5 number 2 totaltime 15 You can see, it works fine, but I really don't like the #temp table. Is there anyway to query this without use a temp table? Thank you.

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• SQL Query Math Gymnastics

  - by keruilin

  I have two tables of concern here: users and race_weeks. User has many race_weeks, and race_week belongs to User. Therefore, user_id is a fk in the race_weeks table. I need to perform some challenging math on fields in the race_weeks table in order to return users with the most all-time points. Here are the fields that we need to manipulate in the race_weeks table. races_won (int) races_lost (int) races_tied (int) points_won (int, pos or neg) recordable_type(varchar, Robots can race, but we're only concerned about type 'User') Just so that you fully understand the business logic at work here, over the course of a week a user can participate in many races. The race_week record represents the summary results of the user's races for that week. A user is considered active for the week if races_won, races_lost, or races_tied is greater than 0. Otherwise the user is inactive. So here's what we need to do in our query in order to return users with the most points won (actually net_points_won): Calculate each user's net_points_won (not a field in the DB). To calculate net_points, you take (1000 * count_of_active_weeks) - sum(points__won). (Why 1000? Just imagine that every week the user is spotted a 1000 points to compete and enter races. We want to factor-out what we spot the user because the user could enter only one race for the week for 100 points, and be sitting on 900, which we would skew who actually EARNED the most points.) This one is a little convoluted, so let me know if I can clarify further.

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• MS Query returns data inside itself but does not export it to Excel

  - by kappa

  Hi, I'm having a strange problem with Excel and MS Query: I'm using MS Query to run a T-SQL query against a Microsoft SQL Server 2000 and return the results to Excel. To do this, I open Excel, go to Data - Import external data - New database query, select my data source, paste the SQL script in MS Query and click File - Return data to Microsoft Office Excel, leaving all the query options to their defaults. This works fine for many other Excel files, but this time although MS Query shows the correct data when I paste the SQL script, after returning to Excel all I get is the query name in the upper left cell, with no data returned. I fear the cause could be the SQL script, as it contains some advanced functions like union all, UDFs and variables. Here's the script: declare @date smalldatetime set @date = dateadd(day, datediff(day, 0, getdate()), 0) select [date], sum([hours]) as [hours] from ( select [date], [hours] from [server].[dbo].[udf] (84, '2010-01-01', @date) union all select [date], [hours] from [server].[dbo].[udf] (89, '2010-01-01', @date) union all select [date], [hours] from [server].[dbo].[udf] (93, '2010-01-01', @date) ) as [a] group by [date] order by [date] asc I can't get rid of the UDF as inside them are done advanced groupings involving cursors and temporary tables, nor I can remove the variable as the UDF won't accept dateadd(day, datediff(day, 0, getdate()), 0) as parameter. Any ideas? Thanks in advance, Andrea.

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• Correlate GROUP BY and LEFT JOIN on multiple criteria to show latest record?

  - by Sunbird

  In a simple stock management database, quantity of new stock is added and shipped until quantity reaches zero. Each stock movement is assigned a reference, only the latest reference is used. In the example provided, the latest references are never shown, the stock ID's 1,4 should have references charlie, foxtrot respectively, but instead show alpha, delta. How can a GROUP BY and LEFT JOIN on multiple criteria be correlated to show the latest record? http://sqlfiddle.com/#!2/6bf37/107 CREATE TABLE stock ( id tinyint PRIMARY KEY, quantity int, parent_id tinyint ); CREATE TABLE stock_reference ( id tinyint PRIMARY KEY, stock_id tinyint, stock_reference_type_id tinyint, reference varchar(50) ); CREATE TABLE stock_reference_type ( id tinyint PRIMARY KEY, name varchar(50) ); INSERT INTO stock VALUES (1, 10, 1), (2, -5, 1), (3, -5, 1), (4, 20, 4), (5, -10, 4), (6, -5, 4); INSERT INTO stock_reference VALUES (1, 1, 1, 'Alpha'), (2, 2, 1, 'Beta'), (3, 3, 1, 'Charlie'), (4, 4, 1, 'Delta'), (5, 5, 1, 'Echo'), (6, 6, 1, 'Foxtrot'); INSERT INTO stock_reference_type VALUES (1, 'Customer Reference'); SELECT stock.id, SUM(stock.quantity) as quantity, customer.reference FROM stock LEFT JOIN stock_reference AS customer ON stock.id = customer.stock_id AND stock_reference_type_id = 1 GROUP BY stock.parent_id

