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  • WPF Exposing a calculated property for binding (as DependencyProperty)

    - by kubal5003
    Hello, I have a complex WPF control that for some reasons (ie. performance) is not using dependency properties but simple C# properties (at least at the top level these are exposed as properties). The goal is to make it possible to bind to some of those top level properties - I guess I should declare them as DPs.(right? or is there some other way to achieve this? ) I started reading on MSDN about DependencyProperties and DependencyObjects and found an example: public class MyStateControl : ButtonBase { public MyStateControl() : base() { } public Boolean State { get { return (Boolean)this.GetValue(StateProperty); } set { this.SetValue(StateProperty, value); } } public static readonly DependencyProperty StateProperty = DependencyProperty.Register( "State", typeof(Boolean), typeof(MyStateControl),new PropertyMetadata(false)); } If I'm right - this code enforces the property to be backed up by DependencyProperty which restricts it to be a simple property with a store(from functional point of view, not technically) instead of being able to calculate the property value each time getter is called and setting other properties/fields each time setter is called. What can I do about that? Is there any way I could make those two worlds meet at some point?

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  • Jquery and XML - How to add the value of nodes

    - by Matias
    Hi Experts, This may be a simple question though can´t figure out how to do it. I am parsing an XML with Jquery Ajax. It contains dates and rates The XML looks something like <rate> <date>Today</date> <price>66</price> </rate> <rate> <date>Tomorrow</date> <price>99</price> </rate> I simply want to figure out how to calculate the total price of both days Today and Tomorrow. Thought that by using Javascript Number it will simply return the total value of the nodes.. $(xml).find("rate").each(function() { $(this).find("price").each(function() { $("#TOTALPRICE").append(Number($(this).text())); } } //output is: 6699 However, it´s just concatenating the values both not adding them. //output is: 6699 I greatly appreciate your help !! Thanks

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  • How to resize image to fit UITableView cell?

    - by stefanB
    How to fit UIImage into the cell of UITableView, UITableViewCell (?). Do you addSubview to cell or is there a way to resize cell.image or the UIImage before it is assigned to cell.image ? I want to keep the cell size default (whatever it is when you init with zero rectangle) and would like to add icon like pictures to each entry. Images are slightly bigger than the cell size (table row size). I think the code looks like this (from top of my head): UIImage * image = [[UIImage alloc] imageWithName:@"bart.jpg"]; cell = ... dequeue cell in UITableView data source (UITableViewController ...) cell.text = @"bart"; cell.image = image; What do I need to do to resize the image to fit the cell size? I've seen something like: UIImageView * iview = [[UIImageView alloc] initWithImage:image]; iview.frame = CGRectMake(...); // or something similar [cell.contentView addSubview:iview] The above will add image to cell and I can calculate the size to fit it, however: I'm not sure if there is a better way, isn't it too much overhead to add UIImageView just to resize the cell.image ? Now my label (cell.text) needs to be moved as it is obscured by image, I've seen a solution where you just add the text as a label: Example: UILabel * text = [[UILable alloc] init]; text.text = @"bart"; [cell.contentView addSubview:iview]; [cell.contentView addSubview:label]; // not sure if this will position the text next to the label // edited original example had [cell addSubview:label], maybe that's the problem Could someone point me in correct direction? EDIT: Doh [cell.contentview addSubview:view] not [cell addSubview:view] maybe I'm supposed to look at this: - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { UITableViewCell *cell = ...; CGRect frame = cell.contentView.bounds; UILabel *myLabel = [[UILabel alloc] initWithFrame:frame]; myLabel.text = ...; [cell.contentView addSubview:myLabel]; [myLabel release]; }

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  • gnuplot: display only the roots.

    Hi, Gnuplot, a great package ... I'm in love with it. But we can have our tiffs as well, as any couple :-) This time, I wanted to simply plot the roots of an equation: say a quadratic to keep things simple. However, I only want two nice round dots appearing on the x-axis representing the point where the quadratic crosses the x-axis or y=0 axis. In other words the roots (when they are real that is). I don't want to do this with datafile ... I want gnuplot to calculate the roots and plot them. First off, my attempts: single points aren't really what gnuplot would have you plot, it likes a good wide range of values. Preferably filling up the whole width of your canvas. It's possible to locate a rectangle at a certain coordinate on your plot, but I wanted a round point. Currently I'm chasing up how to do a tiny filled polygon at that point. I have tried the "samples" option bu it doesn't seem useful. Also though about defining a dirac-delta function so that only one point would be highlighted (though two would be needed). ANy suggestions welcome, thanks.

