Search Results

Search found 10522 results on 421 pages for 'self evaluation'.

Page 24/421 | < Previous Page | 20 21 22 23 24 25 26 27 28 29 30 31  | Next Page >

• Design suggestion for expression tree evaluation with time-series data

  - by Lirik

  I have a (C#) genetic program that uses financial time-series data and it's currently working but I want to re-design the architecture to be more robust. My main goals are: sequentially present the time-series data to the expression trees. allow expression trees to access previous data rows when needed. to optimize performance of the data access while evaluating the expression trees. keep a common interface so various types of data can be used. Here are the possible approaches I've thought about: I can evaluate the expression tree by passing in a data row into the root node and let each child node use the same data row. I can evaluate the expression tree by passing in the data row index and letting each node get the data row from a shared DataSet (currently I'm passing the row index and going to multiple synchronized arrays to get the data). Hybrid: an immutable data set is accessible by all of the expression trees and each expression tree is evaluated by passing in a data row. The benefit of the first approach is that the data row is being passed into the expression tree and there is no further query done on the data set (which should increase performance in a multithreaded environment). The drawback is that the expression tree does not have access to the rest of the data (in case some of the functions need to do calculations using previous data rows). The benefit of the second approach is that the expression trees can access any data up to the latest data row, but unless I specify what that row is, I'll have to iterate through the rows and figure out which one is the last one. The benefit of the hybrid is that it should generally perform better and still provide access to the earlier data. It supports two basic "views" of data: the latest row and the previous rows. Do you guys know of any design patterns or do you have any tips that can help me build this type of system? Should I use a DataSet to hold and present the data, or are there more efficient ways to present rows of data while maintaining a simple interface? FYI: All of my code is written in C#.

  Read the article

• DTO and Self Tracking Entities pattern in the entity framework

  - by kathy

  Hello, In What scenario that I have to use DTO's pattern in the entity framework the and not the Self Tracking Entities pattern? Can I start with Self Tracking Entities because it's easier to develop and then add DTO's in the next Phase ??? As always, your advice is greatly appreciated...

  Read the article

• Lazy evaluation in Ruby

  - by fifigyuri

  I have a situation for Ruby, where an object is possibly necessary to be created, but it is not sure. And as the creation of the object might be costly I am not too eager creating it. I think this is a clear case for lazy loading. How can I define an object which is not created only when someone sends a message to it? The object would be created in a block. Is there a way for simple lazy loading/initialisation in Ruby? Are these things supported by some gems, which provide different solutions for various cases of lazy initialisation of objects? Thanks for your suggestions!

  Read the article

• Dymanic if statement evaluation problem with string comparison

  - by Mani

  I tried the example given in http://forums.sun.com/thread.jspa?threadID=780576&tstart=67605 to create if statement dynamically. But it is not working fine. Instead of using "age" variable as integer, i have used string in the below example. I am getting "fail" as answer instead of "success". Can anyone help me? / To change this template, choose Tools | Templates and open the template in the editor. / import java.lang.reflect.*; import bsh.Interpreter; public class Main { public static String d; public static void main(String args[]) { try { String age = "30"; String cond = "age==30"; Interpreter i = new Interpreter(); i.set("age", age); System.out.println(" sss" + i.get("age")); if((Boolean)i.eval(cond)) { System.out.println("success"); } else { System.out.println("fail"); } } catch (Throwable e) { System.err.println(e); } } } Thanks, Mani

  Read the article

• javascript variable evaluation in function

  - by lamerzpua

  I trying to use simile widget for own need but I'm stuck on such problem. I have loop for (i=0;i<15;i++){ Timeline.loadXML(function_that_return_url(), function(xml, url) { eventSource[i].loadXML(xml, url); }); } This code is for Timeline.loadXML: Timeline.loadXML = function(url, f) { var fError = function(statusText, status, xmlhttp) { alert("Failed to load data xml from " + url + "\n" + statusText); }; var fDone = function(xmlhttp) { var xml = xmlhttp.responseXML; if (!xml.documentElement && xmlhttp.responseStream) { xml.load(xmlhttp.responseStream); } f(xml, url); }; SimileAjax.XmlHttp.get(url, fError, fDone);}; When I open the page - my function function(xml, url) { eventSource[i].loadXML(xml, url); }); is passed to loadXML method which use it inside as f(xml, url); Problem is that i variable is not parsed as number and I receive message that eventSource[...] is not declared. How I can evaluate i values before it will be posted as argument for the method LoadXML ?

