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  • Venture Capital SEO (Search Engine Optimization)

    Back in the day, venture capitalists relied on tips, networking and brute force to find companies to invest in. Typically, more of their time was spent actively searching for leads than marketing their services. The internet changed all of that. A quick resource for start-up companies looking for companies to invest in them, today's venture capitalists have been forced to change the way they do business - now they must spend more of their time advertising.

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  • How to Promote a New Website

    Promoting a website is not a work of one day or one week, it takes time to improve a website's position on search engines. And if your website is a new one then it takes more time.

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  • How Do SEO Consultancies Work?

    SEO Consultancies have a very different way of working and functioning. Enterprises that want to have their websites optimized approach the consultancies to either take up the assignment full time or provide part time consulting services.

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  • Make Your Own Website - It is Easier Than You Imagine!

    If you are thinking that it would be far too hard to even consider making your own website, it is time to think again! Building your own website has never been easier, together with the greatly reduced cost of building and maintaining your site, the time has never been better.

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  • ?????? ??????????! ?Gold???? vol.3 <??>

    - by M.Morozumi
    ???ORACLE MASTER Gold Oracle Database 11g?????????????? ?????????????????????? ------------------------------- ???? Point-in-Time ?????????????????????????????????( )??????????????? ( )???????????????1????????? a.TS_PITR_OBJECTS_TO_BE_OBSOLETED b.TS_PITR_OBJECTS_TO_BE_DISAPPEARED c.TS_PITR_OBJECTS_TO_BE_DROPPED ??????????????? ------------------------------- ??:c.TS_PITR_OBJECTS_TO_BE_DROPPED ??: ???? Point-in-Time ?????????????????????????????????TS_PITR_OBJECTS_TO_BE_DROPPED ????????????????????????????????

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  • Programmatically controlling Chart in Silverlight toolkit

    - by Manoj
    Hi, I want to control the x and y axis of a multi series line charts available in Silverlight toolkit from the C# code. I am not able to find any appropriate example using google. Any kind of example or pointers would be appreciated! EDIT: This is what I have done so far: <toolkit:Chart Canvas.Left="104" Canvas.Top="18" Name="chartCompare" Title="Compare Series" Height="285" Width="892"> <toolkit:LineSeries Title="SP1" Name="Series1"/> </toolkit:Chart> And in the code behind I am trying this: Series1.ItemsSource = ObjectList; Series1.IndependentValuePath = "Val1"; Series1.DependentValuePath = "Val2"; Where ObjectList is a List of Objects which has val1 and val2 as its property. But it is throwing an error when I run this in Line "Series1.ItemsSource = ObjectList;" saying "Object reference not set to an instance of an object..". I have initialised and set its value just in the line before it. Actually I have set this as an item source for a data grid in the line before it and it works fine.

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  • Async.Parallel or Array.Parallel.Map ?

    - by gurteen2
    Hello- I'm trying to implement a pattern I read from Don Syme's blog (http://blogs.msdn.com/dsyme/archive/2010/01/09/async-and-parallel-design-patterns-in-f-parallelizing-cpu-and-i-o-computations.aspx) which suggests that there are opportunities for massive performance improvements from leveraging asynchronous I/O. I am currently trying to take a piece of code that "works" one way, using Array.Parallel.Map, and see if I can somehow achieve the same result using Async.Parallel, but I really don't understand Async.Parallel, and cannot get anything to work. I have a piece of code (simplified below to illustrate the point) that successfully retrieves an array of data for one cusip. (A price series, for example) let getStockData cusip = let D = DataProvider() let arr = D.GetPriceSeries(cusip) return arr let data = Array.Parallel.map (fun x -> getStockData x) stockCusips So this approach contructs an array of arrays, by making a connection over the internet to my data vendor for each stock (which could be as many as 3000) and returns me an array of arrays (1 per stock, with a price series for each one). I admittedly don't understand what goes on underneath Array.Parallel.map, but am wondering if this is a scenario where there are resources wasted under the hood, and it actually could be faster using asynchronous I/O? So to test this out, I have attempted to make this function using asyncs, and I think that the function below follows the pattern in Don Syme's article using the URLs, but it won't compile with "let!". let getStockDataAsync cusip = async { let D = DataProvider() let! arr = D.GetData(cusip) return arr } The error I get is: This expression was expected to have type Async<'a but here has type obj It compiles fine with "let" instead of "let!", but I had thought the whole point was that you need the exclamation point in order for the command to run without blocking a thread. So the first question really is, what's wrong with my syntax above, in getStockDataAsync, and then at a higher level, can anyone offer some additional insight about asychronous I/O and whether the scenario I have presented would benefit from it, making it potentially much, much faster than Array.Parallel.map? Thanks so much.