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  • how to show avg of employees salary in a NSTextField using NSArrayController and cocoa bindings

    - by Miraaj
    Hi all, I am new to cocoa bindings so I tried to make a simple application which will simply calculate avg of employees salary and display it in a text field, using cocoa bindings. I followed these steps: Made the model class : Person with one property for now - @property (readwrite, assign) int salary; In the application delegate class I initialized a mutable array : personArray with certain objects like this: Person *person1 = [[Person alloc] init]; person1.salary = 5000; Person *person2 = [[Person alloc] init]; person2.salary = 15000; Person *person3 = [[Person alloc] init]; person3.salary = 7000; Person *person4 = [[Person alloc] init]; person4.salary = 9000; Person *person5 = [[Person alloc] init]; person5.salary = 11000; personArray= [[NSMutableArray alloc] initWithObjects:person1, person2, person3, person4, person5,nil]; In IB I dropped a NSArrayController object, set its mode as Class - Person, added key salary in attribute pane. Then in bindings pane, binded contents array to ApplicationDelegate class with model key path set to self.personArray. Dropped a NSTextField on window. Binded its value to ArrayController object. Assigned controller key as - arrangedObjects. Assigned Model key path to @avg.salary When I executed the application I found no value being displayed in the text field. Can anyone suggest me where I may be wrong? Thanks, Miraaj

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  • Wpf progressbar not updating during method calculation

    - by djerry
    Hey guys, In my app, i have an import option, to read info from a .csv or .txt file and write it to a database. To test, i"m just using 200-300 lines of data. At the beginning of the method, i calculate number of objects/lines to be read. Every time an object is written to the database, i want to update my progressbar. This is how i do it : private void Update(string path) { double lines = 0; using (StreamReader reader = new StreamReader(path)) while ((reader.ReadLine()) != null) lines++; if (lines != 0) { double progress = 0; string lijn; double value = 0; List<User> users = new List<User>(); using (StreamReader reader = new StreamReader(path)) while ((line = reader.ReadLine()) != null) { progress++; value = (progress / lines) * 100.0; updateProgressBar(value); try { User user = ProcessLine(lijn); } catch (ArgumentOutOfRangeException) { continue; } catch (Exception) { continue; } } return; } else { //non relevant code } } To update my progressbar, i'm checking if i can change the ui of the progressbar like this : delegate void updateProgressbarCallback(double value); private void updateProgressBar(double value) { if (pgbImportExport.Dispatcher.CheckAccess() == false) { updateProgressbarCallback uCallBack = new updateProgressbarCallback(updateProgressBar); pgbImportExport.Dispatcher.Invoke(uCallBack, value); } else { Console.WriteLine(value); pgbImportExport.Value = value; } } When i!m looking at the output, the values are calculated correctly, but the progressbar is only showing changes after the method has been called completely, so when the job is done. That's too late to show feedback to the user. Can anyone help me solve this. EDIT : I'm also trying to show some text in labels to tell te user what is being done, and those aren't udpated till after the method is complete. Thanks in advance.

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  • Create ntp time stamp from gettimeofday

    - by krunk
    I need to calculate an ntp time stamp using gettimeofday. Below is how I've done it with comments on method. Look good to you guys? (minus error checking). Also, here's a codepad link. #include <unistd.h> #include <sys/time.h> const unsigned long EPOCH = 2208988800UL; // delta between epoch time and ntp time const double NTP_SCALE_FRAC = 4294967295.0; // maximum value of the ntp fractional part int main() { struct timeval tv; uint64_t ntp_time; uint64_t tv_ntp; double tv_usecs; gettimeofday(&tv, NULL); tv_ntp = tv.tv_sec + EPOCH; // convert tv_usec to a fraction of a second // next, we multiply this fraction times the NTP_SCALE_FRAC, which represents // the maximum value of the fraction until it rolls over to one. Thus, // .05 seconds is represented in NTP as (.05 * NTP_SCALE_FRAC) tv_usecs = (tv.tv_usec * 1e-6) * NTP_SCALE_FRAC; // next we take the tv_ntp seconds value and shift it 32 bits to the left. This puts the // seconds in the proper location for NTP time stamps. I recognize this method has an // overflow hazard if used after around the year 2106 // Next we do a bitwise AND with the tv_usecs cast as a uin32_t, dropping the fractional // part ntp_time = ((tv_ntp << 32) & (uint32_t)tv_usecs); }

