Factorio: Cannot Finish Steam Engine Campaign Mission
Why does this steam engine fail to run?
I am playing with LINQ to learn about it, but I can't figure out how to use Distinct when I do not have a simple list (a simple list of integers is pretty easy to do, this is not the question). What I if want to use  on a list of an Object on one or more properties of the object?  Example: If an object is Person, with Property Id. How can I get all Person and use Distinct on them with the property Id of the object?  Person1: Id=1, Name="Test1" Person2: Id=1, Name="Test1" Person3: Id=2, Name="Test2"   How can I get just Person1 and Person3? Is that possible?  If it's not possible with LINQ, what would be the best way to have a list of Person depending on some of its properties in .NET 3.5? Is there a difference between them? If so, how and when are they used?  For example:     I fixed a little/small typo. In a field that is the direct product of two fields, why isn't it a field? Suppose that we have the direct product of two fields, defined as: $\mathbb{F}^2 = \mathbb{F} \ \times\ \mathbb{F}$. Then, this is obviously not a field because we can take $(1,0)$, and this doesn't have a multiplicative inverse. However, I saw a mention to this today in a book, and the reasoning was:     "$\mathbb{F} \ \times\ \mathbb{F}$ has the zero-divisor $(1,0) \neq  (0,0)$, hence it is not a field".   (Lectures on Rings and Modules by Joachim Lambek, pg. 17).  I am not sure what they mean by zero-divisor here nor what $(1,0) \neq  (0,0)$ has anything to do with the direct product of fields not being a field. I always assumed there wasn't a multiplicative inverse, and that was it. Am I missing something deeper? Insert image from Google Drive into Google Sheets How do I insert/link to images existing in a folder in Google Drive into a Google Sheets spreadsheet?  There is the image() function, I imagine using it something like this:  image("googledrive://somefodleringoogledrivewithmypics/pic_1.png")   How?  Update: Some people noted that by uploading pictures to Picasa, we can then get the URL of each picture and use that. It works. The downside of this is that we have to copy each and every URL of all images. I put that in a separate sheet, then use VLOOKUP to get each image URL per index. It works but the URL copying part is a hell of a job if you have lots of images of course. A better solution is needed. Why is my total reputation less than my monthly reputation? When I went to the  to see my ranking in the reputation league, I saw this. Is this an error? My total reputation is less than my monthly reputation. "Dummy Output" No sound in Ubuntu 16.04 None of the HDMI output are working, all saying "dummy output", it was working yesterday, but when I use the headphones it became soundless, with or without the headphones.  Thank you already! I am a little bit confused by early stopping and in particular by how it can be inserted inside a CV framework. As far as I understand, I can fix the optimal number of epochs (for NN, or number of trees for XGB) by early stopping, that is:   pick a validation set, train with increasing number of epochs until a predefined metric evaluated on the validation set starts worsening that is the optimal number of epochs to prevent overfitting   and that's fine. But then I would like to insert this early stopping framework inside a CV framework: Suppose I have a model with 10 hyperparameters I want to fix via CV. And suppose that there is an eleventh hyperparameter, the number of epochs. My feeling is that one can do like this:   create the K resampled folds, for each of which you have a training and validation set choose a suitable grid for your 10 hyperparameters for each point on the grid train your model in each fold with early stopping, that is use the validation set of the fold to keep track of the preferred metric and stop when it gets worse take the mean of the K validation metric choose the point of the grid (i.e. the set of hyperparameters) that gives the best metric   Questions:   What number of epochs should I choose as optimal? in each of the K folds I have, in general, a different number of stopping epochs.  seems to suggest they take the mean of the K stopping epochs. Is this right? Is it actually a "fair" practice to use the validation metric coming from the early stopping as a proxy of the out-of-sample metric? As  in section 3.4.5, maybe the best thing to do would be:     ...if you want to do early stopping, then in each fold you should take your training set and split it again, holding out a small early-stopping-set to guide the early stopping, and then evaluate the model on the validation set of that fold.   But this seems to me a really intricate process...   Unfortunately, I wasn't able to find references where this issue is presented in a clear and transparent form. Why $e^x$ is always greater than $x^e$? I find it very strange that $$ e^x \geq x^e \, \quad \forall x \in \mathbb{R}^+.$$   I have scratched my head for a long time, but could not find any logical reason. Can anybody explain what is the reason behind the above inequality? I know this is math community, but I'd appreciate a more intuitive explanation than a technical one. I had Ubuntu 12.04 Beta installed on my computer. When 12.04 was finally released, I made a bootable USB Flash Drive using Startup Disk Creator.  Then I decided to check if this drive works properly and to reinstall the system on my desktop. I must add, my desktop behaves a bit strange when it comes to bootable USB's, it recognizes them as HDD.  In BIOS I changed priority of boot so USB Flash Drive (recognized as HDD) was first. Successfully booted, I installed Ubuntu. Everything worked fine, but...  Now I cannot boot from my real HDD. Every time I want to boot, I put the USB Flash Drive into my computer, boot, safely remove it and everything works.  What do I need to do to repair boot? I was very inspired by Michio Kaku's  on the possibilities of quantum computing and also listening to Talia Gershon's  on it.   As I come from a business &amp; analytics background, what materials can I begin exploring to prepare to learn more about the field of quantum computing? Eg. what would I need to study to understand Peter Shor's algorithm,  on physics, etc. How does the new Tie-Breaker work? In Clash of Clans there was an update on 9/16 adding a Tie-breaker into the wars, can anybody explain in detail how this mechanism works? What is the most portable method of launching a terminal emulator? How do I set a background image while I am editing? I am going to Santa Monica for 4 weeks to polish my English in July and would like to volunteer at the Planetary Society located in Pasadena.  I am a Swiss citizen and have a biometric passport. However, I don't have any special visa, as there is no visa needed for the school I am attending and using the Visa Waiver Program, I am allowed to stay up to 90 days in the US.  Am I allowed to do volunteer work during my stay? Early 80s anthology book about human kind being feared by other races in space I always thought the book was Manifest Destiny but its not. The story that sticks in my head was a human in a cage over a pit? Aliens walk in and discuss how dangerous humans were. He eventually escapes. Man I miss this book. wish I wouldve written down every book I ever read. Ugh How do I Sort a Multidimensional Array in PHP After upgrading to 13.10, I am now getting a prompt for my gmail password every time I log in. There is no indication as to which service or application needs this information. If I enter the correct password I'm told it is incorrect. My gmail account does not use two factor authentication. The problem has only started after an upgrade from 13.04 to 13.10.  How can I prevent this prompt appearing, and/or what is doing the prompting? How can I get a complete list of fields for a standard object? Is it possible to search for punctuation/special characters? I tried to find a related question here, but was unsuccessful.  Someone on SO asked ... I tried searching SO and was presented with the search options page. Even Google fails at this search.  So my question is, is there some way to search for an exact word (in quotes) that won't cause it to fail? Selecting and manipulating CSS pseudo-elements such as ::before and ::after using javascript (or jQuery)