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  • People not respecting good practices at workplace

    - by VexXtreme
    Hi There are some major issues in my company regarding practices, procedures and methodologies. First of all, we're a small firm and there are only 3-4 developers, one of which is our boss who isn't really a programmer, he just chimes in now and then and tries to do code some simple things. The biggest problems are: Major cowboy coding and lack of methodologies. I've tried explaining to everyone the benefits of TDD and unit testing, but I only got weird looks as if I'm talking nonsense. Even the boss gave me the reaction along the lines of "why do we need that? it's just unnecessary overhead and a waste of time". Nobody uses design patterns. I have to tell people not to write business logic in code behind, I have to remind them not to hardcode concrete implementations and dependencies into classes and cetera. I often feel like a nazi because of this and people think I'm enforcing unnecessary policies and use of design patterns. The biggest problem of all is that people don't even respect common sense security policies. I've noticed that college students who work on tech support use our continuous integration and source control server as a dump to store their music, videos, series they download from torrents and so on. You can imagine the horror when I realized that most of the partition reserved for source control backups was used by entire seasons of TV series and movies. Our development server isn't even connected to an UPS and surge protection. It's just plugged straight into the wall outlet. I asked the boss to buy surge protection, but he said it's unnecessary. All in all, I like working here because the atmosphere is very relaxed, money is good and we're all like a family (so don't advise me to quit), but I simply don't know how to explain to people that they need to stick to some standards and good practices in IT industry and that they can't behave so irresponsibly. Thanks for the advice

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  • Mocking WebResponse's from a WebRequest

    - by Rob Cooper
    I have finally started messing around with creating some apps that work with RESTful web interfaces, however, I am concerned that I am hammering their servers every time I hit F5 to run a series of tests.. Basically, I need to get a series of web responses so I can test I am parsing the varying responses correctly, rather than hit their servers every time, I thought I could do this once, save the XML and then work locally. However, I don't see how I can "mock" a WebResponse, since (AFAIK) they can only be instantiated by WebRequest.GetResponse How do you guys go about mocking this sort of thing? Do you? I just really don't like the fact I am hammering their servers :S I dont want to change the code too much, but I expect there is a elegant way of doing this.. Update Following Accept Will's answer was the slap in the face I needed, I knew I was missing a fundamental point! Create an Interface that will return a proxy object which represents the XML. Implement the interface twice, on that uses WebRequest, the other that returns static "responses". The interface implmentation then either instantiates the return type based on the response, or the static XML. You can then pass the required class when testing or at production to the service layer. Once I have the code knocked up, I'll paste some samples. Thanks Will :)

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  • onmouseover with django / imagekit

    - by Michael Moreno
    I'm using Imagekit. View.py includes: def pics(request): p = Photo.objects.all() return render_to_response('Shots.html', {'p': p}) The following simple code in the template will generate associated images: {% for p in p %} <img src = "{{ p.display.url }}"> <img src = "{{ p.thumbnail_image.url }}"> {% endfor %} I'm attempting to generate a series of thumbnails {{ p.thumbnail_image.url }} which, when mouseover'd, will generate the slightly larger version of the image, {{ p.display.url }} via Javascript. The following code in the template attempts to do so: <html> <head> <HEAD> <script language="Javascript"> { image1 = new Image image2 = new Image image1.src = {{ p.thumbnail_image.url }} image2.src = {{ p.display.url }} </script> </head> <body> {% for p in p %} <a href="" onMouseOver="document.rollover.src= image2.src onMouseOut="document.rollover.src= image1.src"> <img src="{{ p.thumbnail_image.url }}" border=0 name="rollover"></a> {% endfor %} </body> </html> This will display the series of thumbnails, but the larger image will not display when mouseover'd. I believe it has to do with how I'm specifying the variable {{ p.display.url }}.