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  • function getting wrong values

    - by frankie
    so i have this function in C to calculate a power, and i'm using visual c++ 2010 power.h void power(); float get_power(float a, int n); power.c void power() { float a, r; int n; printf("-POWER-\n"); printf("The base: "); scanf("%f", &a); n = -1; while (n < 0) { printf("The power: "); scanf("%d", &n); if (n < 0) { printf("Power must be equal or larger than 0!\n"); } else { r = get_power(a, n); printf("%.2f ^ %d = %.2f", a, n, r); } }; } float get_power(float a, int n) { if (n == 0) { return 1; } return a * get_power(a, n-1); } not the best way to do it, i know, but that's not it when i debug it the values are scanned correctly (that is, the values are correct until just before the function call) but then upon entering the function a becomes 0 and n becomes 1074790400, and you can guess what happens next... the first function is being called from the main file, i included the full code because i really have no idea what could be going on, and i can't even think on how to google for it... strangely, i wrote the function in a single file and it works fine, but it definitely should work both ways any idea why this is happening?

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  • Project Euler Question 14 (Collatz Problem)

    - by paradox
    The following iterative sequence is defined for the set of positive integers: n -n/2 (n is even) n -3n + 1 (n is odd) Using the rule above and starting with 13, we generate the following sequence: 13 40 20 10 5 16 8 4 2 1 It can be seen that this sequence (starting at 13 and finishing at 1) contains 10 terms. Although it has not been proved yet (Collatz Problem), it is thought that all starting numbers finish at 1. Which starting number, under one million, produces the longest chain? NOTE: Once the chain starts the terms are allowed to go above one million. I tried coding a solution to this in C using the bruteforce method. However, it seems that my program stalls when trying to calculate 113383. Please advise :) #include <stdio.h> #define LIMIT 1000000 int iteration(int value) { if(value%2==0) return (value/2); else return (3*value+1); } int count_iterations(int value) { int count=1; //printf("%d\n", value); while(value!=1) { value=iteration(value); //printf("%d\n", value); count++; } return count; } int main() { int iteration_count=0, max=0; int i,count; for (i=1; i<LIMIT; i++) { printf("Current iteration : %d\n", i); iteration_count=count_iterations(i); if (iteration_count>max) { max=iteration_count; count=i; } } //iteration_count=count_iterations(113383); printf("Count = %d\ni = %d\n",max,count); }

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  • Storing statistics of multple data types in SQL Server 2008

    - by Mike
    I am creating a statistics module in SQL Server 2008 that allows users to save data in any number of formats (date, int, decimal, percent, etc...). Currently I am using a single table to store these values as type varchar, with an extra field to denote the datatype that it should be. When I display the value, I use that datatype field to format it. I use sprocs to calculate the data for reporting; and the datatype field to convert to the appropriate datatype for the appropriate calculations. This approach works, but I don't like storing all kinds of data in a varchar field. The only alternative that I can see is to have separate tables for each datatype I want to store, and save the record information to the appropriate table based on datatype. To retreive, I run a case statement to join the appropriate table and get the data. This seems to solve. This however, seems like a lot of work for ... what gain? Wondering if I'm missing something here. Is there a better way to do this? Thanks in advance!

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  • MDX equivalent to SQL subqueries with aggregation

    - by James Lampe
    I'm new to MDX and trying to solve the following problem. Investigated calculated members, subselects, scope statements, etc but can't quite get it to do what I want. Let's say I'm trying to come up with the MDX equivalent to the following SQL query: SELECT SUM(netMarketValue) net, SUM(CASE WHEN netMarketValue > 0 THEN netMarketValue ELSE 0 END) assets, SUM(CASE WHEN netMarketValue < 0 THEN netMarketValue ELSE 0 END) liabilities, SUM(ABS(netMarketValue)) gross someEntity1 FROM ( SELECT SUM(marketValue) netMarketValue, someEntity1, someEntity2 FROM <some set of tables> GROUP BY someEntity1, someEntity2) t GROUP BY someEntity1 In other words, I have an account ledger where I hide internal offsetting transactions (within someEntity2), then calculate assets & liabilities after aggregating them by someEntity2. Then I want to see the grand total of those assets & liabilities aggregated by the bigger entity, someEntity1. In my MDX schema I'd presumably have a cube with dimensions for someEntity1 & someEntity2, and marketValue would be my fact table/measure. I suppose i could create another DSV that did what my subquery does (calculating net), and simply create a cube with that as my measure dimension, but I wonder if there is a better way. I'd rather not have 2 cubes (one for these net calculations and another to go to a lower level of granularity for other use cases), since it will be a lot of duplicate info in my database. These will be very large cubes.

