saddle | SADDLE : Scala Data Library | Data Manipulation library

I have a datatables table of many rows of data; and a pair of custom buttons as per the Datatables documentation:

I am learning about linear optimization in R using the lpSolve package. I am wondering if the lp() function in R can sometimes find a solution that is a saddle point and not the true min/max. I have looked at the documentation of the package and I haven't found anything about saddle points or how the optimization function works. Do you know if this is possible?

I’m trying to find the saddle point of a 2d Matrix and refer back to the Matrix by using a pointer, but my code isn’t executing as intended.

here is my code

REMARK :

• I use term mocking as a general term meaning all kind of test substitutes inluding spies, fakes, mock, stubs and all the rest.
• In writing my question I have only speak of "use cases" in clean architecture, but my question also concerns "Domain Services" in DDD.

Let's go :

I am currently trying to implement DDD and Clean Architecture principles in a new project. However, it's been 1 week that I have been stuck on ---> How to write my unit test for my use case

In Clean Architecture, when we create a use case (or a Domain service in DDD), it will depend in most cases on a certain number of entities + the rest (repository, api ...)

To write my unit test of my use case, I start with:

- Mock "the rest" of dependencies that interact with the outside (repositories, API ...)

- But next, what should I do with the entities dependencies in my unit test?

Here are the solutions I thought of :

• Solution 1: I'm injecting fake entities

- However, through my reading about unit test best practices, I understand that we should avoid creating mocks as much as possible because they are "Code Smells" and a good design should make it possible to do without them.

- Indeed, mocking my entities implies that I weaken my test. The test will be tightly coupled to my mocked entities.

- In addition, recreating the structure of my entities seems meaningless to me ...

* If my use case uses multiple entity methods: then I should have to recreate the return value of each of those methods.

* If the structure of my entities is complex I end up with complicated fakes to write, therefore my test loses a lot of reliability and there is a more chance that my fake is wrong, rather than my original entity)

* Even worse, if I use a factory, then I will have to make a fake of the factory -> and that fake will have to build a fake entity ...

• Solution 2: I don't mock entities.

- On the other hand, if I do not mock my entities, then I take the way in my opinion into integration tests: testing the interactions between the different entities ...

- Also as specified by some mocking supporters: If I don't mock my dependencies, then even if my tested unit is valid, the test will fail if my dependency causes a bug. This will cause a false alarm signal on my test ...

• Solution 3: Refactoring the production code

- By reading several articles some offer solutions to limit the coupling (Isolate the side effects from the rest of the logic, Isolate the logic from I/O, Use pure functions, Dependency injections, ...) But even by applying all this, a use case will irremediably need these entities to work ... Therefore it is not a solution.

But then how to do? Am I missing something?
How to do a GOOD unit test on a use case (or a service domain in DDD)? : how to manage the entities in a unit test in which the tested unit has entity depenencies ?

To illustrate my question, and to better understand your answers, here is a fictitious example of the problem:

Imagine that I have the following entity:

Let's say I have two DataFrames (Samples and Controls) as follows:

I am new to C#. I am trying to connect COSMOS DB in C# using MongoAPI web driver. I am following their documentation and trying to get data from my collection.

In the documentation, they gave sample Templates/APIForMongoDBQuickstart-WebAPI

Initially, by their sample data collection, I uploaded this document into my collection and I am able to run the get Products from getting Product API.

I have a project where I need to do a update multiple rows at once. I have found the example on how to do this is the docs: documentation

I have done used a columnset because it is being recommended to do to in the documentations. I have set the ?feature_id so it is only used in the WHERE clause.

The error my code is generating is the following: error: column "created_on" is of type timestamp with time zone but expression is of type text. I have noticed in the query that is being generated and that seems to be in line with the example.

This code has an insert statement for the features that are new and that seems to work fine. The error is only being thrown on the update query.

I have a project where I need to update a features of items that are linked to a plot. The API call gets a list of features. I first do a search in the database to find all exciting feature_id's for that specific plot.

Then I update all the plots that have that are contained within the array of exciting id's and I insert all those who are not.

The inserting part works fine. But I have a problem with the updating. If I want to update I always get the following error error: missing FROM-clause entry for table "y"

Background

I have a table and one of the column contains data that looks like this: