Generating random numbers with a trend to make data appear more realistic in some scenarios. 50% chance for a direction change.

example.cfm

<cfscript>
	//to initialize to a random number instead of 50, set last to ""
	last = 50;
	for(var i = 1; i <= 100; i++){
		last = trendingRandom( 0, 100, 12, last );
		writeOutput( "#last#<br/>" );
	}
</cfscript>

gistfile1.cfc

function trendingRandom(rangeMin, rangeMax, volatility = 1, last = ""){
	/* 
		volatility is an integer between 1 and 100 that indicates how wild 
		the swings should be. 12 is a good place to start. 
	*/
	if ( last == "" ){
		return randRange( rangeMin, rangeMax );
	}
	var direction = (randRange(0,1) == 0) ? -1 : 1;
	volatility = randRange(1, volatility) / 100;
	var diff = direction * volatility * last;
	var computed = round(last + diff);
	return Max( rangeMin, Min(rangeMax, computed) );
}