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  • Highlighting a Table Correctly Despite rowspan and colspan attributes - WITHOUT jQuery

    - by ScottSEA
    Thanks to some !#$#@ in another department who wrote some crap code, I am unable to use the jQuery library - despite my fervent desire to do so. Their software has already been released into the world, and I have to be compatible. ============================================ I am trying to highlight a table. Desired behavior: Clicking on a cell in the body highlights the row. Clicking on a cell in the head highlights the column. If a column and row are both highlighted, the intersection is highlighted a different color (super-highlight). Clicking on a previously super-highlighted cell turns off the highlights. This behavior is simple enough to do with a basic table, but when rowspans and colspans start rearing their ugly heads, things start to get a little wonky... highlighting cell[5], for instance, no longer works reliably. My thought, in order to speed execution time of the highlighting itself (by changing a class name), is to pre-calculate the 'offsets' of all cells - with a 'colStart' and 'colEnd', 'rowStart' and 'rowEnd' when the page loads and store that in an array somehow. The question: How would YOU implement this functionality? I am fairly rusty at my JavaScript, awfully rudimentary in my programming skills and would benefit greatly from some guidance. Thanks, Scott.

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  • Annotate over Multi-table Inheritance in Django

    - by user341584
    I have a base LoggedEvent model and a number of subclass models like follows: class LoggedEvent(models.Model): user = models.ForeignKey(User, blank=True, null=True) timestamp = models.DateTimeField(auto_now_add=True) class AuthEvent(LoggedEvent): good = models.BooleanField() username = models.CharField(max_length=12) class LDAPSearchEvent(LoggedEvent): type = models.CharField(max_length=12) query = models.CharField(max_length=24) class PRISearchEvent(LoggedEvent): type = models.CharField(max_length=12) query = models.CharField(max_length=24) Users generate these events as they do the related actions. I am attempting to generate a usage-report of how many of each event-type each user has caused in the last month. I am struggling with Django's ORM and while I am close I am running into a problem. Here is the query code: ef usage(request): # Calculate date range today = datetime.date.today() month_start = datetime.date(year=today.year, month=today.month - 1, day=1) month_end = datetime.date(year=today.year, month=today.month, day=1) - datetime.timedelta(days=1) # Search for how many LDAP events were generated per user, last month baseusage = User.objects.filter(loggedevent__timestamp__gte=month_start, loggedevent__timestamp__lte=month_end) ldapusage = baseusage.exclude(loggedevent__ldapsearchevent__id__lt=1).annotate(count=Count('loggedevent__pk')) authusage = baseusage.exclude(loggedevent__authevent__id__lt=1).annotate(count=Count('loggedevent__pk')) return render_to_response('usage.html', { 'ldapusage' : ldapusage, 'authusage' : authusage, }, context_instance=RequestContext(request)) Both ldapusage and authusage are both a list of users, each user annotated with a .count attribute which is supposed to represent how many particular events that user generated. However in both lists, the .count attributes are the same value. Infact the annotated 'count' is equal to how many events that user generated, regardless of type. So it would seem that my specific authusage = baseusage.exclude(loggedevent__authevent__id__lt=1) isn't excluding by subclass. I have tried id_lt=1, id_isnull=True, and others. Halp.

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  • Fuzzy Date algorithm in Objective-C

    - by Brock Woolf
    I would like to write a fuzzy date method for calculating dates in Objective-C for iPhone. There is a popular explanation here: http://stackoverflow.com/questions/11/how-do-i-calculate-relative-time However it contains missing arguments. How could this be used in Objective-C?. Thanks. const int SECOND = 1; const int MINUTE = 60 * SECOND; const int HOUR = 60 * MINUTE; const int DAY = 24 * HOUR; const int MONTH = 30 * DAY; if (delta < 1 * MINUTE) { return ts.Seconds == 1 ? "one second ago" : ts.Seconds + " seconds ago"; } if (delta < 2 * MINUTE) { return "a minute ago"; } if (delta < 45 * MINUTE) { return ts.Minutes + " minutes ago"; } if (delta < 90 * MINUTE) { return "an hour ago"; } if (delta < 24 * HOUR) { return ts.Hours + " hours ago"; } if (delta < 48 * HOUR) { return "yesterday"; } if (delta < 30 * DAY) { return ts.Days + " days ago"; } if (delta < 12 * MONTH) { int months = Convert.ToInt32(Math.Floor((double)ts.Days / 30)); return months <= 1 ? "one month ago" : months + " months ago"; } else { int years = Convert.ToInt32(Math.Floor((double)ts.Days / 365)); return years <= 1 ? "one year ago" : years + " years ago"; }

