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Search found 1492 results on 60 pages for 'tim buthe'.

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  • Are comonads a good fit for modeling the Wumpus world?

    - by Tim Stewart
    I'm trying to find some practical applications of a comonad and I thought I'd try to see if I could represent the classical Wumpus world as a comonad. I'd like to use this code to allow the Wumpus to move left and right through the world and clean up dirty tiles and avoid pits. It seems that the only comonad function that's useful is extract (to get the current tile) and that moving around and cleaning tiles would not use be able to make use of extend or duplicate. I'm not sure comonads are a good fit but I've seen a talk (Dominic Orchard: A Notation for Comonads) where comonads were used to model a cursor in a two-dimensional matrix. If a comonad is a good way of representing the Wumpus world, could you please show where my code is wrong? If it's wrong, could you please suggest a simple application of comonads? module Wumpus where -- Incomplete model of a world inhabited by a Wumpus who likes a nice -- tidy world but does not like falling in pits. import Control.Comonad -- The Wumpus world is made up of tiles that can be in one of three -- states. data Tile = Clean | Dirty | Pit deriving (Show, Eq) -- The Wumpus world is a one dimensional array partitioned into three -- values: the tiles to the left of the Wumpus, the tile occupied by -- the Wumpus, and the tiles to the right of the Wumpus. data World a = World [a] a [a] deriving (Show, Eq) -- Applies a function to every tile in the world instance Functor World where fmap f (World as b cs) = World (fmap f as) (f b) (fmap f cs) -- The Wumpus world is a Comonad instance Comonad World where -- get the part of the world the Wumpus currently occupies extract (World _ b _) = b -- not sure what this means in the Wumpus world. This type checks -- but does not make sense to me. extend f w@(World as b cs) = World (map world as) (f w) (map world cs) where world v = f (World [] v []) -- returns a world in which the Wumpus has either 1) moved one tile to -- the left or 2) stayed in the same place if the Wumpus could not move -- to the left. moveLeft :: World a -> World a moveLeft w@(World [] _ _) = w moveLeft (World as b cs) = World (init as) (last as) (b:cs) -- returns a world in which the Wumpus has either 1) moved one tile to -- the right or 2) stayed in the same place if the Wumpus could not move -- to the right. moveRight :: World a -> World a moveRight w@(World _ _ []) = w moveRight (World as b cs) = World (as ++ [b]) (head cs) (tail cs) initWorld = World [Dirty, Clean, Dirty] Dirty [Clean, Dirty, Pit] -- cleans the current tile cleanTile :: Tile -> Tile cleanTile Dirty = Clean cleanTile t = t Thanks!

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  • Do you know of a C dictionary that supports COW transactions?

    - by Tim Post
    I'm looking for a key - value dictionary library written in C that supports a theoretically unlimited number of cheap transactions. I'd like to have one dictionary in memory, with hundreds of threads starting transactions, possibly modifying the dictionary, ending (completing) the transaction or potentially aborting the transaction. Only 50% of the time will these threads actually modify the dictionary. Most dictionary transaction implementations that I've seen copy always, instead of copying on write, whenever a transaction is started. Given the expected size ( 1GB) of the dictionary, I'm hoping to find something that COWs only when something is actually changed during a transaction. I'm also hoping for something that is packaged by most major GNU/Linux distributions. Any suggestions or links are very much appreciated.

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  • latex table reference

    - by Tim
    Hi, I wrote a long table with a label in a tex file and \input it into my main tex file. The reference in the main tex file to the table, however, does not show the numbering of the table but the one of the next table that are written directly in the main tex file. All long tables that are written directly in the main tex file have correct references. How to fix my problem? Must the label be defined in the same tex file as its reference? Thanks and regards! The label is \label{tab:yy}, and the reference is \ref{tab:yy}, and every table has a distinct label.

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  • VB.NET logical expression evaluator

    - by Tim
    I need to test a logical expression held in a string to see if it evaluate to TRUE or FALSE.(the strig is built dynamically) For example the resulting string may contain "'dog'<'cat' OR (14 AND 4<6)". There are no variables in the string, it will logically evaluate. It will only contain simple operators = < < = <= and AND , OR and Open and Close Brackets, string constants and numbers. (converted to correct syntax && || etc.) I currently acheive this by creating a jscipt function and compiling it into a .dll. I then reference the .dll in my VB.NET project. class ExpressionEvaluator { function Evaluate(Expression : String) { return eval(Expression); } } Is there a simpler method using built in .NET functions or Lamdba expressions.

