Search Results

Search found 15563 results on 623 pages for 'django model'.

Page 279/623 | < Previous Page | 275 276 277 278 279 280 281 282 283 284 285 286  | Next Page >

  • No more memory available in Mathematica, Fit the parameters of system of differential equation

    - by user1058051
    I encountered a memory problem in Mathematica, when I tried to process my experimental data. It's a system of two differential equations and I need to find most suitable parameters. Unfortunately I am not a Pro in Mathematica, so the program used a lot of memory, when the parameter epsilon is more than 0.4. When it less than 0.4, the program work properly. The command 'historylength = 0' and attempts to reduce the Accuracy Goal and WorkingPrecision didn`t help. I can't use ' clear Cache ', because there isnt a circle. I'm trying to understand what mistakes I made, and how I may limit the memory usage. I have already bought extra-RAM, now its 4GB, and now I haven't free memory-slots in motherboard Remove["Global`*"]; T=13200; L = 0.085; e = 0.41; v = 0.000557197; q = 0.1618; C0 = 0.0256; R = 0.00075; data = {{L,600,0.141124587},{L,1200,0.254134509},{L,1800,0.342888644}, {L,2400,0.424476295},{L,3600,0.562844542},{L,4800,0.657111356}, {L,6000,0.75137817},{L,7200,0.815876516},{L,8430,0.879823594}, {L,9000,0.900771775},{L,13200,1}}; model[(De_)?NumberQ, (Kf_)?NumberQ, (Y_)?NumberQ] := model[De, Kf, Y] = yeld /.Last[Last[ NDSolve[{ v (Ci^(1,0))[z,t]+(Ci^(0,1))[z,t]== -((3 (1-e) Kf (Ci[z,t]-C0))/ (R e (1-(R Kf (1-R/r[z,t]))/De))), (r^(0,1))[z,t]== (R^2 Kf (Ci[z,t]-C0))/ (q r[z,t]^2 (1-(R Kf (1-R/r[z,t]))/De)), (yeld^(0,1))[z,t]== Y*(v e Ci[z,t])/(L q (1-e)), r[z,0]==R, Ci[z,0]==0, Ci[0,t]==0, yeld[z,0]==0}, {r[z,t],Ci[z,t],yeld},{z,0,L},{t,0,T}]]] fit = FindFit[data, {model[De, Kf, Y][z, t], {Y > 0.97, Y < 1.03, Kf > 10^-6, Kf < 10^-4, De > 10^-13, De < 10^-9}}, {{De,7*10^-13}, {Kf, 10^-5}, {Y, 1}}, {z, t}, Method -> NMinimize] data = {{600,0.141124587},{1200,0.254134509},{1800,0.342888644}, {2400,0.424476295},{3600,0.562844542},{4800,0.657111356}, {6000,0.75137817},{7200,0.815876516},{8430,0.879823594}, {9000,0.900771775},{13200,1}}; YYY = model[ De /. fit[[1]], Kf /. fit[[2]], Y /. fit[[3]]]; Show[Plot[Evaluate[YYY[L,t]],{t,0,T},PlotRange->All], ListPlot[data,PlotStyle->Directive[PointSize[Medium],Red]]] the link on the .nb file http://www.4shared.com/folder/249TSjlz/_online.html

    Read the article

  • Lithium: Run filter after find() to format output

    - by Housni
    I wanted to specify the output of a field from within my model so I added a date key to my $_schema: models/Tags.php <?php protected $_schema = array( 'id' => array('type' => 'integer', 'key' => 'primary'), 'title' => array('type' => 'string'), 'created' => array('type' => 'integer', 'date' => 'F jS, Y - g:i a'), 'modified' => array('type' => 'integer') ); ?> I store my time as an unsigned integer in the db (output of time()). I want my base model to format any field that has the date key for output. I thought the best place to do that would be right after a find: extensions/data/Model.php <?php static::applyFilter('find', function($self, $params, $chain) { $schema = $self::schema(); $entity = $chain->next($self, $params, $chain); foreach ($schema as $field => $options) { if (array_key_exists('date', $options)) { //format as a date $params['data'][$field] = $entity->formatDate($field, $options['date']); } } return $entity; }); public function formatdate($entity, $field, $format, $timezone = 'Asia/Colombo') { $dt = new \DateTime(); $tz = new \DateTimeZone($timezone); $dt->setTimestamp($entity->$field); $dt->setTimezone($tz); return $dt->format($format); } ?> This doesn't seem to be working. When I execute a find all, this filter seems to get hit twice. The first time, $entity contains a count() of the results and only on the second hit does it contain the Records object. What am I doing wrong? How do I alter this so that simply doing <?= $tag->created; ?> in my view will format the date the way I want? This, essentially, needs to be an 'after filter', of sorts. EDIT If I can find a way to access the current model entity object (not the full namespaced path, $self contains that), I can probably solve my problem.