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  • How can I make an AdvancedDataGrid re-display its labels when the results of the labelFunction chang

    - by Chris R
    I have an AdvancedDataGrid with a custom label function whose value can change based on other form status (specifically, there's a drop down to choose the time display format for some columns). Right now, I have this labelFunction: internal function formatColumnTime(item: Object, column: AdvancedDataGridColumn): String { var seconds: Number = item[column.dataField]; return timeFormat.selectedItem.labelFunction(seconds); } internal function formatTimeAsInterval(time: Number): String { if (isNaN(time)) return ""; var integerTime: int = Math.round(time); var seconds: int = integerTime % 60; integerTime = integerTime / 60; var minutes: int = integerTime % 60; var hours: int = integerTime / 60; return printf("%02d:%02d:%02d", hours, minutes, seconds); } internal function formatTimeAsFractions(time: Number): String { if (isNaN(time)) return ""; var hours: Number = time / 3600.0; return new String(Math.round(hours * 100) / 100); } ... and the timeFormat object is a combo box with items whose labelFunction attributes are formatTimeAsFractions and formatTimeAsInterval. The columns that have time formats have formatColumnTime as their labelFunction value, because extracting the seconds in that function and passing it in to the formatters made for a more testable app (IMHO). So, when the timeFormat.selectedItem value changes, I want to force my grid to re-calculate the labels of these colums. What method must I call on it? invalidateProperties() didn't work, so that's out.

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  • correct fisheye distortion

    - by Will
    I have some points that describe positions in a picture taken with a fisheye lens. I've found this description of how to generate a fisheye effect, but not how to reverse it. How do you calculate the radial distance from the centre to go from fisheye to rectilinear? My function stub looks like this: Point correct_fisheye(const Point& p,const Size& img) { // to polar const Point centre = {img.width/2,img.height/2}; const Point rel = {p.x-centre.x,p.y-centre.y}; const double theta = atan2(rel.y,rel.x); double R = sqrt((rel.x*rel.x)+(rel.y*rel.y)); // fisheye undistortion in here please //... change R ... // back to rectangular const Point ret = Point(centre.x+R*cos(theta),centre.y+R*sin(theta)); fprintf(stderr,"(%d,%d) in (%d,%d) = %f,%f = (%d,%d)\n",p.x,p.y,img.width,img.height,theta,R,ret.x,ret.y); return ret; }

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  • Oracle performance problems with large batch of XSL operations

    - by FrustratedWithFormsDesigner
    I have a system that is performing many XSL transformations on XMLType objects. The problem is that the system gradually slows down over time, and sometimes crashes when it runs out of memory. It seems that the slow down (and possibly memory crash) is around the dbms_xslprocessor.processXSL function call, which gradually takes longer and longer to complete. The code looks like this: v_doc dbms_xmldom.DOMDocument; v_transformer dbms_xmldom.DOMDocument; v_XSLprocessor dbms_xslprocessor.Processor; v_stylesheet dbms_xslprocessor.Stylesheet; v_clob clob; ... transformer := PKG_STUFF.getXSL(); v_transformer := dbms_xmldom.newDOMDocument(transformer); v_XSLprocessor := Dbms_Xslprocessor.newProcessor; v_stylesheet := dbms_xslprocessor.newStylesheet(v_transformer, ''); ... for source_data in (select id in source_tbl) loop begin v_doc := PKG_CONVERT.convert(in_id => source_data.id); --start time of operation v_begin_op_time := dbms_utility.get_time; --reset the CLOB v_clob := ' '; --Apply XSL Transform dbms_xslprocessor.processXSL(p => v_XSLprocessor, ss => v_stylesheet, xmldoc => v_Doc, cl => v_clob); v_doc := dbms_xmldom.newDOMDocument(XMLType(v_clob)); --end time v_end_op_time := dbms_utility.get_time; --calculate duration v_time_taken := (((v_end_op_time - v_begin_op_time))); --log the duration PKG_LOG.log_message('Time taken to transform XML: '||v_time_taken); ... ... DBMS_XMLDOM.freeDocument(v_Doc); DBMS_LOB.freetemporary(lob_loc => v_clob); end loop; The time taken to transform the XML is slowly creeping up (I suppose it might also be the call to dbms_xmldom.newDOMDocument, but I had thought that to be fairly straightforward). I have no idea why.... :( (Oracle 10g)

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  • How to optimize this algorithm?

