/*This example generates a data set with one variable and 100 records
Each record contains a random number, generated from a uniform distribution, in the range [0:1].
The idea is to create a new data set with the mean value of all the records
START ADaMSoft, copy the script in the command editor window and press F8*/

dataset out=test;
newvar random_value=num;
for (int i=0; i<100; i++)
{
	random_value=RNDUNIFORM();
	output;
};
run;

dataset dict=test out=mean;
newvar mean sum records=num;
retain sum records;
if (ISMISSING(sum)) sum=0;
if (ISMISSING(records)) records=0;
sum=sum+random_value;
records=records+1;
if (LAST_DICT)
{
	mean=sum/records;
	output;
};
keep mean sum records;
run;

/*HOW IT WORKS:
*** Here a new data set is created, it's name will be "test"
dataset out=test;
*** A numerical variable is created, it's name is "random_value"
newvar random_value=num;
*** The operations between the brackets are repeated 100 times
for (int i=0; i<100; i++)
{
	*** The ADaMSoft function RNDUNIFORM() is called and it's return value is copied into the variable "random_value"
	random_value=RNDUNIFORM();
	*** here the record is written in the output data set
	output;
};
run;

*** Here the input data set is accessed and it will be created the result data set called "mean"
dataset dict=test out=mean;
*** Here are defined three new variables, called "mean", "sum" and "records"
newvar mean sum records=num;
*** Here it is specified that, for each record, the values of the variables "sum" and "records" should be retained
retain sum records;
*** Obvioulsy for the first record the values of "sum" and of "records" are null
if (ISMISSING(sum)) sum=0;
if (ISMISSING(records)) records=0;
*** For each record the value of the "sum" is updated with the current value of the variable "random_value"
sum=sum+random_value;
*** For each record the counter of the number of record is updated by adding 1
records=records+1;
*** The next statements will be executed after the last record was accessed
if (LAST_DICT)
{
	*** The mean is... the total sum divided by the number of records
	mean=sum/records;
	*** The idea is to write just this record
	output;
};
*** Here it is specified that we want just these variables
keep mean sum records;
run;*/