    Read the article

  • Asp.Net MVC How to test that the view rendered

    - by Miau
    HI there I was wondering if there is a better way of testing that a view has rendered in MVC. I was thinking perhaps I should render the view to a string but perhaps there are simpler methods? Basically what I want to know if that the view for a given action has rendered without errors I m already testing the view model but I want to see that rendering the view giving a correct ViewData.Model works

    Read the article

  • Problem persisting inheritance tree

    - by alaiseca
    I have a problem trying to map an inheritance tree. A simplified version of my model is like this: @MappedSuperclass @Embeddable public class BaseEmbedded implements Serializable { @Column(name="BE_FIELD") private String beField; // Getters and setters follow } @MappedSuperclass @Embeddable public class DerivedEmbedded extends BaseEmbedded { @Column(name="DE_FIELD") private String deField; // Getters and setters follow } @MappedSuperclass public abstract class BaseClass implements Serializable { @Embedded protected BaseEmbedded embedded; public BaseClass() { this.embedded = new BaseEmbedded(); } // Getters and setters follow } @Entity @Table(name="MYTABLE") @Inheritance(strategy=InheritanceType.SINGLE_TABLE) @DiscriminatorColumn(name="TYPE", discriminatorType=DiscriminatorType.STRING) public class DerivedClass extends BaseClass { @Id @Column(name="ID", nullable=false) private Long id; @Column(name="TYPE", nullable=false, insertable=false, updatable=false) private String type; public DerivedClass() { this.embedded = new DerivedClass(); } // Getters and setters follow } @Entity @DiscriminatorValue("A") public class DerivedClassA extends DerivedClass { @Embeddable public static NestedClassA extends DerivedEmbedded { @Column(name="FIELD_CLASS_A") private String fieldClassA; } public DerivedClassA() { this.embedded = new NestedClassA(); } // Getters and setters follow } @Entity @DiscriminatorValue("B") public class DerivedClassB extends DerivedClass { @Embeddable public static NestedClassB extends DerivedEmbedded { @Column(name="FIELD_CLASS_B") private String fieldClassB; } public DerivedClassB() { this.embedded = new NestedClassB(); } // Getters and setters follow } At Java level, this model is working fine, and I believe is the appropriate one. My problem comes up when it's time to persist an object. At runtime, I can create an object which could be an instance of DerivedClass, DerivedClassA or DerivedClassB. As you can see, each one of the derived classes introduces a new field which only makes sense for that specific derived class. All the classes share the same physical table in the database. If I persist an object of type DerivedClass, I expect fields BE_FIELD, DE_FIELD, ID and TYPE to be persisted with their values and the remaining fields to be null. If I persist an object of type DerivedClass A, I expect those same fields plus the FIELD_CLASS_A field to be persisted with their values and field FIELD_CLASS_B to be null. Something equivalent for an object of type DerivedClassB. Since the @Embedded annotation is at the BaseClass only, Hibernate is only persisting the fields up to that level in the tree. I don't know how to tell Hibernate that I want to persist up to the appropriate level in the tree, depending on the actual type of the embedded property. I cannot have another @Embedded property in the subclasses since this would duplicate data that is already present in the superclass and would also break the Java model. I cannot declare the embedded property to be of a more specific type either, since it's only at runtime when the actual object is created and I don't have a single branch in the hierarchy. Is it possible to solve my problem? Or should I resignate myself to accept that there is no way to persist the Java model as it is? Any help will be greatly appreciated.

    Read the article

  • What can be inside a class that derive from OmniAuth?

    - by Richard77
    I have the following class class Identity < OmniAuth:: Identity:: Models:: ActiveRecord attr_accessible :email, :name, :password_digest, :password, :password_confirmation end I wonder if the above properties are the only ones allowed for a class that derive from a OmniAuth. I wish I could add some more like FirstName, LastName, age, gender, and so on. Do I need to create an other model for those properties or can I just add them to the Identity model? Thanks for helping.

    Read the article

  • Object Oriented vs Relational Databases

    - by Dan
    Objects oriented databases seem like a really cool idea to me, no need to worry about mapping your domain model to your database model, no messing around with sql or ORM tools. The way I understand it, relational DBs offer some advantages when there is massive amounts of data, and searching an indexing need to be done. To my mind 99% of websites are not massive, and enterprise issues never need to be thought about, so why arn't OO DBs more widely used?

    Read the article

  • Entity Framework equivalence for NHibernte SchemaExport

    - by jbandi
    Is there an equivalence in Entity Framework to NHibernate SchemaExport? Given I have a working Entity-Model, I would like to programmatically initialize a database. I would like to use this functionality in the setup of my integration tests. Creating the matching DDL for an Entity-Model would also suffice.