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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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  • onmouseover problems with JavaScript (rendered using django and django-imagekit)

    - by Michael Moreno
    I'm using Imagekit. View.py includes: def pics(request): p = Photo.objects.all() return render_to_response('Shots.html', {'p': p}) The following simple code in the template will generate associated images: {% for p in p %} <img src = "{{ p.display.url }}"> <img src = "{{ p.thumbnail_image.url }}"> {% endfor %} I'm attempting to generate a series of thumbnails {{ p.thumbnail_image.url }} which, when mouseover'd, will generate the slightly larger version of the image, {{ p.display.url }} via Javascript. The following code in the template attempts to do so: <html> <head> <HEAD> <script language="Javascript"> { image1 = new Image image2 = new Image image1.src = {{ p.thumbnail_image.url }} image2.src = {{ p.display.url }} </script> </head> <body> {% for p in p %} <a href="" onMouseOver="document.rollover.src= image2.src onMouseOut="document.rollover.src= image1.src"> <img src="{{ p.thumbnail_image.url }}" border=0 name="rollover"></a> {% endfor %} </body> </html> This will display the series of thumbnails, but the larger image will not display when mouseover'd. I believe it has to do with how I'm specifying the variable {{ p.display.url }}.

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  • PyQt4: Hide widget and resize window

    - by masterLoki
    Hi everyone: I'm working with several widgets but the solution just won't come out. What I have is a series of buttons in series of QHBoxLayouts. Some buttons are hidden by default, but they will appear when needed. To solve space issues, all buttons have a minimum and maximum size so they always look well packed. Also I have a QTextEdit, visible by default, which is in a QVBoxLayout with the QHBoxLayout that hold the buttons So the problem is this: When I hide the QTextEdit and show the other buttons, the window won't resize. After searching I found that using self.ui.layout().setSizeConstraint(QtGui.QLayout.SetFixedSize) will do the trick, but the problem is that it takes the maximum size from all widgets, therefore I end a huge window. Doing self.ui.layout().setSizeConstraint(QtGui.QLayout.SetMinAndMaxSize) won't resize the window I already tried using self.ui.resize(0,0), and when doing a self.ui.layout().update() I got False (which I find odd, http://doc.trolltech.com/4.6/qlayout.html#activate), and also tried to override sizeHint() but it keeps using the max size for all widgets. Is there a way to resize the window and while taking care of the min and max size of a widget? Thanks in advance

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  • In PHP... best way to turn string representation of a folder structure into nested array

    - by Greg Frommer
    Hi everyone, I looked through the related questions for a similar question but I wasn't seeing quite what I need, pardon if this has already been answered already. In my database I have a list of records that I want represented to the user as files inside of a folder structure. So for each record I have a VARCHAR column called "FolderStructure" that I want to identify that records place in to the folder structure. The series of those flat FolderStructure string columns will create my tree structure with the folders being seperated by backslashes (naturally). I didn't want to add another table just to represent a folder structure... The 'file' name is stored in a separate column so that if the FolderStructure column is empty, the file is assumed to be at the root folder. What is the best way to turn a collection of these records into a series of HTML UL/LI tags... where each LI represents a file and each folder structure being an UL embedded inside it's parent?? So for example: file - folderStructure foo - bar - firstDir blue - firstDir/subdir would produce the following HTML: <ul> <li>foo</li> <ul> <li> bar </li> <ul> <li> blue </li> </ul> </ul> </ul> Thanks

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  • Javascript keyup doesn't work as expected, it executes in instances where I have not removed my fing