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  • Tutorials for an experienced C# user to learn C++

    - by Tim R.
    Are there any good resources for learning C++ that a C# user could use, which don't require knowledge of C? I have quite a good knowledge of C# via courses in my University's game development program (in a 300 level course right now) but now I need to use C++ for a project. I would use a beginner tutorial but they are so hard for me to follow and learn the basic syntax because they start so slowly. I found a few of tutorials for switching from C++ to C#, but none in the other direction. I do have a little bit of Objective C practice from iPhone programming as well.

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  • Get dimensions for dataset matlab, Size Function

    - by Tim
    Hello I have been trying to display the dimensions of a dataset, below is the following matlab code that i used...but it gives me the wrong output....i'e number of rows and columns values are wrong....any help regarding this issue would be highly appreciated [file_input,pathname] = uigetfile( ... {'*.txt', 'Text (*.txt)'; ... '*.xls', 'Excel (*.xls)'; ... '*.*', 'All Files (*.*)'}, ... 'Select files'); [pathstr, name, ext, versn] = fileparts(file_input) r = size(name,1); c = size(name,2); disp(r) disp(c)

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  • Load DOM before css?

    - by Tim
    My jQuery code sets the height of an element to 0px as soon as the page loads, then animates it to 500px. In my CSS, this element is already set to 500px (in case anyone has javascript turned off). I tried 'DEFER' on the tag where I link to the stylesheet so that the CSS loads in last of all, but that causes a blank white page to show up between navigating through pages - which I don't want, because I lose the smooth page transition effects that I am after. Is there a way that I can set the height in the CSS to 0px and IF javascript IS turned off, have it set to 500px, perhaps? :\ That's what I'm after, in effect. Any ideas? Many thanks for your help.

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  • How to focus a control in an MDIParent when all child windows have closed?

    - by Tim Gradwell
    I have a control in my parent mdi form which I wish to be given the focus if all mdi children have closed. I've tried hooking into the child form's FormClosed event and setting the focus from there but when I test it, my control is not left with focus when I close the mdi child. Can anyone tell me what I'm missing? In the sample below, "first focus" gets hit and does its job correctly (if I comment out the first focus line, my tree does not get focus on startup, so it must be doing its job, right?) Unfortunately, even though "second focus" gets hit, my tree does not end up with the focus when I close the child window. Sample using System; using System.Windows.Forms; namespace mdiFocus { class ParentForm : Form { public ParentForm() { IsMdiContainer = true; tree = new TreeView(); tree.Nodes.Add("SomeNode"); tree.Dock = DockStyle.Left; Controls.Add(tree); } protected override void OnShown(EventArgs e) { Form child = new Form(); child.MdiParent = this; child.Show(); child.FormClosed += new FormClosedEventHandler(child_FormClosed); tree.Focus(); // first focus works ok } void child_FormClosed(object sender, FormClosedEventArgs e) { tree.Focus(); // second focus doesn't seem to work, even though it is hit :( } TreeView tree; } static class Program { [STAThread] static void Main() { Application.Run(new ParentForm()); } } }

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  • Switching to FormViewMode.Edit is very slow

    - by Tim
    When i switch an ASP.Net Formview from readonly mode to edit mode it takes more than 6 seconds(from edit to readonly takes a split second). I have no idea whats the reason for it. The EditItemTemplate contains a lot of controls(table,textboxes,dropdownlists) but in fact not more than the ItemTemplate has. Yet i have even commented out the complete FormView.DataBound where the controls are data bounded but without significant change. My ASP.Net Web Apllication is using Ajax and the Formview is completely nested in an UpdatePanel. Any suggestions or assumptions for this behaviour?

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  • How to choose between UUIDs, autoincrement/sequence keys and sequence tables for database primary keys?

    - by Tim
    I'm looking at the pros and cons of these three primary methods of coming up with primary keys for database rows. So assuming I am using a database that supports more than one of these methods, is there a simple heuristic to determine what the best option would be for me? How do considerations such a distributed/multiple masters, performance requirements, ORM use, security and testing have on the choice? Any unexpected drawbacks that one might run into?

