Tutorial by Examples: df

READ data-file

To separate API logic from the component, we are creating the API client as a separate class. This example class makes a request to Wikipedia API to get random wiki articles. import { Http, Response } from '@angular/http'; import { Injectable } from '@angular/core'; import { Observabl...

To get the list of functions within package dplyr, we first must load the package: library(dplyr) ls("package:dplyr")

UNLOCK filename-1 RECORDS

This example covers some advanced features and use-cases for Exceptions. Examining the callstack programmatically Java SE 1.4 The primary use of exception stacktraces is to provide information about an application error and its context so that the programmer can diagnose and fix the problem. Som...

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) ...

The [record][1] library provides the ability to create compound terms with named fields. The directive :- record/1 <spec> compiles to a collection of predicates that initialize, set and get fields in the term defined by <spec>. For example, we can define a point data structure with nam...

Firebase provides backend as a service, as applciation developer you do not have an option to have backend code. This example shows how using firebase queue, create backend which will operate on the top of firebase database and serve as a backend for your frontend application. Before getting into ...

for ([declaration-or-expression]; [expression2]; [expression3]) { /* body of the loop */ } In a for loop, the loop condition has three expressions, all optional. The first expression, declaration-or-expression, initializes the loop. It is executed exactly once at the beginning of the lo...

Best way to connect amazon redshift using JDBC , Use proper driver as per version http://docs.aws.amazon.com/redshift/latest/mgmt/configure-jdbc-connection.html Step-1: npm install jdbc Step-2: var JDBC = require('jdbc'); var jinst = require('jdbc/lib/jinst'); // isJvmCreated will be true afte...

The Required column of the schema indicates whether this field is required to save the record. If this column says true, then you will need to provide a value for this field when saving any record of this type.

std::vector<int> primes = {2, 3, 5, 7, 11, 13}; for(auto prime : primes) { std::cout << prime << std::endl; }

variables this local arguments

var express = require('express'); var path = require('path'); var favicon = require('serve-favicon'); var app = express(); app.use(favicon(__dirname + '/public/img/favicon.ico')); app.use(express.static(path.join(__dirname, 'public'))); app.listen(3000, function() { console.log("...

int x, y; bool ready = false; void init() { x = 2; y = 3; ready = true; } void use() { if (ready) std::cout << x + y; } One thread calls the init() function while another thread (or signal handler) calls the use() function. One might expect that the use() function ...

How to read a netCDF file (.nc) with python gdal ? import gdal # Path of netCDF file netcdf_fname = "/filepath/PREVIMER_WW3-GLOBAL-30MIN.nc" # Specify the layer name to read layer_name = "hs" # Open netcdf file.nc with gdal ds = gdal.Open("NETCDF:{0}:{1}".f...

Viridis (named after the chromis viridis fish) is a recently developed color scheme for the Python library matplotlib (the video presentation by the link explains how the color scheme was developed and what are its main advantages). It is seamlessly ported to R. There are 4 variants of color scheme...

# imports import weka.core.converters.ConverterUtils.DataSource as DS import weka.filters.Filter as Filter import weka.filters.unsupervised.attribute.Remove as Remove import os # load data data = DS.read(os.environ.get("MOOC_DATA") + os.sep + "iris.arff") # remove clas...

As an example, lets us look at a Wordpress container The Dockerfile begins with FROM php:5.6-apache so we go to the Dockerfile abovementioned https://github.com/docker-library/php/blob/master/5.6/apache/Dockerfile and we find FROM debian:jessie So this means that we a security patch appears f...

Reading from an input port can be done in many ways. We can use the read method used by the REPL. It will read and interpret space separated expressions. Taking the example from the string port above. We can read from the port like this: (define p (open-input-string "(a . (b . (c . ()))) 3...