    Read the article

  • What's the correct way to instantiate an IRepository class from the Controller?

    - by GenericTypeTea
    I have the following project layout: MVC UI |...CustomerController (ICustomerRepository - how do I instantiate this?) Data Model |...ICustomerRepository DAL (Separate Data access layer, references Data Model to get the IxRepositories) |...CustomerRepository (inherits ICustomerRepository) What's the correct way to say ICustomerRepository repository = new CustomerRepository(); when the Controller has no visibility to the DAL project? Or am I doing this completely wrong?

    Read the article

  • Can an ActiveRecord before_save filter halt the save without halting the transaction?

    - by Michael Boutros
    Is there any way for a before_save filter to halt the entire save without halting the transaction? What I'm trying to do is have a "sample" version of my model that the user can interact with and save but the changes themselves are never actually saved. The following will halt the transaction and (naturally) return false when I call @model.update_attributes: before_filter :ignore_changes_if_sample def ignore_changes_if_sample if self.sample? return false end end Thanks!

    Read the article

  • Converting OpenGL coordinates to lower UIView (and UIImagePickerController)

    - by John Qualis
    I am new to OpenGL on the iPhone. I am developing an iPhone app similar to a barcode reader but with an extra OpenGL layer. The bottommost layer is UIImagePickerController, then I use UIView on top and draw a rectangle at certain coordinates on the iPhone screen. So far everything is OK. Then I am trying to draw an OpenGL 3-D model in that rectangle. I am able to load a 3-D model in the iPhone based on this code here - http://iphonedevelopment.blogspot.com/2008/12/start-of-wavefront-obj-file-loader.html I am not able to transform the coordinates of the rectangle into OpenGL coordinates. Appreciate any help. Do I need to use a matrix to translate the currentPosition of the 3-D model so it is drawn within myRect? The code is given below. -(void)setupView:(GLView*)view { const GLfloat zNear = 0.01, zFar = 1000.0, fieldOfView = 45.0; GLfloat size; glEnable(GL_DEPTH_TEST); glMatrixMode(GL_PROJECTION); size = zNear * tanf(DEGREES_TO_RADIANS(fieldOfView) / 2.0); CGRect rect = view.bounds; glFrustumf(-size, size, -size / (rect.size.width / rect.size.height), size / (rect.size.width / rect.size.height), zNear, zFar); glViewport(0, 0, rect.size.width, rect.size.height); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glClearColor(0.0f, 0.0f, 0.0f, 0.0f); NSString *path = [[NSBundle mainBundle] pathForResource:@"plane" ofType:@"obj"]; OpenGLWaveFrontObject *theObject = [[OpenGLWaveFrontObject alloc] initWithPath:path]; Vertex3D position; position.z = -8.0; position.y = 3.0; position.x = 2.0; theObject.currentPosition = position; self.plane = theObject; [theObject release]; } - (void)drawView:(GLView*)view; { static GLfloat rotation = 0.0; glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); glColor4f(0.0, 0.5, 1.0, 1.0); // the coordinates of the rectangle are // myRect.x, myRect.y, myRect.width, myRect.height // Do I need to use a matrix to translate the currentPosition of the // 3-D model so it is drawn within myRect? //glOrthof(-160.0f, 160.0f, -240.0f, 240.0f, -1.0f, 1.0f); [plane drawSelf]; }

    Read the article

  • rake does not returning anything

    - by CHID
    Hi, I jus created a rails application. I created a model using ruby script/generate model Article next i edited the my articles.rb file by adding these lines in self.up method def self.up create_table :articles do |t| t.string :title t.text :body t.string :published_at t.timestamps end end Now i ran rake db:migrate . But migrate does not work, it simply does no print anything. Anyone knows where i am going wrong?

    Read the article

  • Google App Engine Python Datastore

    - by python appengine
    Basically what Im trying to make is a data structure where it has the users name, id, and datejoined. Then i want a "sub-structure" where it has the users "text" and the date it was modified. and the user will have multiple instances of this text. class User(db.Model): ID = db.IntegerProperty() name = db.StringProperty() datejoined = db.DateTimeProperty(auto_now_add=True) class Content(db.Model): text = db.StringProperty() datemod= db.DateTimeProperty(auto_now_add = True) Is the code set up correctly?

    Read the article

  • How to do a back-reference on Google AppEngine?

    - by jCuga
    I'm trying to access an object that is linked to by a db.ReferenceProperty in Google app engine. Here's the model's code: class InquiryQuestion(db.Model): inquiry_ref = db.ReferenceProperty(reference_class=GiftInquiry, required=True, collection_name="inquiry_ref") And I am trying to access it in the following way: linkedObject = question.inquiry_ref and then linkedKey = linkedObject.key but it's not working. Can anyone please help?