  Read the article

• Partial Evaluation of ConstantExpression in ExpressionTreeVisitor

  - by Andrew Theken

  Hi all, I am not an Expression Tree master by any stretch of the imagination, what I have is code that looks like this: int external = 10; using(var session = new Session()) { session.Add(new Product { Name = "test1", Price = 20 }); session.Add(new Product {Name = "test", Price = 10}); var product = session.Products.Where(p => p.Price == external).FirstOrDefault(); Assert.Equal(10, product.Price); } Session implements all the IQueryProvider, IQueryable interfaces you'd come to expect from a LINQ Provider. When I execute the query, everything goes to plan until I read the ConstantExpression for "external", at which point, I am at a loss as to how to move forward because: //constant is ConstantExpression for "external" on the right side of the "p.Price == external" expression above. var t = constant.GetType(); //evaluates to class called "<>c__DisplayClass2" - with a member named "external" that has the value 10. The question is basically.. How can I just access the value of the member "external" - is there a way to accomplish this without using reflection? or am I cooked? What am I missing?

  Read the article

• PyQt Drag and Drop - Nothing happens

  - by Umang

  Hi, I'm trying to get drop a file onto a Window (I've tried the same thing with a QListWidget without success there too) test.py: #! /usr/bin/python # Test from PyQt4 import QtCore, QtGui import sys from qt_test import Ui_MainWindow class MyForm(QtGui.QMainWindow, Ui_MainWindow): def __init__(self, parent=None): QtGui.QWidget.__init__(self, parent) self.setupUi(self) self.__class__.dragEnterEvent = self.DragEnterEvent self.__class__.dragMoveEvent = self.DragEnterEvent self.__class__.dropEvent = self.drop self.setAcceptDrops(True) print "Initialized" self.show() def DragEnterEvent(self, event): event.accept() def drop(self, event): link=event.mimeData().text() print link def main(): app = QtGui.QApplication(sys.argv) mw = MyForm() sys.exit(app.exec_()) if __name__== "__main__": main() And here's qt_test.py # -*- coding: utf-8 -*- # Form implementation generated from reading ui file 'untitled.ui' # # Created: Thu May 20 12:23:19 2010 # by: PyQt4 UI code generator 4.6 # # WARNING! All changes made in this file will be lost! from PyQt4 import QtCore, QtGui class Ui_MainWindow(object): def setupUi(self, MainWindow): MainWindow.setObjectName("MainWindow") MainWindow.resize(800, 600) MainWindow.setAcceptDrops(True) self.centralwidget = QtGui.QWidget(MainWindow) self.centralwidget.setObjectName("centralwidget") MainWindow.setCentralWidget(self.centralwidget) self.retranslateUi(MainWindow) QtCore.QMetaObject.connectSlotsByName(MainWindow) def retranslateUi(self, MainWindow): MainWindow.setWindowTitle(QtGui.QApplication.translate("MainWindow", "MainWindow", None, QtGui.QApplication.UnicodeUTF8)) I've read this email and I've followed everything said there. I still don't get any output except "Initialized" and the drag doesn't seem to get accepted (both for files from a file manager and plain text dragged from a text editor). Do you know what I'm doing wrong? Thanks!

  Read the article

• Rails class << self

  - by xpepermint

  Hey. I would like to understand what "class << self" stands for in the next example. module Utility class Options #:nodoc: class << self def parse(args) end end end end Thx!

  Read the article

• Copy **kwargs to self?

  - by Mark

  Given class ValidationRule: def __init__(self, **kwargs): # code here Is there a way that I can define __init__ such that if I were to initialize the class with something like ValidationRule(other='email') then self.other would be "added" to class without having to explicitly name every possible kwarg?

