I have the following code:  public class Test2 {     public static void main(String[] args) {          long ta, after, before;         Runtime rt;         rt=Runtime.getRuntime();         rt.gc();         NodoPrueba q=new NodoPrueba(1);          before=rt.freeMemory();         q=null;         rt.gc();         after=rt.freeMemory();         ta=after-before;         System.out.println("Before: "+before+"\nAfter: "+after);         System.out.println("\nDifference: "+ta);     }  }   Well, the class NodoPrueba only has an int attribute. But i have the following output:  Before: 127991976  After: 128673800  Difference: 681824  If the theory says that NodoPrueba class only takes 16 bytes on memory: 8 bytes from the object, 4 bytes for int and 4 bytes for padding (object's size is always a multiple of 8), where does the difference come from?
I have an application that reads a CSV file with piles of data rows.  I give the user a summary of the number of rows based on types of data, but I want to make sure that I don't read in too many rows of data and cause OutOfMemoryErrors.  Each row translates into an object.  Is there an easy way to find out the size of that object programmatically?  Is there a reference that defines how large primitive types and object references are for a VM?  Right now, I have code that says read up to 32,000 rows, but I'd also like to have code that says read as many rows as possible until I've used 32MB of memory.  Maybe that is a different question, but I'd still like to know.
I have Ubuntu 13.1 installed with the default window manager and DE.   I am trying to enable single click so I can open files and folders with only one click. I tried googling and all results said to open files, then go to preferences from top bar but my top bar has no options.  picture of desktop: What follows if we fail to reject the null hypothesis? is a dove a "she"? how to use "he" and "she" for animals? In the song &quot;Blowing in the Wind&quot; by Bob Dylan, there's a verse that reads:  Yes, and how many seas must a white dove sail Before she sleeps in the sand?  My question is, why he used &quot;she&quot; for a dove? What about other animals and other non-humans? Is there a general rule? Proof of $(\mathbb{Z}/m\mathbb{Z}) \otimes_\mathbb{Z} (\mathbb{Z} / n \mathbb{Z}) \cong \mathbb{Z}/ \gcd(m,n)\mathbb{Z}$ I've just started to learn about the tensor product and I want to show: $$(\mathbb{Z}/m\mathbb{Z}) \otimes_\mathbb{Z} (\mathbb{Z} / n \mathbb{Z}) \cong \mathbb{Z}/ \gcd(m,n)\mathbb{Z}.$$  Can you tell me if my proof is right:  $\mathbb{Z}/m\mathbb{Z}$ and $\mathbb{Z} / n \mathbb{Z}$ are both finite free $\mathbb{Z}$-modules with the basis consisting of one single element $\{ 1 \}$. So $(\mathbb{Z}/m\mathbb{Z}) \otimes_\mathbb{Z} (\mathbb{Z} / n \mathbb{Z})$ has the basis $\{ 1 \otimes 1 \}$.  Therefore, any element in $(\mathbb{Z}/m\mathbb{Z}) \otimes_\mathbb{Z} (\mathbb{Z} / n \mathbb{Z})$  is of the form $(ab) 1 \otimes 1$ and any element in $\mathbb{Z}/ \gcd(m,n)\mathbb{Z}$ is of the form $k 1 = k$ where $k \in \{ 0, \dots , \gcd(n,m) \}$.  I would like to construct an isomorphism that maps $ab$ to some $k$. Let this map be $ab (1 \otimes 1) \mapsto ab \bmod \gcd(n,m)$.  This is a homomorphism between modules: it maps $0$ to $0$ because it maps the empty sum to the empty sum. It also fulfills $f(a + b) = f(a) + f(b)$ because there is only one element, $a = 1$.   It is surjective. So all I need to show is that it is injective. But that is clear too because if $ab \equiv 0 \bmod \gcd(m,n)$  then both $a \equiv 0 \bmod n$ and $b \equiv 0 \bmod m$ so the kernel is trivial.  Many thanks for your help!! Does "minor revision" mean "accepted with minor revision"? I just received a decision letter from a journal editor (after three rounds of major revision). The letter shows that the reviewers "have asked for some other minor revisions". After getting the minor revision letter, I immediately completed the revision in accordance with the feedback from the reviewers (the suggested changes just involve adding a few sentences) and immediately resubmitted the revision to ScholarOne. A week has passed since I submitted the revision, but the status in ScholarOne remains unchanged. Is this normal? Can I assume that this basically means "acceptance with minor revision"? Thanks for your insight and sharing. Listing multiple compound words How do I list multiple things that are compound words?  In my own language I'm used to writing these lists like this:  "I kicked foot-, basket-, and volleyball"  The sentence is supposed to mean that I kicked all types of balls (football, basketball and volleyball). However, it does not seem correct to me. Should I write them as whole words, with or without hyphen, or how? How to find range $a_{75}$ of the term of the series $a_n=a_{n-1}+ {1 \over {a_{n-1}}} $ If $a_1=1$ and for n&gt;1$$a_n=a_{n-1}+ {1 \over {a_{n-1}}} $$ $a_{75}$ lies between (a) (12,15) (b) (11,12) (c) (15,18)  Now , in this question, I rewrote, $a_n-a_{n-1} = {1 \over {a_{n-1}}}$, to make a telescopic type and summed the terms to get $$a_n-a_{1}= {1 \over {a_{n-1}}}+ {1 \over {a_{n-2}}}...