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• Newsletter send using AJAX to avoid PHP timeout

  - by simPod

  I need to send newsletters. I have already a PHP script that sends mass emails but it won't work for long as email database is growing because of PHP max script run time. So, to avoid it I came up with a solution: I would call my PHP script using AJAX in javascript and I will give it $_GET parameter with a count 20 so the script would sent only 20 emails. Than AJAX would receive success response, and call my script again and again till all emails are send. Is it possible? I'm asking because I have never seen such a solution so I'm wondering if it is real (It's kinda hard to implement this into my PHP framework so I'm asking experts here first) To sum it up here's a code skeleton: <script> var emailCount = 1000; //would get this from DB var runCount = 20; //number of emails sent in one cycle var from = 0; //start number function sendMail(){ if(from<emailCount){ jQuery.ajaxfunction({ path: 'script.php?from='+from+'&count='+runCount successFc: function(){ from+=runCount; sendMail(); } }) } } sendMail(); </script> So, are there any obstacles? Thanks a lot.

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• How to join results from two different sets in LINQ?

  - by Inez

  Hi, I get some data about customers in my database with this method: public List<KlientViewModel> GetListOfKlientViewModel() { List<KlientViewModel> list = _klientRepository.List().Select(k => new KlientViewModel { Id = k.Id, Imie = k.Imie, Nazwisko = k.Nazwisko, Nazwa = k.Nazwa, SposobPlatnosci = k.SposobPlatnosci, }).ToList(); return list; } but also I have another method which counts value for extra field in KlientViewModel - field called 'Naleznosci'. I have another method which counts value for this field based on customers ids, it looks like this: public Dictionary<int, decimal> GetNaleznosc(List<int> klientIds) { return klientIds.ToDictionary(klientId => klientId, klientId => (from z in _zdarzenieRepository.List() from c in z.Klient.Cennik where z.TypZdarzenia == (int) TypyZdarzen.Sprzedaz && z.IdTowar == c.IdTowar && z.Sprzedaz.Data >= c.Od && (z.Sprzedaz.Data < c.Do || c.Do == null) && z.Klient.Id == klientId select z.Ilosc*(z.Kwota > 0 ? z.Kwota : c.Cena)).Sum() ?? 0); } So what I want to do is to join data from method GetNaleznosc with data generated in method GetListOfKlientViewModel. I call GetNaleznosc like this: GetNaleznosc(list.Select(k => k.Id).ToList()) but don't know what to do next.

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• php multidimensional array as name value pair

  - by Ayad Mfs

  For ecommerce, that expected name value pair I have the following approved code: function create_example_purchase() { set_credentials(); $purchase = array( 'name' => 'Digital Good Purchase Example', 'description' => 'Example Digital Good Purchase', 'amount' => '12.00', // sum of all item_amount 'items' => array( array( // First item 'item_name' => 'First item name', 'item_description' => 'a description of the 1st item', 'item_amount' => '6.00', 'item_tax' => '0.00', 'item_quantity' => 1, 'item_number' => 'XF100', ), array( // Second item 'item_name' => 'Second Item', 'item_description' => 'a description of the 2nd item', 'item_amount' => '3.00', 'item_tax' => '0.00', 'item_quantity' => 2, 'item_number' => 'XJ100', ), ) ); return new Purchase( $purchase); } I would like to get $items Array inside associative $purchase array dynamically from shipping cart. Is there a way to generate exactly the same output above? My dirty solution, to write $purchase array as string inclusive the generated $items array in a file and include it later in the called script. Help appreciated.