  Read the article

• Postgresql: Implicit lock acquisition from foreign-key constraint evaluation

  - by fennec

  So, I'm being confused about foreign key constraint handling in Postgresql. (version 8.4.4, for what it's worth). We've got a couple of tables, mildly anonymized below: device: (id, blah, blah, blah, blah, blah x 50)… primary key on id whooooole bunch of other junk device_foo: (id, device_id, left, right) Foreign key (device_id) references device(id) on delete cascade; primary key on id btree index on 'left' and 'right' So I set out with two database windows to run some queries. db1> begin; lock table device in exclusive mode; db2> begin; update device_foo set left = left + 1; The db2 connection blocks. It seems odd to me that an update of the 'left' column on device_stuff should be affected by activity on the device table. But it is. In fact, if I go back to db1: db1> select * from device_stuff for update; *** deadlock occurs *** The pgsql log has the following: blah blah blah deadlock blah. CONTEXT: SQL statement "SELECT 1 FROM ONLY "public"."device" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF X: update device_foo set left = left + 1; I suppose I've got two issues: the first is that I don't understand the precise mechanism by which this sort of locking occurs. I have got a couple of useful queries to query pg_locks to see what sort of locks a statement invokes, but I haven't been able to observe this particular sort of locking when I run the update device_foo command in isolation. (Perhaps I'm doing something wrong, though.) I also can't find any documentation on the lock acquisition behavior of foreign-key constraint checks. All I have is a log message. Am I to infer from this that any change to a row will acquire an update lock on all the tables which it's foreign-keyed against? The second issue is that I'd like to find some way to make it not happen like that. I'm ending up with occasional deadlocks in the actual application. I'd like to be able to run big update statements that impact all rows on device_foo without acquiring a big lock on the device table. (There's a lot of access going on in the device table, and it's kind of an expensive lock to get.)

  Read the article

• python sax error "junk after document element"

  - by user293487

  Hi, I use python sax to parse xml file. The xml file is actually a combination of multiple xml files. It looks like as follows: <row name="abc" age="40" body="blalalala..." creationdate="03/10/10" /> <row name="bcd" age="50" body="blalalala..." creationdate="03/10/09" /> My python code is in the following. It show "junk after document element" error. Any good idea to solve this problem. Thanks. from xml.sax.handler import ContentHandler from xml.sax import make_parser,SAXException import sys class PostHandler (ContentHandler): def __init__(self): self.find = 0 self.buffer = '' self.mapping={} def startElement(self,name,attrs): if name == 'row': self.find = 1 self.body = attrs["body"] print attrs["body"] def character(self,data): if self.find==1: self.buffer+=data def endElement(self,name): if self.find == 1: self.mapping[self.body] = self.buffer print self.mapping parser = make_parser() handler = PostHandler() parser.setContentHandler(handler) try: parser.parse(open("2.xml")) except SAXException:

  Read the article

• logical operators evaluation in return statemnet in python

  - by table

  hi, how does this execute: **def f(x): return x0 and (x%2)+f(x/2) or 0** x is an array ,for instanse,[1, 1, 1, 3] thank u

  Read the article

• jquery ajax post and response evaluation

  - by Rami

  Hello people, i am relatively new to javascript and jquery in particular, so please bear with me, i am trying to loop through multiple s and then serialize() the data with jquery and post it using ajax to my page, this's happening alright, and the data is posted, and my php script echos 1 and everything is taken care off, but for some strange reason, the following code is not working, specially the "success" variable, it's not increasing at all! would you please help me? $('.submitB').click(function(){ var success = 0; var times = 0; var alertText; $('.input').each(function(){ times++; var serializedForms = $(this).serialize(); $.post('<?=$this->config->site_url()?>crud/additem/forms', serializedForms ,function(data){ if (data) { success++; } }); }); if (times) { alertText = "?? ????? " + success + " ???? ?? ??? " + times + " ?????."; alert(alertText); } }) the Arabic text just says "success + Entries from + times + were entered successfully".. thank you in advance.

  Read the article

• How to set the size of a wx.aui.AuiManager Pane that is centered?

  - by aF

  Hello, I have three panes with the InfoPane center option. I want to know how to set their size. Using this code: import wx import wx.aui class MyFrame(wx.Frame): def __init__(self, parent, id=-1, title='wx.aui Test', pos=wx.DefaultPosition, size=(800, 600), style=wx.DEFAULT_FRAME_STYLE): wx.Frame.__init__(self, parent, id, title, pos, size, style) self._mgr = wx.aui.AuiManager(self) # create several text controls text1 = wx.TextCtrl(self, -1, 'Pane 1 - sample text', wx.DefaultPosition, wx.Size(200,150), wx.NO_BORDER | wx.TE_MULTILINE) text2 = wx.TextCtrl(self, -1, 'Pane 2 - sample text', wx.DefaultPosition, wx.Size(200,150), wx.NO_BORDER | wx.TE_MULTILINE) text3 = wx.TextCtrl(self, -1, 'Main content window', wx.DefaultPosition, wx.Size(200,150), wx.NO_BORDER | wx.TE_MULTILINE) # add the panes to the manager self._mgr.AddPane(text1, wx.CENTER) self._mgr.AddPane(text2, wx.CENTER) self._mgr.AddPane(text3, wx.CENTER) # tell the manager to 'commit' all the changes just made self._mgr.Update() self.Bind(wx.EVT_CLOSE, self.OnClose) def OnClose(self, event): # deinitialize the frame manager self._mgr.UnInit() # delete the frame self.Destroy() app = wx.App() frame = MyFrame(None) frame.Show() app.MainLoop() I want to know what is called when we change the size of the panes. If you tell me that, I can do the rest by myself :)

