Posts Tagged ‘ Data Analysis ’

Finding observations that match a target value

March 18, 2015
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Finding observations that match a target value

Imagine that you have one million rows of numerical data and you want to determine if a particular "target" value occurs. How might you find where the value occurs? For univariate data, this is an easy problem. In the SAS DATA step you can use a WHERE clause or a […] The post Finding observations that match a target value appeared first on The DO Loop.

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Analyzing the first 10 million digits of pi: Randomness within structure

March 12, 2015
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Analyzing the first 10 million digits of pi: Randomness within structure

Saturday, March 14, 2015, is Pi Day, and this year is a super-special Pi Day! This is your once-in-a-lifetime chance to celebrate the first 10 digits of pi (π) by doing something special on 3/14/15 at 9:26:53. Apologies to my European friends, but Pi Day requires that you represent dates […] The post Analyzing the first 10 million digits of pi: Randomness within structure appeared first on The DO Loop.

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Plotting multiple time series in SAS/IML (Wide to Long, Part 2)

February 27, 2015
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Plotting multiple time series in SAS/IML (Wide to Long, Part 2)

I recently wrote about how to overlay multiple curves on a single graph by reshaping wide data (with many variables) into long data (with a grouping variable). The implementation used PROC TRANSPOSE, which is a procedure in Base SAS. When you program in the SAS/IML language, you might encounter data […]

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Plotting multiple series: Transforming data from wide to long

February 25, 2015
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Plotting multiple series: Transforming data from wide to long

Data. To a statistician, data are the observed values. To a SAS programmer, analyzing data requires knowledge of the values and how the data are arranged in a data set. Sometimes the data are in a "wide form" in which there are many variables. However, to perform a certain analysis […]

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The advantages of using count() to get N-way frequency tables as data frames in R

The advantages of using count() to get N-way frequency tables as data frames in R

Introduction I recently introduced how to use the count() function in the “plyr” package in R to produce 1-way frequency tables in R.  Several commenters provided alternative ways of doing so, and they are all appreciated.  Today, I want to extend that tutorial by demonstrating how count() can be used to produce N-way frequency tables […]

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How to Get the Frequency Table of a Categorical Variable as a Data Frame in R

How to Get the Frequency Table of a Categorical Variable as a Data Frame in R

Introduction One feature that I like about R is the ability to access and manipulate the outputs of many functions.  For example, you can extract the kernel density estimates from density() and scale them to ensure that the resulting density integrates to 1 over its support set. I recently needed to get a frequency table of […]

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Popular posts from The DO Loop in 2014

January 2, 2015
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Popular posts from The DO Loop in 2014

I published 118 blog posts in 2014. This article presents my most popular posts from 2014 and late 2013. 2014 will always be a special year for me because it was the year that the SAS University Edition was launched. The University Edition means that SAS/IML is available to all […]

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Exploratory Data Analysis – All Blog Posts on The Chemical Statistician

Exploratory Data Analysis – All Blog Posts on The Chemical Statistician

This series of posts introduced various methods of exploratory data analysis, providing theoretical backgrounds and practical examples.  Fully commented and readily usable R scripts are available for all topics for you to copy and paste for your own analysis!  Most of these posts involve data visualization and plotting, and I include a lot of detail and […]

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Initial steps towards reproducible research

December 4, 2014
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Initial steps towards reproducible research

In anticipation of next week’s Reproducible Science Hackathon at NESCent, I was thinking about Christie Bahlai’s post on “Baby steps for the open-curious.” Moving from Ye Olde Standard Computational Science Practice to a fully reproducible workflow seems a monumental task, but partially reproducible is better than not-at-all reproducible, and it’d be good to give people […]

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Resampling and permutation tests in SAS

November 21, 2014
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Resampling and permutation tests in SAS

My colleagues at the SAS & R blog recently posted an example of how to program a permutation test in SAS and R. Their SAS implementation used Base SAS and was "relatively cumbersome" (their words) when compared with the R code. In today's post I implement the permutation test in […]

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