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• Stata Nearest neighbor of percentile

  - by Kyle Billings

  This has probably already been answered, but I must just be searching for the wrong terms. Suppose I am using the built in Stata data set auto: sysuse auto, clear and say for example I am working with 1 independent and 1 dependent variable and I want to essentially compress down to the IQR elements, min, p(25), median, p(75), max... so I use command, keep weight mpg sum weight, detail return list local min=r(min) local lqr=r(p25) local med = r(p50) local uqr = r(p75) local max = r(max) keep if weight==`min' | weight==`max' | weight==`med' | weight==`lqr' | weight==`uqr' Hence, I want to compress the data set down to only those 5 observations, and for example in this situation the median is not actually an element of the weight vector. there is an observation above and an observation below (due to the definition of median this is no surprise). is there a way that I can tell stata to look for the nearest neighbor above the percentile. ie. if r(p50) is not an element of weight then search above that value for the next observation? The end result is I am trying to get the data down to 2 vectors, say weight and mpg such that for each of the 5 elements of weight in the IQR have their matching response in mpg. Any thoughts?

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• Strange Behaviour in Swift: constant defined with LET but behaving like a variable defined with VAR

  - by Sam

  Stuck on the below for a day! Any insight would be greatly appreciated. The constant in the first block match0 behaves as expected. The constant defined in the second block does not behave as nicely in the face of a change to its "source": var str = "+y+z*1.0*sum(A1:A3)" if let range0 = str.rangeOfString("^\\+|^\\-|^\\*|^\\/", options: NSStringCompareOptions.RegularExpressionSearch){ let match0 = str[range0] println(match0) //yields "+" - as expexted str.removeRange(range0) println(match0) //yields "+" - as expected str.removeRange(range0) println(match0) //yields "+" - as expected } if let range1 = str.rangeOfString("^\\+|^\\-|^\\*|^\\/", options: NSStringCompareOptions.RegularExpressionSearch){ let match1 = str[range1] println(match1) //yields "+" as expected str.removeRange(range1) println(match1) //!@#$ OMG!!!!!!!!!!! a constant variable has changed! This prints "z" } The following are the options I can see: match1 has somehow obtained a reference to its source instead of being copied by value [Problem: Strings are value types in Swift] match1 has somehow obtained a closure to its source instead of just being a normal constant/variable? [Problem: sounds like science fiction & then why does match0 behave so well?] Could there be a bug in the Swift compiler? [Problem: Experience has taught me that this is very very very rarely the solution to your problem...but it is still in beta]

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• convert list of relative widths to pixel widths

  - by mkoryak

  This is a code review question more then anything. I have the following problem: Given a list of relative widths (no unit whatsoever, just all relative to each other), generate a list of pixel widths so that these pixel widths have the same proportions as the original list. input: list of proportions, total pixel width. output: list of pixel widths, where each width is an int, and the sum of these equals the total width. Code: var sizes = "1,2,3,5,7,10".split(","); //initial proportions var totalWidth = 1024; // total pixel width var sizesTotal = 0; for (var i = 0; i < sizes.length; i++) { sizesTotal += parseInt(sizes[i], 10); } if(sizesTotal != 100){ var totalLeft = 100;; for (var i = 0; i < sizes.length; i++) { sizes[i] = Math.floor(parseInt(sizes[i], 10) / sizesTotal * 100); totalLeft -= sizes[i]; } sizes[sizes.lengh - 1] = totalLeft; } totalLeft = totalWidth; for (var i = 0; i < sizes.length; i++) { widths[i] = Math.floor(totalWidth / 100 * sizes[i]) totalLeft -= widths[i]; } widths[sizes.lenght - 1] = totalLeft; //return widths which contains a list of INT pixel sizes