{1 \over {a_{1}}}$$ And as ${1 \over {a_{r}}} &lt;1$ for all r , I got $a_{75} &lt;76$ , but it's of no help as , the upper bound is much higher. I got no further ideas , on how to solve it, please help. Avoid synchronized(this) in Java? state that "at best" is an idiom. But, what is the grammatical function of "at best" (for example, in the below sentences?)        Their response to the proposal was, at best, cool.   The government's response seems to have been at best confused and at   worst dishonest.   If he drops the course now, at best he’ll get an incomplete, and he could fail.      Thanks Explaining Horizontal Shifting and Scaling If an edit was suggested to an answer to my question and I go to this edit, I see the checkmark Android/Java - Date Difference in days How to generate a random number between 1 and 10 with a six-sided die? This questions has been asked before too and I did go through most of the suggestions. Things I have tried so far: setting up correct  path variable environment, installing anaconda 32 bits, python 2.7, or even switching to python 2.7 in cmd while initially using Anaconda 3 , adding Desktop 10.4.pth file with  following path.  C:\Program Files (x86)\ArcGIS\Desktop10.4\bin C:\Program Files (x86)\ArcGIS\Desktop10.4\ArcPy C:\Program Files (x86)\ArcGIS\Desktop10.4\ArcToolBox\Scripts   I also added those paths in environment variable   These suggestions help me to reduce the error. But Now I am getting a different error. Looks like python can find arcpy but missing another package.  Getting this error while trying to import arcpy in python 3.6.   File "C:\Program Files (x86)\ArcGIS\Desktop10.4\ArcPy\arcpy\__init__.py", line 22, in &lt;module&gt;     from arcpy.geoprocessing import gp    File "C:\Program Files (x86)\ArcGIS\Desktop10.4\ArcPy\arcpy\geoprocessing\__init__.py", line 14, in &lt;module&gt;     from _base import *  ModuleNotFoundError: No module named '_base'   Any suggestions? Find a function $f: \mathbb{R} \to \mathbb{R}$ that is continuous at precisely one point? Is the function $f(x) = \lim_{k \to +\infty} \tan{kx}$ a right example?  But I do not know whether this is a function at first. Is this a function?  Could you give a correct real-valued function that is continuous at precisely one point?  Thanks. Making holes in an object using an image as a reference I have an object already created in blender, a tree, or a human, or a pipe.. and I need this to be drilled with multiple holes.   The holes are painted in an image, that is, it is an image that has a repeating an images pattern (they can be circles, squares, or any form).  Here are some examples for drilling-pattern: I've never really thought about how the shell actually executes piped commands. I've always been told that the "stdout of one program gets piped into the stdin of another," as a way of thinking about pipes. So naturally, I thought that in the case of say, A | B, A would run first, then B gets the stdout of A, and uses the stdout of A as its input.    But I've noticed that when people search for a particular process in ps, they'd include grep -v "grep" at the end of the command to make sure that grep doesn't appear in the final output. This means that in the command ps aux | grep "bash" | grep -v "grep" it is implied that ps knew that grep was running and therefore is in the output of ps. But if ps finishes running before its output gets piped to grep, how did it know that grep was running?   flamingtoast@FTOAST-UBUNTU: ~$ ps | grep ".*" PID TTY          TIME CMD 3773 pts/0    00:00:00 bash 3784 pts/0    00:00:00 ps 3785 pts/0    00:00:00 grep Necessary and sufficient condition for the matrix $A = I - 2 x x^t$ to be orthogonal Let $x$ be a non zeo (column) vector in $\mathbb{R}^n$. What is the necessary and sufficient condition for the matrix $A = I-2xx^t$ to be orthogonal? What is the definition of how to count degrees of freedom? resulted, rather as by-product, the discussion on how to count degrees of freedom (DOF). I extend that question here:   Are necessary1 derivatives such as velocities counted as individual DOFs or together with the respective coordinate2? Should complex valued DOFs be counted twice as in "two real-valued DOFs" or once as in "one complex-valued DOF"? (I mean, when one does not want to specify this explicitly)   Please answer with some reference, unless it turns out this is actually a matter of taste rather than a strictly defined thing.    1) I mean those a value of which is required as an initial condition 2) I count fields in QFT as coordinates as well, while space-time-coordinates are parameters to me, if that matters. I know a field actually has $\infty$ (or rather, $2^\aleph$) DOFs itself, but let's say e.g. "one $\mathbb R^3$ continous DOF" in that case Show that AB is singular if A is singular Actually I need to show that $\det(AB) = \det(A)\det(B)$ if $A$ is a singular matrix.  The determinant of $A$ is $0$ if $A$ is singular, so $\det(AB)$ has to be $0$ as well, but I have problems showing that $AB$ is singular if $A$ is singular. How can I show that?