Posts Tagged ‘ Getting Started ’

Read data into vectors or into a matrix: Which is better?

February 8, 2016
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Read data into vectors or into a matrix: Which is better?

In the SAS/IML language, you can read data from a SAS data set into a set of vectors (each with their own name) or into a single matrix. Beginning programmers might wonder about the advantages of each approach. When should you read data into vectors? When should you read data […] The post Read data into vectors or into a matrix: Which is better? appeared first on The DO Loop.

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Group processing in SAS: The NOTSORTED option

February 1, 2016
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Group processing in SAS: The NOTSORTED option

Novice SAS programmers quickly learn the advantages of using PROC SORT to sort data, followed by a BY-group analysis of the sorted data. A typical example is to analyze demographic data by state or by ZIP code. A BY statement enables you to produce multiple analyses from a single procedure […] The post Group processing in SAS: The NOTSORTED option appeared first on The DO Loop.

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What is a moving average?

January 25, 2016
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What is a moving average?

A moving average (also called a rolling average) is a statistical technique that is used to smooth a time series. Moving averages are used in finance, economics, and quality control. You can overlay a moving average curve on a time series to visualize how each value compares to a rolling […] The post What is a moving average? appeared first on The DO Loop.

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Create a SAS macro variable that contains a list of values

January 18, 2016
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Create a SAS macro variable that contains a list of values

Parameters in SAS procedures are specified a list of values that you manually type into the procedure syntax. For example, if you want to specify a list of percentile values in PROC UNIVARIATE, you need to type the values into the PCTLPTS= option as follows: proc univariate data=sashelp.cars noprint; var […] The post Create a SAS macro variable that contains a list of values appeared first on The DO Loop.

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Compute a weighted mean in SAS

January 6, 2016
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Compute a weighted mean in SAS

Weighted averages are all around us. Teachers use weighted averages to assign a test more weight than a quiz. Schools use weighted averages to compute grade-point averages. Financial companies compute the return on a portfolio as a weighted average of the component assets. Financial charts show (linearly) weighted moving averages […] The post Compute a weighted mean in SAS appeared first on The DO Loop.

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Tabulate counts when there are unobserved categories

October 7, 2015
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Tabulate counts when there are unobserved categories

Suppose that you are tabulating the eye colors of students in a small class (following Friendly, 1992). Depending upon the ethnic groups of these students, you might not observe any green-eyed students. How do you put a 0 into the table that summarizes the number of students who have each […] The post Tabulate counts when there are unobserved categories appeared first on The DO Loop.

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Ten "one-liners" that create test matrices for statistical programmers

September 28, 2015
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Ten "one-liners" that create test matrices for statistical programmers

You've had a long day. You've implemented a custom algorithm in the SAS/IML language. But before you go home, you want to generate some matrices and test your program. If you are like me, you prefer a short statement—one line would be best. However, you also want the flexibility to […] The post Ten "one-liners" that create test matrices for statistical programmers appeared first on The DO Loop.

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Excluding variables: Read all but one variable into a matrix

September 21, 2015
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Excluding variables: Read all but one variable into a matrix

Dear Rick, I have a data set with 1,001 numerical variables. One variable is the response, the others are explanatory variable. How can I read the 1,000 explanatory variables into an IML matrix without typing every name? That's a good question. You need to be able to perform two sub-tasks: […] The post Excluding variables: Read all but one variable into a matrix appeared first on The DO Loop.

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Those tricky PERCENT formats

August 10, 2015
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Those tricky PERCENT formats

When using SAS to format a number as a percentage, there is a little trick that you need to remember: the width of the formatted value must include room for the decimal point, the percent sign, and the possibility of two parentheses that indicate negative values. The field width must […] The post Those tricky PERCENT formats appeared first on The DO Loop.

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Convert a vector to a string

July 27, 2015
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Convert a vector to a string

Base SAS contains many functions for processing strings, and you can call these functions from within a SAS/IML program. However, sometimes a SAS/IML programmer needs to process a vector of strings. No problem! You can call most Base SAS functions with a vector of parameters. I have previously written about […] The post Convert a vector to a string appeared first on The DO Loop.

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