Configure Eclipse IDE to work for both 32-bit and 64-bit R

Sometime we need to make Eclipse compatible simultaneously for both 32-bit and 64-bit versions of R. For example, we may have the 64-bit R as the default configuration. However, if we want to run the odbcConnectExcel function which only works under 32-bit scenary, we have to switch the current active configuration to 32-bit R. This tutorial...

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Use Eclipse as IDE for R under Windows

Background Eclipse is an open source Integrated Development Environment (IDE). As with Microsoft's Visual Studio product, Eclipse is programming language-agnostic and supports any language having a suitable plugin for the IDE platform. For Eclipse, the R language plugin is StatET. The StatET plugin enables Eclipse to connect to R. You...

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Import date from Excel spreadsheet into R using RODBC package

Package RODBC can be used not only for ODBC database connectivity, but also for importing Excel spreadsheet data into R, as shown in following R code: library(RODBC) data=odbcConnectExcel(file.choose()) mydata=sqlFetch(data,"Sheet1") odbcClose(data) mydata Here, the odbcConnectExcel establishes a connection to an external Excel spreadsheet. Note: Function 'odbcConnectExcel' is only usable with 32-bit R. Under Eclipse...

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Import data from Microsoft SQL server to R using RODBC package

As preparation, first create an ODBC driver connection for SQL Server by Control Panel >> Administrative Tools >> Data Sources (ODBC) Then import data from SQL server with following R code library(RODBC) conn <- odbcConnect(dsn="ACCPAC 54 SQL",uid="my_ID",pwd="my_PWD") #sqlTables(channel) queryResult <- sqlQuery(conn,...

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Import data from Microsoft SQL server to R using RJDBC package

Environment Windows 7, 64-bit R 2.15.1 (32- & 64-bit) Microsoft SQL Server 2008 Installation & Usage Download JDBC driver from Microsoft ( Link ) and install it so that RJDBC plugin is able to interact with SQL Server database via the Java interface. You can install the driver to a local folder, such as C:\Program Files\Microsoft SQL Server JDBC Driver 3.0 The latest RJDBC release...

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Truncate minute and second timestamp from date value in SQL

Suppose we retrieve a variable 'Valuation_Date' from SQL database and get following number 2012-01-22 00:00:00.000 We can use convert function to truncate minute and second timestamp using the convert function convert(varchar(8), Valuation_Date, 112) then we will get following reault: 201201...

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Matlab tip -- finding the indices of the elements of one array in another

Suppose all elements in array1 are contained in array2, now we want to get the indices of array1's elements in array2. Here is a simple and neat solution, using Matlab's arrayfun function, which applies a function to each element of an array. array1=[1,6,2,3,7]; array2=[3,6]; arrayfun(@(x)find(array1==x,1),array2) The output is: ans =       4    ...

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A beginner's tutorial for R

Some common commands # Quit R q() q(save="no") # Setting the default working directory setwd(file="c:\\AnyDirectory\\") setwd(file="c:/AnyDirectory/") # Get the default working directory getwd() # See which variables are currently in the workspace ls() # Remove a list of variables rm(var1,var2,var3,...) # Remove all objects from workspace rm(list=ls()) # Note: the variables whose names begin with a dot are not listed...

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Control Excel chart position with row and column numbers in Matlab

Sometimes we want to align, in Excel spreadsheet, a chart with a cell which, for example, may contain a label for the chart. We can easily drag (with mouse) the chart to make it aligned with the cell, but it may not be so easy to do this by program. The challenge here is that in Excel spreadsheet a cell position is expressed in row and columns, while a chart position is expressed in points. Depending on the screen resolution,...

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A latex template for writing an technical article

\documentclass[8pt,onecolumn,letterpaper]{article} \usepackage[top=0.5in, bottom=0.5in, left=1.0in, right=1.0in]{geometry} \setlength{\columnseprule}{0.25pt} \usepackage[utf8x]{inputenc} \usepackage{ucs} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \setlength{\parindent}{0in} \setlength\parskip{0.1in} \linespread{1.25} \usepackage{graphicx} \usepackage{color} \usepackage[colorlinks=true, pdfstartview=FitV,...

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Southeast and Gulf Coast electricity markets

Unlike regions with independent power grids, power in the Southern states is provided by integrated power companies. Each of these companies is linked to nearby grids and power can be traded between them. However, because these are still regulated markets, there is little opportunity to trade power within the service area of any of these...

