As I'm planning to buy an SSD and replace my old mechanical hard drive, I've heard rumors that having swap partition can decrease the life of SSD. So is this true? Or can I still have a swap partition on my SSD?
I have a Samsung 960 Pro SSD with Ubuntu 18.04  is it safe to put the swap file on there or would it hurt it in the long run,  I heard some people saying that new SSDs don't suffer from that issue anymore, is this true?
How do I get my Epson Scanner working on Ubuntu 13.10 I have the Epson SX218 with a built-in scanner. The printer works fine but if I want to scan something simple scan says no scanner found.  Any ideas what I can do?  By the way, how can I check the ink level of the printer?? PHP syntax for dereferencing function result Give each NodeJs Process a name in Windows TaskList Why does a Ubuntu guest in VirtualBox run very, very slowly? I'm using currently Ubuntu 12.04 LTS as a host machine, and I've virtualized three machines:   a Xubuntu 12.04 guest a Windows 7 guest a Ubuntu 12.10 guest   All the guests have the same VirtualBox default settings, but Ubuntu 12.10 is slower!  The installation took 1h 40 min! (Normally, it takes 40 minutes.) Now it is impossible to use it, and all operations are very, very slow.  I'm using VirtualBox version 4.2.4.  Any ideas?  Why is it slow? And how can I make it faster? Lines appear on the texture in render I am trying to learn Blender. While trying to render a subdivided plane with an image texture applied to it, the subdivision edges are not removed in the rendered result.  Kindly, advise, why these edges appear in the render. How to programmatically create a WPF window in a WinForm application How to call gdal_translate from Python code? Is it possible to use some gdal API to call gdal_translate from Python code? I do not mean simply executing the gdal_translate.exe from the file system, but rather call it somehow in code so I do not need to know the exact directory the gdal_translate executable is in? If $p$ is prime, then $(x+y)^p=x^p+y^p$ holds in any field of characteristic $p$. However all the proofs I have seen use induction and some relatively nasty algebra despite how fundamental this fact seems.  What is the nicest, "highest level proof" you know? Is it supposed to be a HTML or an HTML Solenoid Driving Circuit I'm trying to drive a 12v (14W) solenoid and have problems figuring out the components for the driving circuit.  The solenoid draws about 1.166A and the MCU is being operated at 3.3V.  I've seen many driving circuits and they all look something like this:         &ndash; Schematic created using   My questions:   What datasheet parameters should I look for when designing this circuit? Is the IRF530PBF-ND a suitable MOSFET for driving this solenoid?    Also, how do I calculate R1's value?  I don't want to blindingly copy a circuit that may or may not work, I want to understand it.  Thank you so much in advance! Trying to identify a short sci-fi story about a human that is "resurrected" by malignant aliens Here is a question that's been bothering me since I was a sophomore in university, and should have probably asked before graduating:  In analytic (Lagrangian) mechanics, the derivation of the Euler-Lagrange equations from the principle of least action assumes that the start and end coordinates at the initial and final times are known. As a consequence, any variation on the physical path must vanish at its boundaries. This conveniently cancels out the contributions of the boundary terms after integration by parts, and setting the requirement for minimal action, we obtain the E.L. equations.  This is all nice and dandy, but our intention is finding the location of a particle at a time in the future, which we do not know a priori; after we derive any equations of motion for a system, we solve them by applying initial values instead of boundary conditions.   How are these two approaches consistent? Mysql resolving 127.0.0.1 to hostname Determine all $f : \mathbb R \rightarrow \mathbb R$ such that $f(f(x) + y) = f(x^2 - y) + 4yf(x)$. Determine all $f : \mathbb R \rightarrow \mathbb R$ such that $$f\big(f(x) + y\big) = f(x^2 - y) + 4yf(x)$$ for all $x,y\in\mathbb{R}$.   $f(x) = 0$ is obvious , but how can we find all other functions?  Thanks in advance! How to print file content only if the first line matches a certain pattern? I have recently been reading a lot on this site (@Aniko, @Dikran Marsupial, @Erik) and elsewhere about the problem of overfitting occuring with cross validation - (Smialowski et al 2010 Bioinformatics, Hastie, Elements of statistical learning).  The suggestion is that any supervised feature selection (using correlation with class labels) performed outside of the model performance estimation using cross validation (or other model estimating method such as bootstrapping) may result in overfitting.   This seems unintuitive to me - surely if you select a feature set and then evaluate your model using only the selected features using cross validation, then you are getting an unbiased estimate of generalized model performance on those features (this assumes the sample under study are representive of the populatation)?  With this procedure one cannot of course claim an optimal feature set but can one report the performance of the selected feature set on unseen data as valid?  I accept that selecting features based on the entire data set may resuts in some data leakage between test and train sets. But if the feature set is static after initial selection, and no other tuning is being done, surely it is valid to report the cross-validated performance metrics?   In my case I have 56 features and 259 cases and so #cases > #features. The features are derived from sensor data.  Apologies if my question seems derivative but this seems an important point to clarify.  Edit: On implementing feature selection within cross validation on the data set detailed above (thanks to the answers below), I can confirm that selecting features prior to cross-validation in this data set introduced a significant bias. This bias/overfitting was greatest when doing so for a 3-class formulation, compared to as 2-class formulation.  I think the fact that I used stepwise regression for feature selection increased this overfitting; for comparison purposes, on a different but related data set I compared a sequential forward feature selection routine performed prior to cross-validation against results I had previously obtained with feature selection within CV. The results between both methods did not differ dramatically. This may mean that stepwise regression is more prone to overfitting than sequential FS or may be a quirk of this data set. apt-get build-dep is unable to find a source package When does the amount of skew or prevalence of outliers make the median preferable to the mean? I know that "deviations in the data are devil", and when the distribution is highly skewed, it is better to consider median as average rather than mean, but how to decide these hard-limits.  For example:   CASE 1:   Assume X = 10,20,30,40,50,60,70 In this case, I think that it is better to use mean and that it will give very accurate results.  CASE 2:   Assume X = 10,20,30,40,50,60,70,7000 In this case, I think that it is better to use median instead of using the mean.  CASE 3:    Assume X = 10,20,30,400,500,600,700 In this case, I think it is better to use IQR (Inter Quartile Range)    But I'm stuck with how to decide these hard-limits i.e. which to use in which condition, in general.   I've found a tool working on subjected principle, which takes context-less sample-distribution as input and determines whether mean is close/moderate or against the null-hypothesis.  Find References:-     (For Mean Test)  (For Median Test)   What I'm really looking is a good answer which states how to derive these conclusions. How to work out sqft/m of land coverage? I am currently self teaching myself on qgis whilst volenteering on a project on a river catchment and your help is hugely appreciated!  I need to be able to work out the percentage of land cover or sqft/m coverage. I have all the land uses on as a vector layer over my river catchment.   Many thanks and let me know what other info i need to give as a newbie! "(CRON) info (No MTA installed, discarding output)" error in the syslog