rbyexamples.blogspot.com
R by examples: R for Stata users (Part 3)
http://rbyexamples.blogspot.com/2015/07/r-for-stata-users-part-3.html
Thursday, July 2, 2015. R for Stata users (Part 3). We learned how to use R to load datasets, perform simple manipulations, and conduct linear regression. Here, we will learn how to save work, draw scatterplots, handle dates and times, extract substrings, and encode variables. Make sure that you've opened RStudio and loaded the auto dataset. Task #11: Save work. The following command will write a CSV file to RStudio's current working directory:. Writecsv(auto, "edited auto.csv"). And we can then write ou...
rbyexamples.blogspot.com
R by examples: Plotting maps with choroplethr
http://rbyexamples.blogspot.com/2015/07/plotting-maps-with-choroplethr.html
Saturday, July 4, 2015. Plotting maps with choroplethr. According to the below graphic from the Sacramento Bee, Latinos have overtaken whites to become the most populous ethnic group. Let's use the choroplethr package to examine the racial distribution of California counties. Let's start with the preliminaries: installing and loading the package, as well as loading the relevant datasets. We'd also need to load the ggplot2 library, which will come useful in plotting the maps. Consists of three layers:.
rbyexamples.blogspot.com
R by examples: Overview of Machine Learning Techniques in R
http://rbyexamples.blogspot.com/2015/07/overview-of-machine-learning-techniques.html
Sunday, July 12, 2015. Overview of Machine Learning Techniques in R. Whenever we do something as simple as a Google search, we benefit from machine learning. Demand is high for those with machine learning skills - a search of LinkedIn reveals 9,369 results for "machine learning". Subsequent posts will elaborate on these in more detail. September 1, 2015 at 8:52 PM. Thanks for sharing your interesring post. Koyo kaki bamboo vbo original. Harga Grosir Termurah Agen Moment Slimmer. R for Public Health.
rbyexamples.blogspot.com
R by examples: Extracting JSON data in R
http://rbyexamples.blogspot.com/2015/07/extracting-json-data-in-r.html
Monday, July 6, 2015. Extracting JSON data in R. Increasingly, data on the internet is presented in JSON format. For the uninitiated, here's what a JSON file looks like:. Name:"John Smith", timings:[1,2,3]},. Name:"Adam Yu", timings:[3,2,1]},. Name:"Frank Pin", timings:[7,4,3]}. How can R analyze the data appropriately? Let's take a look at a real life example: the salaries of public servants at the City of Chicago. R has three major packages which can analyze JSON data. Of what you need. I say most.
rbyexamples.blogspot.com
R by examples: Linear regression
http://rbyexamples.blogspot.com/2015/07/linear-regression.html
Sunday, July 12, 2015. Let's try regression on the auto dataset. Regfit.full - regsubsets(price ., auto). It doesn't work because by default, exhaustive search is performed. This requires lots of permutations, so you have to set really.big=TRUE if you want this. But let's just make things simpler by carving out a subset of variables:. Autosmall - auto[,c(2,3,5,6,7,8,9,10,11)]. Regfit.full - regsubsets(price . , autosmall). The indicates we want all variables to be considered. For model selection, it'll b...
beckmw.wordpress.com
Sensitivity analysis for neural networks – R is my friend
https://beckmw.wordpress.com/2013/10/07/sensitivity-analysis-for-neural-networks
R is my friend. 039;R challenge is like the Rubik's cube of our people' – Sarah Thompson. Sensitivity analysis for neural networks. And determining importance of model inputs. This post will describe a function for a sensitivity analysis of a neural network. Specifically, I will describe an approach to evaluate the form of the relationship of a response variable with the explanatory variables used in the model. The general goal of a sensitivity analysis is similar to evaluating relative importance. We mi...
quantnews.com
Quant News
http://www.quantnews.com/index.php?last=2369
The latest research and news for quantitative traders. Fast Traders Make a Quick Buck: The Role of Speed in Liquidity Provision. A Bargain Hunter's Dream: High-Priced Stocks. Are expensive, that is, high-priced stocks, in reality the cheap ones from a fundamental perspective? A href=http:/ ssrn.com/abstract=2078535 The Golden Dilemma /a. A href=http:/ ssrn.com/abstract=2148691 An Impressionistic View of the 'Real' Price of Gold Around the World /a . The Term Structure of the Price of Variance Risk. At th...
rbyexamples.blogspot.com
R by examples: Linear Regression in R
http://rbyexamples.blogspot.com/2015/07/linear-regression-in-r.html
Sunday, July 5, 2015. Linear Regression in R. Let's load the auto dataset. And learn regression techniques in more detail. (For those who have not read previous posts, this is a dataset containing information about 74 cars.). Suppose we want to find the relationship between the price and weight of a car. One way to do this is. Priceweight - lm(auto$price auto$weight). Priceweight - lm(price weight, data=auto). Will work as well. We can then visualize the data by. Abline(priceweight, lwd = 5). It might be...
rbyexamples.blogspot.com
R by examples: July 2015
http://rbyexamples.blogspot.com/2015_07_01_archive.html
Sunday, July 12, 2015. Let's try regression on the auto dataset. Regfit.full - regsubsets(price ., auto). It doesn't work because by default, exhaustive search is performed. This requires lots of permutations, so you have to set really.big=TRUE if you want this. But let's just make things simpler by carving out a subset of variables:. Autosmall - auto[,c(2,3,5,6,7,8,9,10,11)]. Regfit.full - regsubsets(price . , autosmall). The indicates we want all variables to be considered. For model selection, it'll b...
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