    - by Binni
    I'm trying to create a simple game in javascript and I'm stuck on how to deal with keys. Small example: function keyUpEvent(event) { alert(event.keyCode); } window.addEventListener("keyup", keyUpEvent, false); I'm running Ubuntu 9.10 and testing it in Firefox 3.5 and Chromium. If I press and release a button instantly I get an alert, which is to be expected, but when I press and hold a button I get a small pause and then a series of alert windows, the expected result is that I only get an alert window when I remove my finger from a button. I reason it has something to do with the fact that when I press and hold a button in a text area for example I get one character, small pause, and then a series of characters: dddddddddddddddd. I believe it's possible to get around this or do it more right or whatever since this game for example: http://bohuco.net/testing/gamequery/pong.html seams not to be affected by this. But I notice if I try out the jquery keyup demo ( api.jquery.com/keyup/ ) I get the same problem. How can I implement basic game key event handling?

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  • Array Recursion

    - by GeeYouAreYou
    I've got an assignment I can't figure out, any pointers will be much appreciated, it goes like so: There's a series of light bulbs represented as an array of true/false, there's a switch for every light bulb, by clicking it for any light bulb, you toggle it as well as 2 adjacent ones (1 from left & another 1 from right; if clicked switch's bulb on edge -- only 1 adjacent toggled of course). What is needed to accomplish is a method that accepts an array of a series of turned on/off light bulbs and another one representing another state of supposedly the 1st array after some switches have been clicked..! So recursion must be used to find out whether there's a combination of switch clicks that will transform array 1 to array 2. Here's the signature of the method: public static boolean disco(boolean[] init, boolean[] target) Will return true if array init can be transformed to target, false otherwise. Method must be static and not use any other static and global variables, only local. Example: boolean[] init = {true, false, true, false, true, false}; boolean[] target = {false, true, false, true, false, true}; For above 2 arrays, disco(init, target) will return true because toggling the 1st and 4th bulbs would yield the target state (remember adjacent bulbs being toggled as well). Any help much appreciated..!!

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  • Summation loop program in Pascal

    - by user2526598
    I am having a bit of an issue with this problem. I am taking a Pascal programming class and this problem was in my logic book. I am required to have the user enter a series of (+) numbers and once he/she enters a (-) number, the program should find the sum of all the (+) numbers. I accomplished this, but now I am attempting part two of this problem, which requires me to utilize a nested loop to run the program x amount of times based on the user's input. The following code is what I have so far and honestly I am stumped: program summation; //Define main program's variables var num, sum, numRun : integer; //Design procedure that will promt user for number of runs procedure numRunLoop ( var numRun : integer ); begin writeln('How many times shall I run this program?'); readln(numRun); end; //Design procedure that will sum a series of numbers //based on user input procedure numPromptLoop( numRun : integer; var num : integer ); var count : integer; begin //Utilize for to establish run limit for count := 1 to numRun do begin //Use repeat to prompt user for numbers repeat writeln('Enter a number: '); readln(num); //Tells program when to sum if num >= 0 then sum := sum + num; until num < 0; end; end; //Design procedure that will display procedure addItion( sum : integer ); begin writeln('The sum is; ', sum); end; begin numRunLoop(numRun); numPromptloop(numRun, num); addItion(sum); readln(); end.

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  • ExtJS 4 Chart Axis Display Issue in Chrome