    - by Bakhtiyor
    I have two sets of arrays like this for example. $Arr1['uid'][]='user 1'; $Arr1['weight'][]=1; $Arr1['uid'][]='user 2'; $Arr1['weight'][]=10; $Arr1['uid'][]='user 3'; $Arr1['weight'][]=5; $Arr2['uid'][]='user 1'; $Arr2['weight'][]=3; $Arr2['uid'][]='user 4'; $Arr2['weight'][]=20; $Arr2['uid'][]='user 5'; $Arr2['weight'][]=15; $Arr2['uid'][]='user 2'; $Arr2['weight'][]=2; The size of two arrays could be different of course. $Arr1 has coefficient of 0.7 and $Arr2 has coefficient of 0.3. I need to calculate following formula $result=$Arr1['weight'][$index]*$Arr1Coeff+$Arr2['weight'][$index]*$Arr2Coeff; where $Arr1['uid']=$Arr2['uid']. So when $Arr1['uid'] doesn't exists in $Arr2 then we need to omit $Arr2 and vice versa. And, here is an algorithm I am using now. foreach($Arr1['uid'] as $index=>$arr1_uid){ $pos=array_search($arr1_uid, $Arr2['uid']); if ($pos===false){ $result=$Arr1['weight'][$index]*$Arr1Coeff; echo "<br>$arr1_uid has not found and RES=".$result; }else{ $result=$Arr1['weight'][$index]*$Arr1Coeff+$Arr2['weight'][$pos]*$Arr2Coeff; echo "<br>$arr1_uid has found on $pos and RES=".$result; } } foreach($Arr2['uid'] as $index=>$arr2_uid){ if (!in_array($arr2_uid, $Arr1['uid'])){ $result=$Arr2['weight'][$index]*$Arr2Coeff; echo "<br>$arr2_uid has not found and RES=".$result; }else{ echo "<br>$arr2_uid has found somewhere"; } } The question is how can I optimize this algorithm? Can you offer other better solution for this problem? Thank you.

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  • Composite key syntax in Boost MultiIndex

    - by Sarah
    Even after studying the examples, I'm having trouble figuring out how to extract ranges using a composite key on a MultiIndex container. typedef multi_index_container< boost::shared_ptr< Host >, indexed_by< hashed_unique< const_mem_fun<Host,int,&Host::getID> >, // ID index ordered_non_unique< const_mem_fun<Host,int,&Host::getAgeInY> >, // Age index ordered_non_unique< const_mem_fun<Host,int,&Host::getHousehold> >, // Household index ordered_non_unique< // Age & eligibility status index composite_key< Host, const_mem_fun<Host,int,&Host::getAgeInY>, const_mem_fun<Host,bool,&Host::isPaired> > > > // end indexed_by > HostContainer; My goal is to get an iterator pointing to the first of the subset of elements in HostContainer hmap that has age partnerAge and returns false to Host::isPaired(): std::pair< hmap::iterator,hmap::iterator > pit = hmap.equal_range(boost::make_tuple( partnerAge, false ) ); I think this is very wrong. How/Where do I specify the iterator index (which should be 3 for age & eligibility)? I will include other composite keys in the future. What exactly are the two iterators in std::pair? (I'm copying syntax from an example that I don't understand.) I would ideally use std::count to calculate the number of elements of age partnerAge that are eligible (return false to Host::isPaired()). What is the syntax for extracting the sorted index that meets these requirements? I'm obviously still learning C++ syntax. Thanks in advance for any help.

