Epib 698e lecture 6
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EPIB 698E Lecture 6. Raul Cruz-Cano Fall 2013. Sorting, Printing and Summarizing Your Data. SAS Procedures (or PROC) perform specific analysis or function, produce results or reports Eg: Proc Print data =new; run; All procedures have required statements, and most have optional statements

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EPIB 698E Lecture 6

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Epib 698e lecture 6

EPIB 698E Lecture 6

Raul Cruz-Cano

Fall 2013


Sorting printing and summarizing your data

Sorting, Printing and Summarizing Your Data

  • SAS Procedures (or PROC) perform specific analysis or function, produce results or reports

  • Eg: Proc Print data =new; run;

  • All procedures have required statements, and most have optional statements

  • All procedures start with the key word “PROC”, followed by the name of the procedure, such as PRINT, or contents

  • Options, if there are any, follow the procedure name

  • Data=data_name options tells SAS which dataset to use as an input for this procedure. NOTE: if you skip it, SAS will use the most recently created dataset, which is not necessary the same as the mostly recently used data.


By statement

BY statement

  • The BY statement is required for only one procedure, Proc sort

    PROC Sort data = new;

    By gender;

    Run;

  • For all the other procedures, BY is an optional statement, and tells SAS to perform analysis for each level of the variable after the BY statement, instead of treating all subjects as one group

    Proc Print data =new;

    By gender;

    Run;

  • All procedures, except Proc sort, assumes you data are already sorted by the variables in your BY statement


Proc sort

PROC Sort

  • Syntax

    Proc Sort data =input_data_name out =out_data_name ;

    By variable-1 … variable-n;

  • The variables in the by statement are called by variables.

  • With one by variable, SAS sorts the data based on the values of that variable

  • With more than one variable, SAS sorts observations by the first variable, then by the second variable within the categories of the first variable, and so on

  • The DATA option specify the input data set. Without the DATA option, SAS will use the most recently created data set.


Proc sort1

PROC Sort

  • By default, SAS sorts data in ascending order, from the lowest to the highest value or from A to Z. To have the ordered reversed, you can add the keyword DESCENDING before the variable you want to use the highest to the lowest order or Z to A order

  • The NODUPKEY option tells SAS to eliminate any duplicate observations that have the same values for the BY variables


Proc sort2

PROC Sort

  • Example: The sealife.txt contains information on the average length in feet of selected whales and sharks. We want to sort the data by the family and length

    Name Family Length

    beluga whale 15

    whale shark 40

    basking shark 30

    gray whale 50

    mako shark 12

    sperm whale 60

    dwarf shark .5

    whale shark 40

    humpback . 50

    blue whale 100

    killer whale 30


Proc sort3

PROC Sort

  • Example: The sealife.txt contains information on the average length in feet of selected whales and sharks. We want to sort the data by the family and length

    Name Family Length

    beluga whale 15

    whale shark 40

    basking shark 30

    gray whale 50

    mako shark 12

    sperm whale 60

    dwarf shark .5

    whale shark 40

    humpback . 50

    blue whale 100

    killer whale 30


Proc sort4

PROC Sort

DATA marine;

INFILE 'F:\sealife.txt';

INPUT Name $ Family $ Length;

run;

* Sort the data;

PROCSORTDATA = marine OUT = seasort

NODUPKEY;

BY Family DESCENDING Length;

run;


Title and footnote statement

Title and Footnote statement

  • Title and Footnote statements are global statements, and are not technically part of any step.

  • You can put them anywhere in your program; but since they apply to the procedure output, it is usually make sense to put them with the procedure

  • Syntax

    Title ‘This is a title for this procedure’

    Footnote ‘This is the footnote for this procedure’;

  • To cancel the current title or footnote, use the following null statement:

    Title;

    Footnote;


Label statement

Label Statement

  • The label statement can create descriptive labels, up to 256 characters long, for each variable

  • Eg:

    Label Shipdate = ‘Date merchandise was shipped’;

    ID =‘Identification number of subject’;

  • When a label statement is used in a data step, the labels become part of the data set; but when used in a PROC step, the labels stay in effect only for the duration of that step

If you want to see the labels in a proc print you have to use the option label.


Epib 698e lecture 6

DATA marine;

INFILE 'C:\sealife.txt';

INPUT Name $ Family $ Length;

Label Family = "Famili name"

Length="subject lenght“

;

run;

proc print data =marine label;

run;


Proc format statement

PROC Format statement

  • The PROC FORMAT procedure allows you to create your own formats. It is useful when you use coded data.

  • The Proc format procedure creates formats what will later be associated with variables in a FORMAT statement

  • Syntax of the PROC FORMAT:

    PROC FORMAT;

    Value name range-1 =‘formated-text-1’

    range-2 =‘formated-text-2’

    range-n =‘formated-text-n’;

  • Name is the name of the format you are creating; if the format is for character data, the you need to use $name instead of name. In addition the name can not be the name of an existing format


Proc format statement1

PROC Format statement

  • Each range is the value of the variable that is assigned to the text given in the quotation marks

  • The text can be up to 32,767 characters long, but some procedures print only the first 8 to 16 characters

  • The following are some examples of valid range specifications:

    ‘A’=‘Asian’; character values must be put in quotation marks

    1,3,5,7,9=‘ODD’; with more than one value in the range, separate

    them with comma or hyphen (-);