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• Counting problem C#

  - by MadBoy

  Hello, I've a bit of a problem. I'm adding numbers to ArrayList like 156, 340 (when it is TransferIn or Buy) etc and then i remove them doing it like 156, 340 (when it's TransferOut, Sell). Following solution works for that without a problem. The problem I have is that for some old data employees were entering sum's like 1500 instead of 500+400+100+500. How would I change it so that when there's Sell/TransferOut and there's no match inside ArrayList it should try to add multiple items from that ArrayList and find elements that combine into aggregate. ArrayList alNew = new ArrayList(); ArrayList alNewPoIle = new ArrayList(); ArrayList alNewCo = new ArrayList(); string tempAkcjeCzynnosc = (string) alInstrumentCzynnoscBezNumerow[i]; string tempAkcjeInId = (string) alInstrumentNazwaBezNumerow[i]; decimal varAkcjeCena = (decimal) alInstrumentCenaBezNumerow[i]; decimal varAkcjeIlosc = (decimal) alInstrumentIloscBezNumerow[i]; int index; switch (tempAkcjeCzynnosc) { case "Sell": case "TransferOut": index = alNew.IndexOf(varAkcjeIlosc); if (index != -1) { alNew.RemoveAt(index); alNewPoIle.RemoveAt(index); alNewCo.RemoveAt(index); } else { // Number without match encountred } break; case "Buy": case "TransferIn": alNew.Add(varAkcjeIlosc); alNewPoIle.Add(varAkcjeCena); alNewCo.Add(tempAkcjeInId); break; } }

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• Mysql - Operand should contain 1 column(s) : What's wrong with the query...?

  - by SpikETidE

  Hi everybody.... I am trying to query a database to find the following If a customer searches for a hotel in a city between dates A and B, find and return the hotels in which rooms are free between the two dates. There will be more than one room in each room type(i.e. 5 Rooms in type A, 10 rooms in Type B etc) and we have to query the db to find only those hotels in which there is atleast one room free in atleast one type. This is my table structure.... **Structure for table 'reservations'** reservation_id hotel_id room_id customer_id payment_id no_of_rooms check_in_date check_out_date reservation_date **Structure for table 'hotels'** hotel_id hotel_name hotel_description hotel_address hotel_location hotel_country hotel_city hotel_type hotel_stars hotel_image hotel_deleted **Structure for table 'rooms'** room_id hotel_id room_name max_persons total_rooms room_price room_image agent_commision room_facilities service_tax vat city_tax room_description room_deleted And this is my query $city_search = '15'; $check_in_date = '29-03-2010'; $check_out_date = '31-03-2010'; $dateFormat_check_in = "DATE_FORMAT('$reservations.check_in_date','%d-%m-%Y')"; $dateFormat_check_out = "DATE_FORMAT('$reservations.check_out_date','%d-%m-%Y')"; $dateCheck = "$dateFormat_check_in >= '$check_in_date' AND $dateFormat_check_out <= '$check_out_date'"; $query = "SELECT $rooms.room_id, $rooms.room_name, $rooms.max_persons, $rooms.room_price, $hotels.hotel_id, $hotels.hotel_name, $hotels.hotel_stars, $hotels.hotel_type FROM $hotels,$rooms,$reservations WHERE $hotels.hotel_city = '$city_search' AND $hotels.hotel_id = $rooms.hotel_id AND $hotels.hotel_deleted = '0' AND $rooms.room_deleted = '0' AND $rooms.total_rooms - (SELECT SUM($reservations.no_of_rooms) as tot, $rooms.room_id as id FROM $reservations,$rooms WHERE $dateCheck GROUP BY $reservations.room_id) > '0'"; The number of rooms already reserved in each room type in each hotel will be stored in the reservations table... The query returns the error : Operand should contain 1 column(s) I tried running the sub-query alone but i don't get any result... And i have lost quite some amount of hair trying to de-bug this query from yesterday... What's wrong with this...? Or is there a better way to do what i mentioned above...? Thanks for your time...

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• Jquery Bugs?? Long decimal number after two numbers multiply...

