Tutorial by Examples: d

A random forest is a meta estimator that fits a number of decision tree classifiers on various sub-samples of the dataset and use averaging to improve the predictive accuracy and control over-fitting. A simple usage example: Import: from sklearn.ensemble import RandomForestClassifier Define tr...

git blame <file> will show the file with each line annotated with the commit that last modified it.

One of the uses of recursion is to navigate through a hierarchical data structure, like a file system directory tree, without knowing how many levels the tree has or the number of objects on each level. In this example, you will see how to use recursion on a directory tree to find all sub-directorie...

Because LINQ uses deferred execution, we can have a query object that doesn't actually contain the values, but will return the values when evaluated. We can thus dynamically build the query based on our control flow, and evaluate it once we are finished: IEnumerable<VehicleModel> BuildQuery(i...

While RODBC is restricted to Windows computers with compatible architecture between R and any target RDMS, one of its key flexibilities is to work with Excel files as if they were SQL databases. require(RODBC) con = odbcConnectExcel("myfile.xlsx") # open a connection to the Excel file s...

First need to create a final static logger object: final static Logger logger = Logger.getLogger(classname.class); Then, call logging methods: //logs an error message logger.info("Information about some param: " + parameter); // Note that this line could throw a NullPointerException!...

Python has a variety of command-line switches which can be passed to py. These can be found by performing py --help, which gives this output on Python 3.4: Python Launcher usage: py [ launcher-arguments ] [ python-arguments ] script [ script-arguments ] Launcher arguments: -2 : Launch ...

Public Sub DoLoop() Dim entry As String entry = "" 'Equivalent to a While loop will ask for strings until "Stop" in given 'Prefer using a While loop instead of this form of Do loop Do While entry <> "Stop" entry = InputBox("...

Sometimes you need to keep a linear (non-branching) history of your code commits. If you are working on a branch for a while, this can be tricky if you have to do a regular git pull since that will record a merge with upstream. [alias] up = pull --rebase This will update with your upstream so...

Postfix increment X++ will add 1 to x var x = 42; x++; Console.WriteLine(x); // 43 Postfix decrement X-- will subtract one var x = 42 x--; Console.WriteLine(x); // 41 ++x is called prefix increment it increments the value of x and then returns x while x++ returns the value of x and the...

You have a local vagrant box that you want to upload to Amazon AWS. First, you need to create a .box file: vagrant package --base my-virtual-machine This step should take a while depending on the size of your image. Then, you need to get the .vmdk image from the .box file: gunzip -S .box packag...

Predefined operators according to ISO/IEC 13211-1 and 13211-2: PriorityTypeOperator(s)Use1200xfx:- -->1200fx:- ?-Directive, query1100xfy;1050xfy->1000xfy','900fy\+700xfx= \\=Term unification700xfx== \\== @< @=< @> @>=Term comparison700xfx=..700xfxis =:= =\= < > =<...

In Prolog, custom operators can be defined using op/3: op(+Precedence, +Type, :Operator) Declares Operator to be an operator of a Type with a Precedence. Operator can also be a list of names in which case all elements of the list are declared to be identical operators. Precedence is an in...

GridPane lays out its children within a flexible grid of rows and columns. Children of the GridPane A child may be placed anywhere within the GridPane and may span multiple rows/columns (default span is 1) and its placement within the grid is defined by it's layout constraints: ConstraintDescript...

Introduce environment variable VAGRANT_DEFAULT_PROVIDER export VAGRANT_DEFAULT_PROVIDER=vmware_fusion

Vagrant.configure("2") do |config| # ... other config up here config.vm.provider "vmware_fusion" end

vagrant up --provider docker

Instead of the usual loosely typed: @Html.ActionLink("Log in", "UserController", "LogIn") You can now make action links strongly typed: @Html.ActionLink("Log in", @typeof(UserController), @nameof(UserController.LogIn)) Now if you want to refactor your ...

#!/bin/bash NO_SNAPSHOTS="No snapshots have been taken yet" SNAPSHOT_OUTPUT=$(vagrant snapshot list | grep "${NO_SNAPSHOTS}") if [ -z "${SNAPSHOT_OUTPUT}" ]; then echo "Found some snapshots, going to remove them" for SNAPSHOT in $(vagrant snap...

NSString *testString = @"There are 42 sheep and 8672 cows."; NSError *error = nil; NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(\\d+)" options:NSRegularExpressionCaseIns...