Problem changing from PHP 5.6 to PHP 7.2
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60% Downpayment on house? Clearing Flag Bits By Writing 1 I`m using the Newton-Raphson method for obtaining MLE for parameters for maximizing my objective function. At each iteration, I want to check that is the Hessian matrix negative definite or not and I see the Hessian matrix is not negative definite at some iterations. So, I want to use the Fisher scoring algorithm ( of derivation) In this situation, the Fisher information matrix is indefinite!! Is it possible? What are the reasons for this? Are the second-order derivatives wrong? Or are values of expectations incorrect? I've setup a HTTPS and FTP site in IIS but how can I add users to use the FTP site?  Does they necessarily need an account with password in the computer to be able to use it? A locally constant sheaf on a locally connected space is a covering space; Proof? What are the differences between Factor Analysis and Principal Component Analysis? It seems that a number of the statistical packages that I use wrap these two concepts together. However, I'm wondering if there are different assumptions or data 'formalities' that must be true to use one over the other. A real example would be incredibly useful. Relative Pronouns are ALWAYS added right after antecedent? Is is a rule that relative clauses should be added right after the antecedent(the noun relative pronouns refer to)? What if it is confusing?   For example:  "I went for a spin with a handsome boy last night."  "The handsome boy went out with my friend."  "I went for a spin with a handsome boy who went out with my friend last night ."  "I went for a spin with a handsome boy last night who went out with my friend." Foreign key constraint on array member? Suppose I have a table containing job roles:  CREATE TABLE roles (   "role" character varying(80) NOT NULL,   CONSTRAINT "role" PRIMARY KEY (role) );   Suppose I further have a table, users, and each row (a specific user) can have an arbitrary number of job roles:  CREATE TABLE users (   username character varying(12) NOT NULL,   roles character varying(80)[] NOT NULL,   CONSTRAINT username PRIMARY KEY (username) );   I should probably make sure that each member of users.roles[] exists in roles.role.  It seems to me that what I want is a foreign key constraint on each member of users.roles[] such that if references roles.role.  This doesn't seem possible with postgres.  Am I looking at this the wrong way?  What is the suggested "right" way to handle this? Why is a nonstop flight sometimes more expensive than multiple connections? How to merge partitions? I have two partitions, one of them has a file system and the other is unallocated.  How to merge two partitions? How can I prove that the Cartesian product of two countable sets is also countable? How do tag merge requests work? I had raised a  to merge pre-build-event, and pre-buildevent; and postbuild-event and post-build-event. That was about 11 months ago, and I still see these two tags even now.  How are tag merge requests handled? Is there a better way for tag merge requests other than posting on Meta? Why would I want to use Interfaces? I understand that they force you to implement methods and such but what I cant understand is why you would want to use them. Can anybody give me a good example or explanation on why I would want to implement this. Let $R= \mathbb{Q}[x^2 ,x^3 ]$, the set of all polynomials over $\mathbb{Q}$ with no $x$ term. Show that a gcd of $x^5$ and $x^6$ does not exist in $R$.   I am reasoning for the absurd and I am assuming that $gcd (x ^ 5, x ^ 6) = ax ^ 2 + bx ^ 3\in\mathbb{Q}[x^2 ,x^3 ] $, then, for the Bezout identity there exists $p (x) = cx ^ 2 + dx^3$ and  $q(x)= ex ^ 2 + fx ^ 3$ in $\mathbb{Q}[x^2 ,x^3 ]$ such that $x ^ 5p (x) + x ^ 6q (x) = ax ^ 2 + bx ^ 3$, which is absurd since $$9 = deg (x ^ 5p (x) + x ^ 6q (x)) \neq  deg (ax ^ 2 + bx ^ 3) = 3.$$  Is it okay what I did? Thank you very much. Why is my toilet bubbling? Last night while my washing machine and sink in the master bath was running, my master toilet started having air bubbles come up.  Then this morning while I was showering I heard bubbles again, and the shower was draining very slowly.  After the bubbles occurred my toilet in the master bath and powder room completely drained of water in the bowl and tank.  What is happening? "The volume boot has only 0 bytes disk space remaining" After a recent update, I'm getting an alert saying:  The volume boot has only 0 bytes disk space remaining   But my computer has plenty of HD space free. Does anyone know how I resolve this. (If it's relevant, I'm using the whole disk encryption feature of the alternate install image for Ubuntu 12.04). In Random forest algorithm, Breiman (author) constructs similarity matrix as follows:   Send all learning examples down each tree in the forest If two examples land in the same leaf increment corresponding element in similarity matrix by 1 Normalize the matrix with number of trees   He says:     The proximities between cases n and k form a matrix {prox(n,k)}. From their definition, it is easy to show that this matrix is symmetric, positive definite and bounded above by 1, with the diagonal elements equal to 1. It follows that the values 1-prox(n,k) are squared distances in a Euclidean space of dimension not greater than the number of cases.    In his implementation, he uses sqrt(1-prox), where prox is a similarity matrix, to convert it to distance matrix. I guess it has something to do with the "sqaured distances in a Euclidean space"-quoted above.  Can somebody shine a little light on why it follows that 1-prox are squared distances in a Euclidean space and why he uses squared root to get distance matrix? Prove that a continuous function on a closed interval attains a maximum Is every discrete absolute value non-archimedean? I've been reading Milne's notes on absolute values and local fields (Chapter 7 of the book on algebraic number theory), and a possibly minor point is confusing me.   On page 126, Milne writes, "$K$ is a field complete with respect to a discrete absolute value $|\cdot|$..." and then he talks about things that only make sense for non-archimedean absolute values, like the ring of integers and its maximal ideal.   Is every discrete absolute value on a field $K$ also non-archimedean? This would explain a lot, but I also suspect that it is not true, because I can't find any statement of this fact anywhere.  EDIT: An absolute value is discrete if the value group $|K^\times|$ is a discrete subgroup of the multiplicative group $\mathbb{R}_{&gt;0}$. An absolute value is non-archimedean if it satisfies the stronger triangle inequality $$ |x+y| \le \max (|x|,|y|) $$ or equivalently if the set $\{|1|,|1+1|,|1+1+1|,\ldots\}$ is a bounded subset of $\mathbb{R}$. Rich Snippets not working (and working at the same time?)