  - by Jerry

  Hi all I am working on a shopping site and I am trying to calculate the subtotal of products. I got my price from a array and quantity from getJSON response array. Two of them multiply comes to my subtotal. I can change the quantity and it will comes out different subtotal. However,when I change the quantity to certain number, the final subtotal is like 259.99999999994 or some long decimal number. I use console.log to check the $price and $qty. Both of them are in the correct format ex..299.99 and 6 quantity.I have no idea what happen. I would appreciate it if someone can help me about it. Here is my Jquery code. $(".price").each(function(index, price){ $price=$(this); //get the product id and the price shown on the page var id=$price.closest('tr').attr('id'); var indiPrice=$($price).html(); //take off $ indiPrice=indiPrice.substring(1) //make sure it is number format var aindiPrice=Number(indiPrice); //push into the array productIdPrice[id]=(aindiPrice); var url=update.php $.getJSON( url, {productId:tableId, //tableId is from the other jquery code which refers to qty:qty}, productId function(responseProduct){ $.each(responseProduct, function(productIndex, Qty){ //loop the return data if(productIdPrice[productIndex]){ //get the price from the previous array we create X Qty newSub=productIdPrice[productIndex]*Number(Qty); //productIdPrice[productIndex] are the price like 199.99 or 99.99 // Qty are Quantity like 9 or 10 or 3 sum+=newSub; newSub.toFixed(2); //try to solve the problem with toFixed but didn't work console.log("id: "+productIdPrice[productIndex]) console.log("Qty: "+Qty); console.log(newSub); **//newSub sometime become XXXX.96999999994** }; Thanks again!

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• Which database I can used and relationship in it ??

  - by mimo-hamad

  My projece make me confused which I didn't find clear things that make me understand the required database and the relationships in it So, would a super one help me to solve it ?!! ;D this is required: 1) Model the data stored in the database (Identify the entities, roles, relationships, constraints, etc.) 2) Write the Oracle commands to create the database, find appropriate data, and populate the database 3) Write five different queries on your database, using the SELECT/FROM/WHERE construct provided in SQL. Your five queries should illustrate several different aspects of database querying, such as: a. Queries over more than one relation (by listing more than one relation in the FROM clause) b. Queries involving aggregate functions, such as SUM, COUNT, and AVG c. Queries involving complicated selects and joins d. Queries involving GROUP BY, HAVING or other similar functions. e. Queries that require the use of the DISTINCT keyword. And this the condition that we need to determine it to solve the required Q's above : 5) It is desired to develop an Internet membership club to buy products at special prices online. To join, new members must be referred by another existing member of the club. The system will keep the following information for each member: The member ID, referring member, birth date, member name, address, phone, mobile, credit card type, number and expiration date. The items are always shipped to the member's address noted in the membership application. The shipping fees will differ for each order.For each item to be requested, the member will select an item from a long list of possible items. For each item in the database, we store an item ID, an item name, description, and list price. The list price will be different from the actual sale price. The available quantity and the back-ordered quantity (the back-ordered quantity is the quantity on-order by the club from its suppliers) is also noted

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• Oracle SQL: ROLLUP not summing correctly

  - by tommy-o-dell

  Hi guys, Rollup seems to be working correcly to count the number of units, but not the number of trains. Any idea what could be causing that? The output from the query looks like this. The sum of the Units column in yellow is 53 but the rollup is showing 51. The number of units adds up correctly though... And here's the oracle SQL query... select t.year, t.week, decode(t.mine_id,NULL,'PF',t.mine_id) as mine_id, decode(t.product,Null,'LF',t.product) as product, decode(t.mine_id||'-'||t.product,'-','PF',t.mine_id||'-'||t.product) as code, count(distinct t.tpps_train_id) as trains, count(1) as units from ( select trn.mine_code as mine_id, trn.train_tpps_id as tpps_train_id, round((con.calibrated_weight_total - con.empty_weight_total),2) as tonnes from widsys.train trn INNER JOIN widsys.consist con USING (train_record_id) where trn.direction = 'N' and (con.calibrated_weight_total-con.empty_weight_total) > 10 and trn.num_cars > 10 and con.consist_no not like '_L%' ) w, ( select to_char(td.datetime_act_comp_dump-7/24, 'IYYY') as year, to_char(td.datetime_act_comp_dump-7/24, 'IW') as week, td.mine_code as mine_id, td.train_id as tpps_train_id, pt.product_type_code as product from tpps.train_details td inner join tpps.ore_products op using (ore_product_key) inner join tpps.product_types pt using (product_type_key) where to_char(td.datetime_act_comp_dump-7/24, 'IYYY') = 2010 and to_char(td.datetime_act_comp_dump-7/24, 'IW') = 12 order by td.datetime_act_comp_dump asc ) t where w.mine_id = t.mine_id and w.tpps_train_id = t.tpps_train_id having t.product is not null or t.mine_id is null group by t.year, t.week, rollup( t.mine_id, t.product)