  Read the article

• Python evaluation order

  - by d.m

  Here's the code, I don't quite understand, how does it work. Could anyone tell, is that an expected behavior? $ipython In [1]: 1 in [1] == True Out[1]: False In [2]: (1 in [1]) == True Out[2]: True In [3]: 1 in ([1] == True) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/dmedvinsky/projects/condo/condo/<ipython console> in <module>() TypeError: argument of type 'bool' is not iterable In [4]: from sys import version_info In [5]: version_info Out[5]: (2, 6, 4, 'final', 0)

  Read the article

• wxpython: Updating a dict or other appropriate data type from wx.lib.sheet.CSheet object

  - by bvmou

  If I have a notebook with three spreadsheet widgets, what is the best way to have changes to the spreadsheet update a dictionary (or maybe an sqlite file?). Do all wx grid objects come with a built in dictionary related to the SetNumberRows and SetNumberCols? Basically I am looking for guidance on how to work with the user-input data from a spreadsheet widget, as in this example adapted from the tutorial on python.org: class ExSheet(wx.lib.sheet.CSheet): def __init__(self, parent): sheet.CSheet.__init__(self, parent) self.SetLabelBackgroundColour('#CCFF66') self.SetNumberRows(50) self.SetNumberCols(50) class Notebook(wx.Frame): def __init__(self, parent, id, title): wx.Frame.__init__(self, parent, id, title) nb = wx.Notebook(self, -1, style=wx.NB_BOTTOM) self.sheet1 = ExSheet(nb) self.sheet2 = ExSheet(nb) self.sheet3 = ExSheet(nb) nb.AddPage(self.sheet1, "Sheet1") nb.AddPage(self.sheet2, "Sheet2") nb.AddPage(self.sheet3, "Sheet3") self.sheet1.SetFocus() self.StatusBar()

  Read the article

• 'int' object is not callable

  - by Oscar Reyes

  I'm trying to define a simply Fraction class And I'm getting this error: python fraction.py Traceback (most recent call last): File "fraction.py", line 20, in <module> f.numerator(2) TypeError: 'int' object is not callable The code follows: class Fraction(object): def __init__( self, n=0, d=0 ): self.numerator = n self.denominator = d def get_numerator(self): return self.numerator def get_denominator(self): return self.denominator def numerator(self, n): self.numerator = n def denominator( self, d ): self.denominator = d def prints( self ): print "%d/%d" %(self.numerator, self.denominator) if __name__ == "__main__": f = Fraction() f.numerator(2) f.denominator(5) f.prints() I thought it was because I had numerator(self) and numerator(self, n) but now I know Python doesn't have method overloading ( function overloading ) so I renamed to get_numerator but that's not the problems. What could it be?

  Read the article

• simple php Dollar $ evaluation in string questions

  - by Mirage

  I have always been confused that .e,g in php i have sql statement $qry = "select * from table where id = $id"; now can i insert "$" directly inside the quotes or i have to use $qry = "select * from table where id =".$id." "; or $qry = 'select * from table where id = $id'; or $qry = 'select * from table where id = '$id''; Which is correct

  Read the article

• Clojure evaluation without SLIME

  - by Denis

  Hi, I'm a starter with Emacs (but quite experienced Vim user) and trying to play with Emacs+Clojure combination. Maybe my setup will be unusual for Emacs world, as I'm not using SLIME/swank-clojure, but Emacs + eshell with running clojure REPL in it, mostly due simplicity (or probably because SLIME quite scares me off :D). So, maybe there is a Emacs guru that can help me here: does exists any shortcut (or maybe some elisp sample) to copy/paste code chunks (sexps) from editing buffer to eshell (and possibly execute it)? Thanks.

  Read the article

• Connect 4 with neural network: evaluation of draft + further steps

  - by user89818

  I would like to build a Connect 4 engine which works using an artificial neural network - just because I'm fascinated by ANNs. I'be created the following draft of the ANN structure. Would it work? And are these connections right (even the cross ones)? Could you help me to draft up an UML class diagram for this ANN? I want to give the board representation to the ANN as its input. And the output should be the move to chose. The learning should later be done using backpropagation and the sigmoid function should be applied. The engine will play against human players. And depending on the result of the game, the weights should be adjusted then.