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  • OpenNETCF.Stopwatch -> only ticks changing, not Elapsed

    - by pithyless
    I've been trying to track down a bug I thought was thread-related, but I think instead there is an issue with the way I am using OpenNETCF's Stopwatch. I am using OpenNETCF.IoC in my application, but for the sake of simplicity I moved the following code directly into a view: public partial class WorkoutView : SmartPart { ... private Stopwatch stopwatch; public WorkoutView() { ... stopwatch = new Stopwatch(); stopwatch.Reset(); stopwatch.Start(); WorkoutDisplayTimer = new Timer(); WorkoutDisplayTimer.Interval = 500; WorkoutDisplayTimer.Tick += new EventHandler(WorkoutDisplayTimer_Tick); WorkoutDisplayTimer.Enabled = true; } void WorkoutDisplayTimer_Tick(object sender, EventArgs e) { ... stopwatch.Stop(); lbl.Text = stopwatch.ElapsedTicks.ToString() + "NOT WORKING: " + stopwatch.Elapsed.ToString(); stopwatch.Start(); } ... } Long story short, looking at stopwatch in the debugger, the only values that ever get updated are ElapsedTicks, mElapsed, mStartPerfCount. Everything else is always zero. Is this expected behavior? Do I need to call an additional method to have the stopwatch calculate the Elapsed struct? (Note: stopwatch.ElapsedMilliseconds is also zero)

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  • stock management of assemblys and its sub parts

    - by The Disintegrator
    I have to track the stock of individual parts and kits (assembly) and can't find a satisfactory way of doing this. Sample bogus and hyper simplified database: Table prod: prodID 1 prodName Flux capacitor prodCost 900 prodPrice 1350 (900*1.5) prodStock 3 - prodID 2 prodName Mr Fusion prodCost 300 prodPrice 600 (300*2) prodStock 2 - prodID 3 prodName Time travel kit prodCost 1650 (1350+300) prodPrice 2145 (1650*1.3) prodStock 2 Table rels relID 1 relSrc 1 (Flux capacitor) relType 4 (is a subpart of) relDst 3 (Time travel kit) - relID 2 relSrc 2 (Mr Fusion) relType 4 (is a subpart of) relDst 3 (Time travel kit) prodPrice: it's calculated based on the cost but not in a linear way. In this example for costs of 500 or less, the markup is a 200%. For costs of 500-1000 the markup is 150%. For costs of 1000+ the markup is 130% That's why the time travel kit is much cheaper than the individual parts prodStock: here is my problem. I can sell kits or the individual parts, So the stock of the kits is virtual. The problem when I buy: Some providers sell me the Time Travel kit as a whole (with one barcode) and some sells me the individual parts (with a different barcode) So when I load the stock I don't know how to impute it. The problem when I sell: If I only sell kits, calculate the stock would be easy: "I have 3 Flux capacitors and 2 Mr Fusions, so I have 2 Time travel kits and a Flux Capacitor" But I can sell Kits or individual parts. I have to track the stock of the individual parts and the possible kits at the same time (and I have to compensate for the sell price) Probably this is really simple, but I can't see a simple solution. Resuming: I have to find a way of tracking the stock and the database/program is the one who has to do it (I cant ask the clerk to correct the stock) I'm using php+MySql. But this is more a logical problem than a programing one

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  • theoretical and practical matrix multiplication FLOP

    - by mjr
    I wrote traditional matrix multiplication in c++ and tried to measure and compare its theoretical and practical FLOP. As I know inner loop of MM has 2 operation therefore simple MM theoretical Flops is 2*n*n*n (2n^3) but in practice I get something like 4n^3 + number of operation which is 2 i.e. 6n^3 also if I just try to add up only one array a[i][j]++ practical flops then calculate like 3n^3 and not n^3 as you see again it is 2n^3 +1 operation and not 1 operation * n^3 . This is in case if I use 1D array in three nested loops as Matrix multiplication and compare flop, practical flop is the same (near) the theoretical flop and depend exactly as the number of operation in inner loop.I could not find the reason for this behaviour. what is the reason in both case? I know that theoretical flop is not the same as practical one because of some operations like load etc. system specification: Intel core2duo E4500 3700g memory L2 cache 2M x64 fedora 17 sample results: Matrix matrix multiplication 512*512 Real_time: 1.718368 Proc_time: 1.227672 Total flpops: 807,107,072 MFLOPS: 657.429016 Real_time: 3.608078 Proc_time: 3.042272 Total flpops: 807,024,448 MFLOPS: 265.270355 theoretical flop: 2*512*512*512=268,435,456 Practical flops= 6*512^3 =807,107,072 Using 1 dimensional array float d[size][size]:512 or any size for (int j = 0; j < size; ++j) { for (int k = 0; k < size; ++k) { d[k]=d[k]+e[k]+f[k]+g[k]+r; } } Real_time: 0.002288 Proc_time: 0.002260 Total flpops: 1,048,578 MFLOPS: 464.027161 theroretical flop: *4n^2=4*512^2=1,048,576* practical flop : 4n^2+overhead (other operation?)=1,048,578 3 loop version: Real_time: 1.282257 Proc_time: 1.155990 Total flpops: 536,872,000 MFLOPS: 464.426117 theoretical flop:4n^3 = 536,870,912 practical flop: *4n^3=4*512^3+overheads(other operation?)=536,872,000* thank you