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• OpenCL - incremental summation during compute

  - by user1721997

  I'm absolutelly novice in OpenCL programming. For my app. (molecular simulaton) I wrote a kernel for calculate intermolecular potential of lennard-jones liquid. In this kernel I need to compute cumulative value of the potential of all particles with one: __kernel void Molsim(__global const float* inmatrix, __global float* fi, const int c, const float r1, const float r2, const float r3, const float rc, const float epsilon, const float sigma, const float h1, const float h23) { float fi0; float fi1; float d; unsigned int i = get_global_id(0); //number of particles (typically 2000) if(c!=i) { // potential before particle movement d=sqrt(pow((0.5*h1-fabs(0.5*h1-fabs(inmatrix[c*3]-inmatrix[i*3]))),2.0)+pow((0.5*h23-fabs(0.5*h23-fabs(inmatrix[c*3+1]-inmatrix[i*3+1]))),2.0)+pow((0.5*h23-fabs(0.5*h23-fabs(inmatrix[c*3+2]-inmatrix[i*3+2]))),2.0)); if(d<rc) { fi0=4.0*epsilon*(pow(sigma/d,12.0)-pow(sigma/d,6.0)); } else { fi0=0; } // potential after particle movement d=sqrt(pow((0.5*h1-fabs(0.5*h1-fabs(r1-inmatrix[i*3]))),2.0)+pow((0.5*h23-fabs(0.5*h23-fabs(r2-inmatrix[i*3+1]))),2.0)+pow((0.5*h23-fabs(0.5*h23-fabs(r3-inmatrix[i*3+2]))),2.0)); if(d<rc) { fi1=4.0*epsilon*(pow(sigma/d,12.0)-pow(sigma/d,6.0)); } else { fi1=0; } // cumulative difference of potentials fi[0]+=fi1-fi0; } } My problem is in the line: fi[0]+=fi1-fi0;. In the one-element vector fi[0] are wrong results. I read something about sum reduction, but I do not know how to do it during the calculation. Exist any simple solution of my problem?

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• Project management and bundling dependencies

  - by Joshua

  I've been looking for ways to learn about the right way to manage a software project, and I've stumbled upon the following blog post. I've learned some of the things mentioned the hard way, others make sense, and yet others are still unclear to me. To sum up, the author lists a bunch of features of a project and how much those features contribute to a project's 'suckiness' for a lack of a better term. You can find the full article here: http://spot.livejournal.com/308370.html In particular, I don't understand the author's stance on bundling dependencies with your project. These are: == Bundling == Your source only comes with other code projects that it depends on [ +20 points of FAIL ] Why is this a problem, (especially given the last point)? If your source code cannot be built without first building the bundled code bits [ +10 points of FAIL ] Doesn't this necessarily have to be the case for software built against 3rd party libs? Your code needs that other code to be compiled into its library before the linker can work? If you have modified those other bundled code bits [ +40 points of FAIL ] If this is necessary for your project, then it naturally follows that you've bundled said code with yours. If you want to customize a build of some lib,say WxWidgets, you'll have to edit that projects build scripts to bulid the library that you want. Subsequently, you'll have to publish those changes to people who wish to build your code, so why not use a high level make script with the params already written in, and distribute that? Furthermore, (especially in a windows env) if your code base is dependent on a particular version of a lib (that you also need to custom compile for your project) wouldn't it be easier to give the user the code yourself (because in this case, it is unlikely that the user will already have the correct version installed)? So how would you respond to these comments, and what points may I be failing to take into consideration? Would you agree or disagree with the author's take (or mine), and why?