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  • Passing values into regex match function

    - by Tim
    In python (it's a Django filter), I'm doing this: lReturn = re.sub(r'\[usecase:([ \w]+)]', r'EXTEND WITH <a href="/usecase/%s/\1/">\1</a>' % pCurrentProjectName, lReturn) I'd like to use a function instead of a string (so I can check that the usercase is a valid name), so it would change to this: def _match_function(matchobj): lMatch = matchobj.group(1) return "EXTEND WITH <a href='/usecase/%s/%s/'>%s</a>" % (pCurrentProjectName, lMatch, lMatch) lReturn = re.sub(r'\[usecase:([ \w]+)]', _match_function, lReturn) How do I get pCurrentProjectName into the _match_function() function?

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  • How to refactor models without breaking WPF views?

    - by Tim Murphy
    I've just started learning WPF and like the power of databinding it presents; that is ignoring the complexity and confusion for a noob. My concern is how do you safely refactor your models/viewmodels without breaking the views that use them? Take the following snippet of a view for example: <Grid> <ListView ItemsSource="{Binding Contacts}"> <ListView.View> <GridView> <GridViewColumn Header="First Name" DisplayMemberBinding="{Binding Path=FirstName}"/> <GridViewColumn Header="Last Name" DisplayMemberBinding="{Binding Path=FirstName}"/> <GridViewColumn Header="DOB" DisplayMemberBinding="{Binding Path=DateOfBirth}"/> <GridViewColumn Header="# Pets" DisplayMemberBinding="{Binding Path=NumberOfPets}"/> <GridViewColumn Header="Male" DisplayMemberBinding="{Binding Path=IsMale}"/> </GridView> </ListView.View> </ListView> </Grid> The list is bound to the Contacts property, IList(Of Contact), of the windows DataSource and each of the properties for a Contact is bound to a GridViewColumn. Now if I change the name of the NumberOfPets property in the Contact model to PetCount the view will break. How do I prevent the view breaking?

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  • Trying to match what is before /../ but after / with regular expressions

    - by tim
    I am trying to match what is before /../ but after / with regular expressions, but i want it to look back and stop at the first / I feel like I am close but it just looks at the first slash and then takes everything after it like... input is this: this/is/a/./path/that/../includes/face/./stuff/../hat and my regular expression is #\/(.*)\.\.\/# matching /is/a/./path/that/../includes/face/./stuff/../ instead of just that/../ and stuff/../ how can i adapt what i'm doing to work?

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  • Posting form using javascript and json with nested objects

    - by Tim
    I have an html form that has the following structure: <input type="text" name="title" /> <input type="text" name="persons[0].name" /> <input type="text" name="persons[0].color" /> <input type="text" name="persons[1].name" /> <input type="text" name="persons[1].color" /> I would like to serialize this into the following json: { "title":"titlecontent", "persons":[ { "name":"person0name", "color":"red" }, { "name":"person1name", "color":"blue" } ] } Notice that the number of persons can vary from case to case. The structure of the html form can change, but the structure of the submitted json can't. How is this done the easiest?

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  • How do I correlate build configurations in dependant vcproj files with different names?

    - by Tim
    I have a solution file that requires a third party library (open source). The containing solution uses the typical configuration names of "Debug" and "release". The 3rd party one has debug and release configs for both DLL and static libs - their names are not "Debug" and "Release". How do I tell the solution to build the dependency first and how do I correlate which config to the dependant config? i.e. MyProject:Debug should build either 3rdParty:debug_shared or 3rdParty:debug_static

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  • Oracle: TABLE ACCESS FULL with Primary key?

    - by tim
    There is a table: CREATE TABLE temp ( IDR decimal(9) NOT NULL, IDS decimal(9) NOT NULL, DT date NOT NULL, VAL decimal(10) NOT NULL, AFFID decimal(9), CONSTRAINT PKtemp PRIMARY KEY (IDR,IDS,DT) ) ; SQL>explain plan for select * from temp; Explained. SQL> select plan_table_output from table(dbms_xplan.display('plan_table',null,'serial')); PLAN_TABLE_OUTPUT -------------------------------------------------------------------------------- --------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| --------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 61 | 2 (0)| | 1 | TABLE ACCESS FULL| TEMP | 1 | 61 | 2 (0)| --------------------------------------------------------------- Note ----- - 'PLAN_TABLE' is old version 11 rows selected. SQL server 2008 shows in the same situation Clustered index scan. What is the reason?

