Tutorial by Examples: u

A feature that has near zero variance is a good candidate for removal. You can manually detect numerical variance below your own threshold: data("GermanCredit") variances<-apply(GermanCredit, 2, var) variances[which(variances<=0.0025)] Or, you can use the caret package to find...

If a feature is largely lacking data, it is a good candidate for removal: library(VIM) data(sleep) colMeans(is.na(sleep)) BodyWgt BrainWgt NonD Dream Sleep Span Gest 0.00000000 0.00000000 0.22580645 0.19354839 0.06451613 0.06451613 0.06451613 Pred ...

Closely correlated features may add variance to your model, and removing one of a correlated pair might help reduce that. There are lots of ways to detect correlation. Here's one: library(purrr) # in order to use keep() # select correlatable vars toCorrelate<-mtcars %>% keep(is.numeric) ...

By default all enum values are resolved to numbers. Let's say if you have something like enum MimeType { JPEG, PNG, PDF } the real value behind e.g. MimeType.PDF will be 2. But some of the time it is important to have the enum resolve to a different type. E.g. you receive the value fr...

Create groovy file by path $JENKINS_HOME/init.groovy.d/basic-security.groovy In Ubuntu 16 Jenkins home directory places in /var/lib/jenkins Place in file next code #!groovy import jenkins.model.* import hudson.security.* def instance = Jenkins.getInstance() def hudsonRealm = new...

Open Jenkins default config file and add in JAVA_ARGS next key -Djenkins.install.runSetupWizard=false In Ubuntu 16 default file places in /etc/default/jenkins Create groovy file by path $JENKINS_HOME/init.groovy.d/basic-security.groovy In Ubuntu 16 Jenkins home directory places in /var/li...

(This assumes MySQL has been installed and that sudo is being used.) Generating a CA and SSL keys Make sure OpenSSL and libraries are installed: apt-get -y install openssl apt-get -y install libssl-dev Next make and enter a directory for the SSL files: mkdir /home/ubuntu/mysqlcerts cd /home...

Using canvas elements HTML provides the canvas element for building raster-based images. First build a canvas for holding image pixel information. var canvas = document.createElement('canvas'); canvas.width = 500; canvas.height = 250; Then select a context for the canvas, in this case two-di...

The web server serves the user based on the request sent by the browser but how the user will tell the browser what he/she is looking for, that's when we need URL. Every web page on the internet has got a URL that can be bookmarked, copied, shared, and saved for future reference. In single page Back...

To externalise a distributed systems configuration Spring Cloud Config provides server and client-side support needed for externalising and centralising your configuration. To get started quickly you could use Spring Initializr to bootstrap your server. Add the Config Server dependency to automatic...

To get started quickly you could use Spring Initializr to bootstrap your client. Add the Config Client to automatically generate a project with the needed dependencies. Or you could add the dependency manually to an existing Spring Cloud application. <dependency> <groupId>org.spri...

Detailed instructions on getting lambda set up or installed.

Returns the ‘site_url’ option with the appropriate protocol (https://) <?php echo site_url(); ?> Output http://www.example.com

Detailed instructions on getting elastic-beanstalk set up or installed.

Maximum Path Sum is an algorithm to find out a path such that sum of element(node) of that path is greater than any other path. For example, let's we have a we a triangle as shown below. 3 7 4 2 4 6 8 5 9 3 In above triangle, find the maximum path which has ma...

Using ls() as a filter can sometimes provide produce odd results. If you accidentally forget to pass a filter argument and call ls() with no arguments, you will get a list of every node in the Maya scene: cmds.ls() # [u'time1', u'sequenceManager1', u'hardwareRenderingGlobals', u'renderPartition...

It is common to use a background Thread for doing network operations or long running tasks, and then update the UI with the results when needed. This poses a problem, as only the main thread can update the UI. The solution is to use the runOnUiThread() method, as it allows you to initiate code exe...

PS1 is the normal system prompt indicating that bash waits for commands being typed in. It understands some escape sequences and can execute functions or progams. As bash has to position the cursor after the displayes prompt, it needs to know how to calculate the effective length of the prompt strin...

Once you have package control installed, it is super easy to install any plugin, theme, color scheme, syntax that you want! plugin: perform an action (compile your less code into css for example) theme: change the entire skin of sublime text (tabs, sidebar, command palette, etc) color scheme: c...

To get a shorter version of the Null or Empty check, use an "= Nothing" comparison. Iif(Fields!UserEmail.Value = Nothing, "Null or Empty", "Not Null or Empty") The "= Nothing" will check simultaneously against Null or Empty, giving a more compact expressio...