  Read the article

• add a decorate function to a class

  - by wiso

  I have a decorated function (simplified version): class Memoize: def __init__(self, function): self.function = function self.memoized = {} def __call__(self, *args, **kwds): hash = args try: return self.memoized[hash] except KeyError: self.memoized[hash] = self.function(*args) return self.memoized[hash] @Memoize def _DrawPlot(self, options): do something... now I want to add this method to a pre-esisting class. ROOT.TChain.DrawPlot = _DrawPlot when I call this method: chain = TChain() chain.DrawPlot(opts) I got: self.memoized[hash] = self.function(*args) TypeError: _DrawPlot() takes exactly 2 arguments (1 given) why doesn't it propagate self?

  Read the article

• std::conditional compile-time branch evaluation

  - by cmannett85

  Compiling this: template < class T, class Y, class ...Args > struct isSame { static constexpr bool value = std::conditional< sizeof...( Args ), typename std::conditional< std::is_same< T, Y >::value, isSame< Y, Args... >, // Error! std::false_type >::type, std::is_same< T, Y > >::type::value; }; int main() { qDebug() << isSame< double, int >::value; return EXIT_SUCCESS; } Gives me this compiler error: error: wrong number of template arguments (1, should be 2 or more) The issue is that isSame< double, int > has an empty Args parameter pack, so isSame< Y, Args... > effectively becomes isSame< Y > which does not match the signature. But my question is: Why is that branch being evaluated at all? sizeof...( Args ) is false, so the inner std:conditional should not be evaluated. This isn't a runtime piece of code, the compiler knows that sizeof..( Args ) will never be true with the given template types. If you're curious, it's supposed to be a variadic version of std::is_same, not that it works...

  Read the article

• JSTL expression evaluation from a string

  - by Venkatesh

  Is it possible to evaluate a String as EL expression in JSP and get value from it? I need an expression like ${model.${fieldPath}} where fieldPath will contain the required object path from a nested object model. I can get the actual field path by using but I am not sure how to evaluate a string and get the value from it Any help regarding this would be highly appreciated.

  Read the article

• WxPython multiple grid instances

  - by randomPythonHacker

  Does anybody know how I can get multiple instances of the same grid to display on one frame? Whenever I create more than 1 instance of the same object, the display of the original grid widget completely collapses and I'm left unable to do anything with it. For reference, here's the code: import wx import wx.grid as gridlib class levelGrid(gridlib.Grid): def __init__(self, parent, rows, columns): gridlib.Grid.__init__(self, parent, -1) self.moveTo = None self.CreateGrid(rows, columns) self.SetDefaultColSize(32) self.SetDefaultRowSize(32) self.SetColLabelSize(0) self.SetRowLabelSize(0) self.SetDefaultCellBackgroundColour(wx.BLACK) self.EnableDragGridSize(False) class mainFrame(wx.Frame): def __init__(self, parent, id, title): wx.Frame.__init__(self, parent, id, title, size=(768, 576)) editor = levelGrid(self, 25, 25) panel1 = wx.Panel(editor, -1) #vbox = wx.BoxSizer(wx.VERTICAL) #vbox.Add(editor, 1, wx.EXPAND | wx.ALL, 5) #selector = levelGrid(self, 1, 25) #vbox.Add(selector, 1, wx.EXPAND |wx.BOTTOM, 5) self.Centre() self.Show(True) app = wx.App() mainFrame(None, -1, "SLAE") app.MainLoop()

  Read the article

• template files evaluation in python

  - by saminny

  I am trying to use python for translating a set of templates to a set of configuration files based on values taken from a main configuration file. However, I am having certain issues. Consider the following example of a template file. file1.cfg.template %(CLIENT1)s %(HOST1)s %(PORT1)d C %(COMPID1)s %(CLIENT2)s %(HOST2)s %(PORT2)d C %(COMPID2)s This file contains an entry for each client. There are hundreds of config files like this and I don't want to have logic for each type of config file. Python should do the replacements and generate config files automatically given a set of global values read from a main xml config file. However, in the above example, if CLIENT2 does not exist, how do I delete that line? I expect Python would generate the config file using something like this: os.open("file1.cfg.template").read() % myhash where myhash is hash of configuration parameters from the main config file which may not contain CLIENT2 at all. In the case it does not contain CLIENT2, I want that line to disappear from the file. Is it possible to insert some 'IF' block in the file and have python evaluate it? Thanks for your help. Any suggestions most welcome.

  Read the article

< Previous Page | 20 21 22 23 24 25 26 27 28 29 30 31  | Next Page >