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• How to benchmark on multi-core processors

  - by Pascal Cuoq

  I am looking for ways to perform micro-benchmarks on multi-core processors. Context: At about the same time desktop processors introduced out-of-order execution that made performance hard to predict, they, perhaps not coincidentally, also introduced special instructions to get very precise timings. Example of these instructions are rdtsc on x86 and rftb on PowerPC. These instructions gave timings that were more precise than could ever be allowed by a system call, allowed programmers to micro-benchmark their hearts out, for better or for worse. On a yet more modern processor with several cores, some of which sleep some of the time, the counters are not synchronized between cores. We are told that rdtsc is no longer safe to use for benchmarking, but I must have been dozing off when we were explained the alternative solutions. Question: Some systems may save and restore the performance counter and provide an API call to read the proper sum. If you know what this call is for any operating system, please let us know in an answer. Some systems may allow to turn off cores, leaving only one running. I know Mac OS X Leopard does when the right Preference Pane is installed from the Developers Tools. Do you think that this make rdtsc safe to use again? More context: Please assume I know what I am doing when trying to do a micro-benchmark. If you are of the opinion that if an optimization's gains cannot be measured by timing the whole application, it's not worth optimizing, I agree with you, but I cannot time the whole application until the alternative data structure is finished, which will take a long time. In fact, if the micro-benchmark were not promising, I could decide to give up on the implementation now; I need figures to provide in a publication whose deadline I have no control over.

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• How do I use price data in one table for a calculation that is stored in another table?

  - by shane

  I'm still leanring PHP/MySQL but have learned quite a bit thanks to codies on StackOverflow. I'm trying to setup a sort of room reservations system using two tables: SETUP: Room price table: Has, prices for a type room a client may want to rent as well as the dates (day of week) they wish to use it. Pricing varies based on day of the week and per room. I've setup a different table for each room type as each room type carries different pricing for each day of the week. So, There is an Alpha room table, Bravo room, etc. Within Alpha table are headers for the days of the week with pricing pre-entered into the rows. Client info table: Has the name, address, date of room use, etc data for the specific client. EXAMPLE: Alpha-room price table: Sun = $100; Mon = $200; Tue=$300 and so on. Bravo-room price table: Sun = $100; Mon = $200; Tue=$300 and so on. Client data table: ClientName; date-of-room-use; address; day_subtotal; grand_total. QUESTION: I'm trying to find PHP code that will: look at the date of room use in the client data table, look up the associated cost for that date in the specific room pricing table, record that unit cost in the day subtotal of the client data table and sum a grand total in the grand total row of the client data table (assuming the room may be used more than one day by the customer). I know there's something to do with join but I'm finding it difficult to grasp the concept and, if someone can demonstrate using this example, I think I will have a better understanding of how to work this sort of transaction. Thank you ALL in advance for your suggestions or alternatvie approaches.

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• Error in Python's os.walk?

  - by Mike Caron

  The os.walk documentation (http://docs.python.org/library/os.html? highlight=os.walk#os.walk), says I can skip traversing unwanted directories by removing them from the dir list. The explicit example from the docs: import os from os.path import join, getsize for root, dirs, files in os.walk('python/Lib/email'): print root, "consumes", print sum(getsize(join(root, name)) for name in files), print "bytes in", len(files), "non-directory files" if 'CVS' in dirs: dirs.remove('CVS') # don't visit CVS directories I see different behavior (using ActivePython 2.6.2). Namely for the code: >>> for root,dirs,files in os.walk(baseline): ... if root.endswith(baseline): ... for d in dirs: ... print "DIR: %s" % d ... if not d.startswith("keep_"): ... print "Removing %s\\%s" % (root,d) ... dirs.remove(d) ... ... print "ROOT: %s" % root ... I get the output: DIR: two Removing: two DIR: thr33 Removing: thr33 DIR: keep_me DIR: keep_me_too DIR: keep_all_of_us ROOT: \\mach\dirs ROOT: \\mach\dirs\ONE ROOT: \\mach\dirs\ONE\FurtherRubbish ROOT: \\mach\dirs\ONE\FurtherRubbish\blah ROOT: \\mach\dirs\ONE\FurtherRubbish\blah\Extracted ROOT: \\mach\dirs\ONE\FurtherRubbish\blah2\Extracted\Stuff_1 ... WTF? Why wasn't \\mach\dirs\ONE removed? It clearly doesn't start with "keep_".