    5000-high=‘high price’; the key word high and low can be used in

    ranges to indicate the lowest and highest

    non-missing values for the variable


Proc format statement2

PROC Format statement

  • Here is a survey about subject’s preference of car colors. The data contains subject’s age, sex (coded as 1 for male and 2 for female), annual income, and preferred car color (yellow, green, blue, and white). Here are the data:

    age sex income color

    19 1 14000 Y

    45 1 65000 G

    72 2 35000 B

    31 1 44000 Y

    58 2 83000 W


Epib 698e lecture 6

DATA carsurvey;

INFILE ‘C:\car.txt';

INPUT Age Sex Income Color $ ;

run;

PROCFORMAT;

VALUE gender 1 = 'Male’

2 = 'Female';

VALUE agegroup 13 -< 20 = 'Teen'

20 -< 65 = 'Adult'

65 - HIGH = 'Senior';

VALUE $col 'W' = 'Moon White'

'B' = 'Sky Blue'

'Y' = 'Sunburst Yellow'

'G' = ‘Green';

run;

PROCPRINTDATA = carsurvey;

FORMAT Sex gender. Age agegroup.

Color $col. Income DOLLAR8.;

RUN;


Subsetting in procedures with a where statement

Subsetting in procedures with a where statement

  • The WHERE statement tells a procedure to use a subset of data

  • It is an optional statement for any PROC step

  • Unlike subsetting in the DATA step, using a WHERE statement in a procedure does not create a new data set

  • The basic form is

    Where condition; (eg : where gender =‘female’;)


Subsetting in procedures with a where statement1

Subsetting in procedures with a where statement

  • A data set contains information about well-known painters:

    Name StyleNation of origin

    Mary Cassatt Impressionism U

    Paul Cezanne Post-impressionism F

    Edgar Degas Impressionism F

    Paul Gauguin Post-impressionism F

    Claude Monet Impressionism F

    Pierre Auguste Renoir Impressionism F

    Vincent van Gogh Post-impressionism N

  • Goal: we want a list of impressionist painters


Epib 698e lecture 6

DATA style;

INFILE‘C:\style.txt';

INPUT Name $ 1-21 style $ 23-40 Origin $ 42;

RUN;

PROCPRINTDATA = style;

WHERE style = 'Impressionism';

TITLE'Major Impressionist Painters';

FOOTNOTE'F = France N = Netherlands U = US';

RUN;


Summarizing you data with proc means

Summarizing you data with PROC MEANS

  • The proc means procedure provide simple statistics on numeric variables. Syntax: Proc means options ;

  • List of simple statistics can be produced by proc means:

    MAX: the maximum value

    MIN: the minimum value

    MEAN: the mean

    N : number of non-missing values

    STDDEV: the standard deviation

    NMISS: number of missing values

    RANGE: the range of the data

    SUM: the sum

    MEDIAN: the median

DEFAULT


Proc means

Proc means

  • Options of Proc means:

  • By variable-list : perform analysis for each level of the variables in the list. Data needs to be sorted first

  • Var variable list: specifies which variables to use in the analysis


Proc means1

Proc means

  • A wholesale nursery is selling garden flowers, they want to summarize their sales figures by month. The data is as follows:

    IDDate Lily SnapDragon Marigold

    756-01 05/04/2001 120 80 110

    756-01 05/14/2001 130 90 120

    834-01 05/12/2001 90 160 60

    834-01 05/14/2001 80 60 70

    901-02 05/18/2001 50 100 75

    834-01 06/01/2001 80 60 100

    756-01 06/11/2001 100 160 75

    901-02 06/19/2001 60 60 60

    756-01 06/25/2001 85 110 100


Epib 698e lecture 6

DATA sales;

INFILE 'C:\Flowers.txt';

INPUT CustomerID $ @9 SaleDate MMDDYY10. Lily SnapDragon Marigold;

Month = MONTH(SaleDate);

RUN;

PROCSORT DATA = sales;

BY Month;

RUN;

* Calculate means by Month for flower sales;

PROCMEANS DATA = sales;

BY Month;

VAR Lily SnapDragon Marigold;

TITLE 'Summary of Flower Sales by Month';

RUN;


Output statement

OUTPUT statement

  • The SAS data set created by the output statement will contain all the variables defined in the output statistic list; any variables in a BY or CLASS statement, plus two new variables: _TYPE_ and _FREQ_

  • Without BY or CLASS statement, the data will have just one observation

  • If there is a BY statement, the data will have one observation for each level of the BY group

  • CLASS statements produce one observation for each level of interaction of the class variables

  • The value _TYPE_depends on the level of interactions of the CLASS statement.

  • _TYPE_= 0 is the grand total


Output statement of the proc means

OUTPUT statement of the PROC MEANS

  • We can use the OUTPUT statement to write summary statistics in a SAS data set.

  • Syntax

    OUTPUT out =data_name output-statistic-list;

  • Eg:

    * Calculate means by Month for flower sales;

    PROCMEANS DATA = sales;

    OUTPUT OUT= values;

    BY Month;

    VAR Lily SnapDragon Marigold;

    TITLE 'Summary of Flower Sales by Month';

    RUN;

  • In the output data set new1, we have two means for age and BMI respectively. The variable names are mean_age mean_BMI respectively.

  • Be careful with the output format, it might not look as the output of the proc.


Epib 698e lecture 6

data report;

set values ( keep= Lily SnapDragon _STAT_ );

if _STAT_ ="MIN" or _STAT_="MAX";

run;


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