    Read the article

  • Can't import clojure records

    - by Zubair
    I have created a record like this: (defrecord User [user-id email]) :but when I try to access it from another name-space I get the error: (User. "name" "email") java.lang.IllegalArgumentException: Unable to resolve classname: User It works when I do: (oe.model.modelcore.User. "name" "email") : I know I will need to import the Java class, but is there any way for clojure to do this automatically when I do: (use 'oe.model.modelcore :reload)

    Read the article

  • validates_associated not honoring :if

    - by James Ferguson
    I'm totally blocked on this. See this pastie for sample code: http://pastie.org/990040 The first test will fail. The user model validates an associated address model, but is only supposed to do it if a flag is true. In practice it does it all the time. What is going on?

    Read the article

  • How can I iterate through all of the Models in my rails app?

    - by James
    I would like to be able to iterate over and inspect all the models in my rails app. In pseudo-code it would look something like: rails_env.models.each do |model| associations = model.reflect_on_all_associations(:has_many) ... do some stuff end My question is how do I inspect my rails app to get a collection of the models (rails_env.models) ?

    Read the article

  • Trying to make models in Kohana, relations problem.

    - by Asaf
    I have a table of Hits, Articles and Categories Now, a Hit belongs_to an Article/Category (depends on where it was done). so I have a column on Hits table with the name 'parenttype' That tells me 'Article' or 'Category'. I wrote in the Hit model (extends ORM) protected $_belongs_to= array( 'page' => array('model'=> $this->parenttype) ); Now it complains about $this-parenttype not being expected?

    Read the article

  • Single entity with single view or two views in mvc3 vs2010?

    - by user2905798
    I have the following entity model public class Employee { public int Employee ID{get;set;} public string employeename{get;set;} public datetime employeeDOb{get;set;} public datetime? employeeDateOfJoin{get;set;} public string empFamilyname{get;set;} public datetime empFamilyDob{get;set;} } here I have to design a view for collecting employee information and employee family information. Since I am working on already available data, where in empFamilyDob was not mandatory. But now it is being made mandatory, the previous data doesn't contain EmpFamilyDob. So naturally I have added this new property EmpFamilyDob to the Model and made it required through DataAnnotations. Now there are two set of views to be developed. 1. A view which simply allows to collect the employee information without employee family information. i.e, empFamilyName and EmpFamilyDob.--This view is used by the Hr section to insert empplyee details Since the empFamilyname and EmpFamilyDob being now made mandatory, some other section will edit the data and update the EmpFamilyName and EmpFamilyDob as and when the information about employee family details are received. I have action controller for CreateNew and Edit Which is being generated by using the default model. There are two user actions being performed. 1.When the user clicks the Create new -- he will be able to update only the Employee information 2.As and when the other section receives the employee family details they update the familyname and family date of birth. i.e, EmployeeFamilyname and EmployeFamilyDob. While creating new record the uses should be able to update employee information only and while editing the information he should be able to update the employeefamily information. Since I have a single view with most of these fields as required and not allowing null , How can I achieve this in a sincle view? I have recorrected the model like this public class Employee { public int Employee ID{get;set;} public string employeename{get;set;} public datetime employeeDOb{get;set;} public datetime? employeeDateOfJoin{get;set;} public string empFamilyname{get;set;} public datetime? empFamilyDob{get;set;} } Now by default I hope the createnew action would insert null value for empFamilyname(string datatype) and empFamilyDob . In the Edit action the user should be made to enter empFamilyname and empFamilyDob(mandatory). As there is every chance that the user might edit other information about the employee(like employeeDob) I don't want to go for partial views. Can you help me out with some illustration. Thanks in advance

    Read the article

  • ruby on rails- nested attributes for 'has_one' relationship

    - by Kum
    Hello, I need some help concerning nested attributes in models with 'has_one' relationship. Model Survey has 1 question Model Question has 1 answer How do i build the 'answer' in the code below def new @survey = Survey.new @survey.build_question # build one question @survey.question.answer.build #this part is not working end Please can anybody tell me how to build the answer as the code "@survey.question.answer.build" is not correct. Many many thanks for your help

    Read the article

  • how do I instrospect appengine's datastore models?

    - by python for ever
    in order to dynamically create a form, i have to find the property types of a model's properties at runtime. appengine docs says that Model.properties() will return a dictionary of properties name and their class type. when i use this method in my code, only the name is returned and the classtype value is always empty.

    Read the article

< Previous Page | 275 276 277 278 279 280 281 282 283 284 285 286  | Next Page >