    - by SerEnder
    I've run into an issue while using ExtJS 4.0.7. I'm trying to display a chart with two series on a Numeric/Category Chart. The chart displays correctly in Firefox, but while using Chrome (18.0.1025.142) the x axis labels are either all stacked upon each or else (when using rotate) rendered behind the chart in the specified angle. Any ideas would be appreciated. Screen shot in Firefox: Screen Shot in Chrome: And the code that's used to generate both: Ext.require(['Ext.chart.*']); Ext.onReady(function() { var iChartWidth = 800; // Defines chart width var iChartHeight = 550; // Defines chart height Ext.define('RulesCreatedModel',{ extend:'Ext.data.Model', fields:[ {name:'sHourName', type:'string'}, {name:'User_2', type:'number'}, {name:'User_1', type:'number'}, ] }); var RulesCreatedStore = Ext.create('Ext.data.Store',{ id:'RulesCreatedStore', model:'RulesCreateModel', fields: [ 'sHourName','dayNum','hour','User_2','User_1'], data:[{ 'sHourName':'3pm', 'User_1':82, 'User_2':56 },{ 'sHourName':'4pm', 'User_1':39, 'User_2':44 },{ 'sHourName':'5pm', 'User_1':80, 'User_2':14 },{ 'sHourName':'6pm', 'User_1':55, 'User_2':0, },{ 'sHourName':'7pm', 'User_1':36, 'User_2':0, },{ 'sHourName':'8pm', 'User_1':66, 'User_2':0 },{ 'sHourName':'9pm', 'User_1':39, 'User_2':0, },{ 'sHourName':'10pm', 'User_1':0, 'User_2':0 },{ 'sHourName':'11pm', 'User_1':0, 'User_2':0 },{ 'sHourName':'12am', 'User_1':0, 'User_2':0 },{ 'sHourName':'1am', 'User_1':0, 'User_2':0 },{ 'sHourName':'2am', 'User_1':0, 'User_2':0 },{ 'sHourName':'3am', 'User_1':0, 'User_2':0 },{ 'sHourName':'4am', 'User_1':0, 'User_2':0 },{ 'sHourName':'5am', 'User_1':0, 'User_2':0 },{ 'sHourName':'6am', 'User_1':0, 'User_2':0 },{ 'sHourName':'7am', 'User_1':0, 'User_2':1 },{ 'sHourName':'8am', 'User_1':0, 'User_2':99 },{ 'sHourName':'9am', 'User_1':0, 'User_2':28 },{ 'sHourName':'10am', 'User_1':0, 'User_2':28 },{ 'sHourName':'11am', 'User_1':0, 'User_2':153 },{ 'sHourName':'12pm', 'User_1':0, 'User_2':58 },{ 'sHourName':'1pm', 'User_1':0, 'User_2':42 },{ 'sHourName':'2pm', 'User_1':20, 'User_2':10 }] }); Ext.create('Ext.chart.Chart',{ id: 'RulesWrittenChart', renderTo: 'StatCharts_Display', width: iChartWidth, height: iChartHeight, animate: true, store: RulesCreatedStore, axes: [{ type: 'Numeric', position: 'left', fields: ['User_2','User_1'], title: 'Rules Written', grid: true },{ type: 'Category', position: 'bottom', fields: ['sHourName'], title: 'Hour', grid: false, label: { rotate: { degrees: 315 } } }], series: [{ type: 'line', axis: 'left', xField: 'sHourName', yField: 'User_2', highlight: { size: 3, radius: 3 } },{ type: 'line', axis: 'left', xField: 'sHourName', yField: 'User_1', highlight: { size: 3, radius: 3 } }] }); });

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  • Java OO design confusion: how to handle actions modified by states modified by actions...

    - by Arvanem
    Hi folks, Given an entity, whose action is potentially modified by states (of the entity and other entities) in turn potentially modified by other actions (of the entity and other entities) , what is the best way to code or design to handle the potential existence of the modifiers? Speaking metaphorically, I am coding a Java application representing a piano. As you know a piano has keys (which, when pressed, emit sound) and pedals (which, when pressed, modify the keys' sounds). My base class structure is as follows: Entity (for keys and pedals) State (this holds each entity's states, e.g. name such as "soft pedal", and boolean "Pressed"), Action (this holds each entity's actions, e.g. play sound when pressed, or modify others sounds). By composition, the Entity class has a copy of each of State and Action inside it. e.g.: public class Entity { State entityState = new State(); Action entityAction = new Action(); Thus I have coded a "C-Sharp" key Entity. When I "press" that entity (set its "Pressed" state to true), its action plays a "C-Sharp" sound and then sets its "Pressed" state to false. At the same time, if the "C-Sharp" key entity is not "tuned", its sound deviates from "C-Sharp". Meanwhile I have coded a "soft pedal" Entity. When that entity is "pressed", no sound plays but its action is to make softer the sound of the "C-Sharp" and other key entities. I have also coded a "sustain pedal" Entity. When that entity is "pressed", no sound plays but its action is to enable reverberation of the sound of the "C-Sharp" and other key entities. Both the "soft" and "sustain pedals" can be pressed at the same time with the result that keys entities become both softened and reverberating. In short, I do not understand how to make this simultaneous series of states and actions modify each other in a sensible OO way. I am wary of coding a massive series of "if" statements or "switches". Thanks in advance for any help or links you can offer.