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  • JavaScript pack("d") - binary strings

    - by Tim Whitlock
    I'm trying to replicate the Perl and PHP style pack and unpack functions in JavaScript. Unsigned integers were easy enough, so my pack('n') and pack('N') are ok. But my lack of a computer science background is a hurdle now and I don't know where to start with pack('d') for packing JavaScript's standard floating point. Is there a JavaScript library for this out there? If not, is there a good resource where I can learn how to do this? I am fine with bitwise and binary level operations in JS, I just don't know where to start with the logic. Thanks.

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  • Is there a C++ cross platform key/value API or library for C++?

    - by Tim
    We want to persist some user settings int he GUI part of our code. I used to do Win32 programming exclusively and the typical way this was done was with registry settings. I assume that this should be done with configuration files, but was wondering if there was a library or cross platform wrapper that made key/value pair persistence very easy.

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  • For-Loop and LINQ's deferred execution don't play well together

    - by Tim Schmelter
    The title suggests that i've already an idea what's going on, but i cannot explain it. I've tried to order a List<string[]> dynamically by each "column", beginning with the first and ending with the minimum Length of all arrays. So in this sample it is 2, because the last string[] has only two elements: List<string[]> someValues = new List<string[]>(); someValues.Add(new[] { "c", "3", "b" }); someValues.Add(new[] { "a", "1", "d" }); someValues.Add(new[] { "d", "4", "a" }); someValues.Add(new[] { "b", "2" }); Now i've tried to order all by the first and second column. I could do it statically in this way: someValues = someValues .OrderBy(t => t[0]) .ThenBy(t => t[1]) .ToList(); But if i don't know the number of "columns" i could use this loop(that's what I thought): int minDim = someValues.Min(t => t.GetLength(0)); // 2 IOrderedEnumerable<string[]> orderedValues = someValues.OrderBy(t => t[0]); for (int i = 1; i < minDim; i++) { orderedValues = orderedValues.ThenBy(t => t[i]); } someValues = orderedValues.ToList(); // IndexOutOfRangeException But that doesn't work, it fails with an IndexOutOfRangeException at the last line. The debugger tells me that i is 2 at that time, so the for-loop condition seems to be ignored, i is already == minDim. Why is that so?

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  • What's the best way to handle layout issues with multi-language support in WPF/XAML?

    - by Tim
    I'm creating a standalone WPF app with multi-language support. I've found some great resources (mostly on SO) on how to store and access the strings as needed. This part is pretty straightforward and doable, but I'm fuzzy on how to take care of screen layout issues. I'm using some custom images to skin up my app for buttons, etc. For instance, here's a button with some text within: <Button Canvas.Left="33" Canvas.Top="484" Style="{StaticResource SmallButtonBase}"> <TextBlock FontSize="20" FontWeight="Bold" TextAlignment="Center" FontFamily="Helvetica"> Enter </TextBlock> </Button> Now here is the same button with text from another language: <Button Canvas.Left="33" Canvas.Top="484" Style="{StaticResource SmallButtonBase}"> <TextBlock FontSize="20" FontWeight="Bold" TextAlignment="Center" FontFamily="Helvetica"> Enterenschtein </TextBlock> </Button> So my question is: What is a good method to prevent this "overflow" situation. I'd like to have XAML take care of any font resizing or indenting that is needed automatically so that I don't have to tweak the UI for each language I'm supporting. Any insight is appreciated!

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  • Will an optimizing compiler remove calls to a method whose result will be multiplied by zero?

    - by Tim R.
    Suppose you have a computationally expensive method, Compute(p), which returns some float, and another method, Falloff(p), which returns another float from zero to one. If you compute Falloff(p) * Compute(p), will Compute(p) still run when Falloff(p) returns zero? Or would you need to write a special case to prevent Compute(p) from running unnecessarily? Theoretically, an optimizing compiler could determine that omitting Compute when Falloff returns zero would have no effect on the program. However, this is kind of hard to test, since if you have Compute output some debug data to determine whether it is running, the compiler would know not to omit it because of that debug info, resulting in sort of a Schrodinger's cat situation. I know the safe solution to this problem is just to add the special case, but I'm just curious.

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