✅ All About PROC SUMMARY in SAS: A Comprehensive Guide with Practical Examples

📘 Introduction

PROC SUMMARY in SAS is a powerful procedure used to generate summary statistics for numeric variables. It is often considered functionally equivalent to PROC MEANS but with more flexibility in generating customized outputs and silent summaries.

In this guide, you'll learn:

• Complete syntax of PROC SUMMARY
• All available options and statements
• Grouped examples
• How it differs from PROC MEANS
• Output datasets and tips

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🛠 Syntax of PROC SUMMARY

PROC SUMMARY <options>;
  VAR variable(s);
  CLASS variable(s);
  BY variable(s);
  OUTPUT OUT=dataset <stat-options>;
RUN;

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⚙️ Common Options in PROC SUMMARY

Option	Description
DATA=	Specifies the input dataset
N	Count of non-missing values
MEAN	Mean or average value
STD	Standard deviation
MIN	Minimum value
MAX	Maximum value
SUM	Total sum
MAXDEC=	Maximum number of decimals
NWAY	Outputs only rows with all CLASS variables present
CHARTYPE	Adds a TYPE variable to output

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📄 Statements in PROC SUMMARY

Statement	Purpose
VAR	Specifies numeric variables to analyze
CLASS	Group summary statistics by categorical variables
BY	BY-group processing; data must be sorted
OUTPUT	Outputs summary statistics to a dataset

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✅ PROC SUMMARY vs PROC MEANS

Feature	PROC MEANS	PROC SUMMARY
Displays output	Yes (default)	No (unless PRINT)
Flexibility	Moderate	High
Use in production	For display/review	For data pipelines
Output dataset	Optional	Common

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🧪 Examples of PROC SUMMARY

Example 1: Basic Summary Statistics

proc summary data=sashelp.class print;
run;

Note: Use PRINT to display output.

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Example 2: Specifying Variables

proc summary data=sashelp.class print;
  var height weight;
run;

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Example 3: Using CLASS Statement

proc summary data=sashelp.class print;
  class sex;
  var height weight;
run;

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Example 4: Creating Output Dataset

proc summary data=sashelp.class n mean maxdec=1;
  class sex;
  var height weight;
  output out=summary_stats;
run;

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Example 5: Custom Output Variable Names

proc summary data=sashelp.class;
  class sex;
  var weight;
  output out=summary_data
    mean=mean_weight
    max=max_weight
    min=min_weight;
run;

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Example 6: Using BY Statement (sorted data)

proc sort data=sashelp.class out=sorted;
  by sex;
run;

proc summary data=sorted print;
  by sex;
  var height;
run;

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🔄 Output Options in PROC SUMMARY

You can customize the summary stats by combining the following keywords in the OUTPUT statement:

Keyword	Description
N=	Assigns name to N (count)
MEAN=	Assigns name to mean
STD=	Standard deviation
SUM=	Assigns name to sum
MIN=	Assigns name to minimum
MAX=	Assigns name to maximum

Example:

output out=myout n=n_obs mean=avg std=stdev;

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🧠 Tips for PROC SUMMARY

• Always use PRINT if you want to display results.
• Use NWAY if you need only fully classified combinations.
• Use meaningful output variable names with =.
• Great for creating reusable summary datasets.

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📦 Summary Table

Feature	Description
Primary Use	Summary statistics
Shows Output	No (by default)
Supports Groups	Yes (CLASS or BY)
Custom Output	Yes (OUTPUT statement)
Output Dataset	Yes
Flexible Output	Highly customizable

 

Keywords: PROC SUMMARY SAS, SAS summary statistics, SAS aggregate data, PROC SUMMARY vs PROC MEANS, output statistics SAS, SAS class by var output