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  • Calculate posterior distribution of unknown mis-classification with PRTools in MATLAB

    - by Samuel Lampa
    I'm using the PRTools MATLAB library to train some classifiers, generating test data and testing the classifiers. I have the following details: N: Total # of test examples k: # of mis-classification for each classifier and class I want to do: Calculate and plot Bayesian posterior distributions of the unknown probabilities of mis-classification (denoted q), that is, as probability density functions over q itself (so, P(q) will be plotted over q, from 0 to 1). I have that (math formulae, not matlab code!): P(q|k,N) = Posterior * Prior / Normalization constant = P(k|q,N) * P(q|N) / P(k|N) The prior is set to 1, so I only need to calculate the posterior and normalization constant. I know that the posterior can be expressed as (where B(N,k) is the binomial coefficient): P(k|q,N) = B(N,k) * q^k * (1-q)^(N-k) ... so the Normalization constant is simply an integral of the posterior above, from 0 to 1: P(k|N) = B(N,k) * integralFromZeroToOne( q^k * (1-q)^(N-k) ) (The Binomial coefficient ( B(N,k) ) can be omitted thoughappears in both the posterior and normalization constant, so it can be omitted.) Now, I've heard that the integral for the normalization constant should be able to be calculated as a series ... something like: k!(N-k)! / (N+1)! Is that correct? (I have some lecture notes from with this series, but can't figure out if it is for the normalization constant integral, or for the posterior distribution of mis-classification (q)) Also, hints are welcome as how to practically calculate this? (factorials are easily creating truncation errors right?) ... AND, how to practically calculate the final plot (the posterior distribution over q, from 0 to 1).

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  • How do I use Spreadsheet::WriteExcel to create a chart from numeric log data?

    - by yaohung
    I used csv2xls.pl to convert a text log into .xls format, and then I create a chart as in the following: my $chart3 = $workbook->add_chart( type => 'line' , embedded => 1); # Configure the series. $chart3->add_series( categories => '=Sheet1!$B$2:$B$64', values => '=Sheet1!$C$2:$C$64', name => 'Test data series 1', ); # Add some labels. $chart3->set_title( name => 'Bridge Rate Analysis' ); $chart3->set_x_axis( name => 'Packet Size ' ); $chart3->set_y_axis( name => 'BVI Rate' ); # Insert the chart into the main worksheet. $worksheet->insert_chart( 'G2', $chart3 ); I can see the chart in the .xls file. However, all the data are in text format, not numeric, so the chart looks wrong. How do I convert text into number before applying this create-chart function? Also, how do I sort the .xls file before creating the chart?

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  • Creating WPF components in background thread

    - by mizipzor
    Im working on a reporting system, a series of DocumentPage are to be created through a DocumentPaginator. These documents include a number of WPF components that are to be instantiated so the paginator includes the correct things when later sent to the XpsDocumentWriter (which in turn is sent to the actual printer). My problem now is that the DocumentPage instances take quite a while to create (enough for Windows to mark the application as frozen) so I tried to create them in a background thread, which is problematic since WPF expects the attributes on them to be set from the GUI thread. I would also like to have a progress bar showing up, indicating how many pages have been created so far. Thus, it looks like Im trying to get two things to happen in parallell on the GUI. The problem is hard to explain and Im really not sure how to tackle it. In short: Create a series of DocumentPage's. These include WPF components These are to be created on a background thread, or use some other trick so the application isnt frozen. After each page is created, a WPF ProgressBar should be updated. If there is no decent way to do this, alternate solutions and approaches are more than welcome.