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• smartgwt operationId not working

  - by dubreakkk

  Hello all: How do operationIds work when calling a smartGWT fetch operation? I have the following simple Datasource, and below it the code that calls that datasource. However, the operationId is never acknowledged, and the first fetch operation is always executed... <DataSource ID="cartDS" serverType="sql" tableName="cart"> <fields> <field name="cart_id" type="number"/> <field name="price" type="double"/> <field name="total" type="double" customSQL="true"/> </fields> <dbName></dbName> <operationBindings> <operationBinding operationType="fetch"> <values fieldName="cart_id" value="$session.id"/> </operationBinding> <operationBinding operationType="fetch" operationId="total"> <values fieldName="cart_id" value="$session.id"/> <selectClause>sum(price) AS total </selectClause> </operationBinding> final DynamicForm totalForm = new DynamicForm(); totalForm.setDataSource(cartDS); totalForm.setFetchOperation("total"); totalForm.fetchData();

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• Optimizing an embedded SELECT query in mySQL

  - by Crazy Serb

  Ok, here's a query that I am running right now on a table that has 45,000 records and is 65MB in size... and is just about to get bigger and bigger (so I gotta think of the future performance as well here): SELECT count(payment_id) as signup_count, sum(amount) as signup_amount FROM payments p WHERE tm_completed BETWEEN '2009-05-01' AND '2009-05-30' AND completed > 0 AND tm_completed IS NOT NULL AND member_id NOT IN (SELECT p2.member_id FROM payments p2 WHERE p2.completed=1 AND p2.tm_completed < '2009-05-01' AND p2.tm_completed IS NOT NULL GROUP BY p2.member_id) And as you might or might not imagine - it chokes the mysql server to a standstill... What it does is - it simply pulls the number of new users who signed up, have at least one "completed" payment, tm_completed is not empty (as it is only populated for completed payments), and (the embedded Select) that member has never had a "completed" payment before - meaning he's a new member (just because the system does rebills and whatnot, and this is the only way to sort of differentiate between an existing member who just got rebilled and a new member who got billed for the first time). Now, is there any possible way to optimize this query to use less resources or something, and to stop taking my mysql resources down on their knees...? Am I missing any info to clarify this any further? Let me know... EDIT: Here are the indexes already on that table: PRIMARY PRIMARY 46757 payment_id member_id INDEX 23378 member_id payer_id INDEX 11689 payer_id coupon_id INDEX 1 coupon_id tm_added INDEX 46757 tm_added, product_id tm_completed INDEX 46757 tm_completed, product_id

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• Get count of rows in each table while having more than 1 tables

  - by sneha khan

  I have more then one tables on same page and want to add a line show count of each table as below. I tried something but it gives sum of count of all table rows. <table> <tr> <td>Some data</td> <td>More data</td> </tr> <tr> <td>Some data</td> <td>More data</td> </tr> </table> <table> <tr> <td>Some data</td> <td>More data</td> </tr> <tr> <td>Some data</td> <td>More data</td> </tr> </table> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript"> $().ready(function(){ //I want to add a line after each table showing each table row count $("table").after(??? + " rows found."); }); </script>

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• function taking in an input image and different kernel size

  - by drifterOcean19

  I have this filtering function that takes an input image, performs convolution using a given kernel, and returns the resulting image. However, I can't seem to work it out how to make it takes different kernel sizes.For example instead of pre-defined 3x3 kernel as below in the code, it could instead take 5x5 or 7x7. and then the user could input the type of kernel/filter they want(Depending on the intended effect). I can't seem to put my head around it. i'm quite new to matlab. function [newImg] = kernelFunc(imgB) img=imread(imgB); figure,imshow(img); img2=zeros(size(img)+2); newImg=zeros(size(img)); for rgb=1:3 for x=1:size(img,1) for y=1:size(img,2) img2(x+1,y+1,rgb)=img(x,y,rgb); end end end for rgb=1:3 for i= 1:size(img2,1)-2 for j=1:size(img2,2)-2 window=zeros(9,1); inc=1; for x=1:3 for y=1:3 window(inc)=img2(i+x-1,j+y-1,rgb); inc=inc+1; end end kernel=[1;2;1;2;4;2;1;2;1]/16; med=window.*kernel; disp(med); med=sum(med); med=floor(med); newImg(i,j,rgb)=med; end end end newImg=uint8(newImg); figure,imshow(newImg); end

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