model

问题 I have built a linear regression i R. Now I wanna store the model and use it for scoring a new data set once a week. Someone that can help me with how to? How to save the model and how to import it and use it on an new dataset. 回答1: You can save the model in a file and load it when you need it. For example, you might have a line like this to train your model: the_model <- glm(my_formula, family=binomial(link='logit'),data=training_set) This model can be saved with: save(file="modelfile",the

问题 I am quite new to this. I am getting an issue with selection items and post back to tableview on specific index cell (reload). Scenario: I have two view controllers and both contains tableview. FirstViewController: I am already displaying data from webservice into Tableview but on different action types I have used didSelectRow function which shows to ListViewController for item selection. In FirstViewController main model is Unit. ListViewController: Simple list of data displaying in

问题 I am quite new to this. I am getting an issue with selection items and post back to tableview on specific index cell (reload). Scenario: I have two view controllers and both contains tableview. FirstViewController: I am already displaying data from webservice into Tableview but on different action types I have used didSelectRow function which shows to ListViewController for item selection. In FirstViewController main model is Unit. ListViewController: Simple list of data displaying in

问题 I have a Rails 3 application, say, with hotels, where hotels belong to parent areas. When a user hits the app (served by mongrel >> nginx), I want the domain name used in the request to decide what area of hotels to serve up (domain name >> area). To achieve this I can see two options: 1) Rewrite the URL with nginx, inserting the area id after the domain name (e.g. birminghamhotels.co.uk => proxy_pass http://myupstream/areas/3$request_uri). Benefits: Domain to object mapping happens where

问题 I have a Rails 3 application, say, with hotels, where hotels belong to parent areas. When a user hits the app (served by mongrel >> nginx), I want the domain name used in the request to decide what area of hotels to serve up (domain name >> area). To achieve this I can see two options: 1) Rewrite the URL with nginx, inserting the area id after the domain name (e.g. birminghamhotels.co.uk => proxy_pass http://myupstream/areas/3$request_uri). Benefits: Domain to object mapping happens where

问题 Im not quite sure how to read ternary relationships within a ER-Diagram. Lets say this is the ternary relationship that is given. What can I interpret out of that? It says that you have to put your hand on 2 entity sets and then read it like that. Hand on Account and User: A pair of Account and User can be associated with M projects. Hand on Account and Project: A pair of Account and Project can be associated with M users. Hand on Project and User: A pair of Project and User can be associated

问题 I've written a new model for my CodeIgniter framework. I'm trying to load the database from within the constructor function, but I'm getting the following error: Severity: Notice Message: Undefined property: userdb::$load Filename: models/userdb.php Line Number: 7 Fatal error: Call to a member function database() on a non-object in /var/www/abc/system/application/models/userdb.php on line 7 Here is my model: <?php class userdb extends Model { function __construct() { $this->load->database();

问题 I've written a new model for my CodeIgniter framework. I'm trying to load the database from within the constructor function, but I'm getting the following error: Severity: Notice Message: Undefined property: userdb::$load Filename: models/userdb.php Line Number: 7 Fatal error: Call to a member function database() on a non-object in /var/www/abc/system/application/models/userdb.php on line 7 Here is my model: <?php class userdb extends Model { function __construct() { $this->load->database();

问题 I've written a new model for my CodeIgniter framework. I'm trying to load the database from within the constructor function, but I'm getting the following error: Severity: Notice Message: Undefined property: userdb::$load Filename: models/userdb.php Line Number: 7 Fatal error: Call to a member function database() on a non-object in /var/www/abc/system/application/models/userdb.php on line 7 Here is my model: <?php class userdb extends Model { function __construct() { $this->load->database();

问题 I am migrating a rails 5.1 app to rails 5.2.1. In my models I am using callbacks to create an activity log after a model was created or updated. Unfortunately todo.name and todo.name_was is always the same - the current value. This applies to every attribute and every model. Also changed? returns false. Am I missing something? I appreciate your help a lot! 回答1: You won't get attribute_was in after_create/update callback as the records has been changed in DB at this point. You can make use of