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  • How to speed-up python nested loop?

    - by erich
    I'm performing a nested loop in python that is included below. This serves as a basic way of searching through existing financial time series and looking for periods in the time series that match certain characteristics. In this case there are two separate, equally sized, arrays representing the 'close' (i.e. the price of an asset) and the 'volume' (i.e. the amount of the asset that was exchanged over the period). For each period in time I would like to look forward at all future intervals with lengths between 1 and INTERVAL_LENGTH and see if any of those intervals have characteristics that match my search (in this case the ratio of the close values is greater than 1.0001 and less than 1.5 and the summed volume is greater than 100). My understanding is that one of the major reasons for the speedup when using NumPy is that the interpreter doesn't need to type-check the operands each time it evaluates something so long as you're operating on the array as a whole (e.g. numpy_array * 2), but obviously the code below is not taking advantage of that. Is there a way to replace the internal loop with some kind of window function which could result in a speedup, or any other way using numpy/scipy to speed this up substantially in native python? Alternatively, is there a better way to do this in general (e.g. will it be much faster to write this loop in C++ and use weave)? ARRAY_LENGTH = 500000 INTERVAL_LENGTH = 15 close = np.array( xrange(ARRAY_LENGTH) ) volume = np.array( xrange(ARRAY_LENGTH) ) close, volume = close.astype('float64'), volume.astype('float64') results = [] for i in xrange(len(close) - INTERVAL_LENGTH): for j in xrange(i+1, i+INTERVAL_LENGTH): ret = close[j] / close[i] vol = sum( volume[i+1:j+1] ) if ret > 1.0001 and ret < 1.5 and vol > 100: results.append( [i, j, ret, vol] ) print results

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  • JavaScript Regex: Complicated input validation

    - by ScottSEA
    I'm trying to construct a regex to screen valid part and/or serial numbers in combination, with ranges. A valid part number is a two alpha, three digit pattern or /[A-z]{2}\d{3}/ i.e. aa123 or ZZ443 etc... A valid serial number is a five digit pattern, or /\d{5}/ 13245 or 31234 and so on. That part isn't the problem. I want combinations and ranges to be valid as well: 12345, ab123,ab234-ab245, 12346 - 12349 - the ultimate goal. Ranges and/or series of part and/or serial numbers in any combination. Note that spaces are optional when specifying a range or after a comma in a series. Note that a range of part numbers has the same two letter combination on both sides of the range (i.e. ab123 - ab239) I have been wrestling with this expression for two days now, and haven't come up with anything better than this: /^(?:[A-z]{2}\d{3}[, ]*)|(?:\d{5}[, ]*)|(?:([A-z]{2})\d{3} ?- ?\4\d{3}[, ]*)|(?:\d{5} ?- ?\d{5}[, ]*)$/ ... My Regex-Fu is weak.

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  • What exactly is the GNU tar ././@LongLink "trick"?

    - by Cheeso
    I read that a tar entry type of 'L' (76) is used by gnu tar and gnu-compliant tar utilities to indicate that the next entry in the archive has a "long" name. In this case the header block with the entry type of 'L' usually encodes the name ././@LongLink . My question is: where is the format of the next block described? The format of a tar archive is very simple: it is just a series of 512-byte blocks. In the normal case, each file in a tar archive is represented as a series of blocks. The first block is a header block, containing the file name, entry type, modified time, and other metadata. Then the raw file data follows, using as many 512-byte blocks as required. Then the next entry. If the filename is longer than will fit in the space allocated in the header block, gnu tar apparently uses what's known as "the ././@LongLink trick". I can't find a precise description for it. When the entry type is 'L', how do I know how long the "long" filename is? Is the long name limited to 512 bytes, in other words, whatever fits in one block? Most importantly: where is this documented?

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