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New England electricity market (ISO-NE)

There is only a single trading hub in the New England region. The price at thsi hub are based on selected nodes around the Boston area. New England has to import fuel for almost all of its power generation requirements. The marginal fuel for the region is natural gas. The bulk of this supply comes from the U.S. Gulf Coast and eastern...

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New York electricity market (NYISO)

The New York power grid is self-contained in the state of New York. The southeastern part of this region the most heavily concentrated areas of demand for electricity in the country: New York City and Long Island. The region is characterized by the flow of low cost power from the northern and western sections of the state into the high...

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Midwest electricity market (MISO)

The Midwest ISO coordinates power for the north-central United States The eastern part of the MISO region is heavily industrialized. The western section of th MISO region is more rural. There are several major trading locations in the region. among them Cinergy Hub is the most influential. From a climate perspective: ...

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Mid-Atlantic electricity market (PJM ISO)

The Mid-Atlantic region contains many large population centers, like Washington D.C., Baltimore, and Philadelphia, on the eastern seaboard. This area formed one of the first independent power grids, the PJM ISO, named after its condtituent states: Pennsylvania, New Jersey, and Maryland.PJM has since expanded to include West Virginia,...

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Pacific northwest electricity market

In most years, the Pacific Northwest sells surplus power into California and the Southwest. About two-thirds of all the electricity in this region comes from hydroelectric production ==> the quantity of surplus power depends heavily on precipitation ==> Water flow in this region directly affects the price of power in California. Melting...

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Desert southwest electricity market

The desert southwest has moderate winter and prolonged hot summers Mush of the year, the area has a surplus of generation capacity and is a major exporter of power to South California. Natural gas is the most common marginal fuel due to the abundant natural gas reserves, but coal and hydropower are relatively common too. The area also...

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California electricity market (CAISO)

California is a heavily populated state that is divided into two major zones: NP-15 and SP-15. Most of the year, the daily temperatures are moderate to warm. However, the dense population and hot summers can cause spikes in the electrical loads due to a demand for air conditioning. One of the major transmission lines, Path-15, bisects...

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Regional power markets in United States

There are three major integrated power grids in the United States: Eastern Interconnect --- east of the Rocky Mountains Western Interconnect --- west of the Rocky Mountains Texas Interconnect --- Texas Inside each interconnection, all of the transmission lines are synchronized ==> allows power to be transported across long distances...

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Heat rate and spark spreads

Heat rates Heat rate represent the efficiency of a power plant to convert fuel into electricity ==> Lower heat rate implies a more efficient power plant. $$\text{Heat Rate}=\frac{\text{Quantity of fuel used}}{\text{Quantity of power produced}}$$ The unit of heat rate is Btu/KWh or MMBtu/MWh, with 1 MMBtu/MWh = 1000 Btu/KWh For...

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Design of electrical trading markets

Spot vs forward power markets The forward power market is where the bulk of speculative tradings occur, while the spot power market is where daily auctions occur. The forward market is open to anyone with sufficient money to meet trading requirements, while the spot market is open only to power providers with the ability to generate power...

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Overview of electricity markets

It is hard to store electricity and expensive to transmit electricity over long distance ==> No unified national electricity market, instead just a collection of small regional markets with their own unique characteristics and regulations.In each market, supply and demand must constantly be matched, resulting in highly volatile prices. Regulations...

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Factors affecting natural gas prices

Natural gas prices are a function of market supply and demand. Because of limited alternatives for natural gas consumption or production in the short run, even small changes in supply or demand over a short period can result in large price movements to bring supply and demand back into balance. See Today in Energy, June 11, 2012 for recent...

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The price of natural gas

The price that residential consumers pay for natural gas has two main parts (all cost components include a number of taxes): Commodity costs — the cost of the natural gas itself, known as the wellhead cost. Transmission and distribution costs — the cost to move the natural gas by pipeline from where it is produced to the customer's local...

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Natural gas consumption in United States

Natural Gas Is a Major Energy Source for the United States About 25% of energy used in the United States came from natural gas in 2011. The United States used 24.37 trillion cubic feet (Tcf) of natural gas in 2011. How Natural Gas Is Used Natural gas is used to produce steel, glass, paper, clothing, brick, electricity, and as an essential...

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