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  • optimize query: get al votes from user's item

    - by Toni Michel Caubet
    hi there! i did it my way because i'm very bad getting results from two tables... Basically, first i get all the id items that correspond to the user, and then i calculate the ratings of each item. But, there is two different types of object item, so i do this 2 times: show you: function votos_usuario($id){ $previa = "SELECT id FROM preguntas WHERE id_usuario = '$id'"; $r_previo = mysql_query($previa); $ids_p = '0, '; while($items_previos = mysql_fetch_array($r_previo)){ $ids_p .= $items_previos['id'].", "; //echo "ids pregunta usuario: ".$items_previos['id']."<br>"; } $ids = substr($ids_p,0,-2); //echo $ids; $consulta = "SELECT valor FROM votos_pregunta WHERE id_pregunta IN ( $ids )"; //echo $consulta; $resultado = mysql_query($consulta); $votos_preguntas = 0; while($voto = mysql_fetch_array($resultado)){ $votos_preguntas = $votos_preguntas + $voto['valor']; } $previa_r = "SELECT id FROM recetas WHERE id_usuario = '$id'"; $r_previo_r = mysql_query($previa_r); $ids_r = '0, '; while($items_previos_r = mysql_fetch_array($r_previo_r)){ $ids_r .= $items_previos_r['id'].", "; //echo "ids pregunta usuario: ".$items_previos['id']."<br>"; } $ids = substr($ids_r,0,-2); $consulta_b = "SELECT valor FROM votos_receta WHERE id_receta IN ( $ids )"; //echo $consulta; $resultado_b = mysql_query($consulta_b); $votos_recetas = 0; while($voto_r = mysql_fetch_array($resultado_b)){ $votos_recetas = $votos_recetas + $voto_r['valor']; } $total = $votos_preguntas + $votos_recetas; return $total; } As you can si this is two much.. O(n^2) Feel like thinking? thanks!

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  • Questions on usages of sizeof

    - by Appu
    Question 1 I have a struct like, struct foo { int a; char c; }; When I say sizeof(foo), i am getting 8 on my machine. As per my understanding, 4 bytes for int, 1 byte for char and 3 bytes for padding. Is that correct? Given a struct like the above, how will I find out how many bytes will be added as padding? Question 2 I am aware that sizeof can be used to calculate the size of an array. Mostly I have seen the usage like (foos is an array of foo) sizeof(foos)/sizeof(*foos) But I found that the following will also give same result. sizeof(foos) / sizeof(foo) Is there any difference in these two? Which one is preffered? Question 3 Consider the following statement. foo foos[] = {10,20,30}; When I do sizeof(foos) / sizeof(*foos), it gives 2. But the array has 3 elements. If I change the statement to foo foos[] = {{10},{20},{30}}; it gives correct result 3. Why is this happening? Any thoughts..

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  • Best fit curve for trend line

    - by Dave Jarvis
    Problem Constraints Size of the data set, but not the data itself, is known. Data set grows by one data point at a time. Trend line is graphed one data point at a time (using a spline/Bezier curve). Graphs The collage below shows data sets with reasonably accurate trend lines: The graphs are: Upper-left. By hour, with ~24 data points. Upper-right. By day for one year, with ~365 data points. Lower-left. By week for one year, with ~52 data points. Lower-right. By month for one year, with ~12 data points. User Inputs The user can select: the type of time series (hourly, daily, monthly, quarterly, annual); and the start and end dates for the time series. For example, the user could select a daily report for 30 days in June. Trend Weight To calculate the window size (i.e., the number of data points to average when calculating the trend line), the following expression is used: data points / trend weight Where data points is derived from user inputs and trend weight is 6.4. Even though a trend weight of 6.4 produces good fits, it is rather arbitrary, and might not be appropriate for different user inputs. Question How should trend weight be calculated given the constraints of this problem?

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