model

问题 I would like to run the following model three times with a different seed. For example, the following model is run with seed 314159 set.seed(314159) x <- c(11, 5, 2, -5, 7, 2, -11, 9, -5, -5, -4, 17, 2, -10, -11, -10, -4, 2, 1, 13) a <- 0.1 b <- 0.1 c <- 0 d <- 100^2 M <- 1e3 sample <- array(NA, dim=c(M,2)) mu <- mean(x) sig2 <- var(x) for( m in 1:M ){ mu <- rnorm(1, (length(x) + 1/d)^(-1) * (sum(x) + c/d), sqrt( sig2/(length(x) + 1/d) )) sig2 <- rigamma(1, .5*length(x)+a+.5, .5*sum( (x-mu)^2

问题 I'm using wagtail CMS for Django, I want to add a dynamically populated value for a dropdown and save it on the Page model, this is my code: class MyPage(Page): domain = CharField(max_length=10, choices=MY_CHOICES) subdomain = CharField(max_length=10, choices=[('', '------')] I've got some frontend logic to populate dynamically the options for subdomain, but after I hit save I got: The page could not be created due to validation errors And in the subdomain field: Select a valid choice. [my

问题 First of all, I have been a php programmer for a long time and I am a mvc programmer newly. I did a few minor web sites that each have one or two controller at most. But I've started a website that will be very major web site. There will be a lot of data to pass to views. Now, normally I try to use model approach every time instead of ViewBag or ViewData approach. If the view demands more data, then I change the model class and then recompile the project. Especially, if the topic is an index

问题 I'm using Open CV and I'm able to extract multidimensional data from and image with my codes but what would be an easy way to display it? I have a 3D array: line start [x] [y] [z] line end [x] [y] [z] Anything in between the lines will be filled with a solid flat surface. Is there some kind of function I can use to easily display a 3d image given these points or whatever other points I'm missing? Such as this pseudo code: display_3d(x,y,z,angle) Any help is highly appreciated. Also I'm using

问题 So I'm parsing data from twitter api in rails using the twitter library, and sometimes the response from api might be like this: { error: "Invalid parameter" } And the model will raise an exception, right now I'm silently catch it and put the error.message into the log, how do I pass this exception to the controller so I can display it on the view? Thanks. UPDATE: The error is likely to happen because I'm allowing my customer to build queries, and they might put advanced queries like "https:/

问题 So I'm parsing data from twitter api in rails using the twitter library, and sometimes the response from api might be like this: { error: "Invalid parameter" } And the model will raise an exception, right now I'm silently catch it and put the error.message into the log, how do I pass this exception to the controller so I can display it on the view? Thanks. UPDATE: The error is likely to happen because I'm allowing my customer to build queries, and they might put advanced queries like "https:/

问题 i've been trying to query a moodle database and need to use DB::raw(). but it keeps trying to use the default mysql connection. here's the query i'd like to run. SELECT mdl_course.id, mdl_course.category, mdl_course.fullname, mdl_course_categories.name, mdl_enrol.cost, FROM_UNIXTIME(mdl_course.startdate, '%m/%d/%y') AS startdate FROM mdl_course LEFT JOIN mdl_course_categories ON mdl_course_categories.id = mdl_course.category LEFT JOIN mdl_enrol ON mdl_enrol.courseid = mdl_course.id AND mdl

问题 i've been trying to query a moodle database and need to use DB::raw(). but it keeps trying to use the default mysql connection. here's the query i'd like to run. SELECT mdl_course.id, mdl_course.category, mdl_course.fullname, mdl_course_categories.name, mdl_enrol.cost, FROM_UNIXTIME(mdl_course.startdate, '%m/%d/%y') AS startdate FROM mdl_course LEFT JOIN mdl_course_categories ON mdl_course_categories.id = mdl_course.category LEFT JOIN mdl_enrol ON mdl_enrol.courseid = mdl_course.id AND mdl

问题 Here a simple django model: class SomeModel(models.Model): title = models.CharField(max_length=100) video = models.FileField(upload_to='video') I would like to save any instance so that the video 's file name would be a valid file name of the title . For example, in the admin interface, I load a new instance with title "Lorem ipsum" and a video called "video.avi". The copy of the file on the server should be "Lorem Ipsum.avi" (or "Lorem_Ipsum.avi"). Thank you :) 回答1: If it just happens during

问题 We have an application with three layers: UI, Business, and Data. The data layer houses Entity Framework v4 and auto-generates our entity objects. I have created a buddy class for the entity VendorInfo : namespace Company.DataAccess { [MetadataType(typeof(VendorInfoMetadata))] public partial class VendorInfo { } public class VendorInfoMetadata { [Required] public string Title; [Required] public string Link; [Required] public string LinkText; [Required] public string Description; } } I want