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johnmoore
Level IV

Random Uniform() keeps giving me the same number

My script is returning random values from Random Uniform(), until I write some results to a data table.  When I write to the table Random Uniform() always returns the same value.   See comments in script below.  Would appreciate any help. 

 

Many thanks, 

John

 

names default to here(1);
clear log();
include("defineVectorClass.jsl");
dtChaos = open("chaos.jmp");
proportionToCorner = 0.5;
A = new object(Vector(column(dtChaos,"x")[1],column(dtChaos,"y")[1]));
B = new object(Vector(column(dtChaos,"x")[2],column(dtChaos,"y")[2]));
C = new object(Vector(column(dtChaos,"x")[3],column(dtChaos,"y")[3]));
triangle = {A,B,C};

dtChaos<<Graph Builder(
	Size( 534, 454 ),
	Show Control Panel( 0 ),
	Show Legend( 0 ),
	Variables( X( :X ), Y( :Y ) ),
	Elements( Points( X, Y, Legend( 3 ) ) )
);

current = new object(Vector(column(dtChaos,"x")[4],column(dtChaos,"y")[4]));
wait(2);
for(i=1,i<1000,i++,
	bill = Random Uniform( 0, 3 );//this is where I am generating random value
	show(randomuniform());
	show(bill);
	corner = triangle[Ceiling( bill )];
	show(corner);
	cornerTemp = corner<<clone;
	show(cornerTemp);
	currentTemp = current<<clone;
	show(currentTemp);
	cornerTemp:sub(currentTemp);
	show(cornerTemp);
	cornerTemp:mult(proportionToCorner);
	show(cornerTemp);
	current:add(cornerTemp);
	show(current);
	newX = current:x;
	newY = current:y;
	column(dtChaos,"X")[1+4]=newX;//the values generated above are random
	column(dtChaos,"Y")[1+4]=newY;//unless these two lines are uncommented, then I get the same value from random uniform()

	wait(2);
	
	
);
1 ACCEPTED SOLUTION

Accepted Solutions
Craige_Hales
Super User

Re: Random Uniform() keeps giving me the same number

(Thanks @EvanMcCorkle  and @danschikore  for puzzling this out before I got in this morning!)

It is a bug in JMP's marker drawing; the easiest way to get your JSL going is to remove the Label state and change it to a color.

Use color rather than labelUse color rather than label

The problem is with the code that is positioning the labels around the data points; it needs a repeatable sequence of random numbers to juggle colliding labels, but it isn't keeping the reset to itself...as you noticed.

 

Another approach that keeps the labels needs a workaround in your JSL:

	r = Random Seed State(); // the following statements make the graph update...
	
	newX = current:x;
	newY = current:y;
	column(dtChaos,"X")[1+4]=newX;
	column(dtChaos,"Y")[1+4]=newY;
	wait(2);
	
	Random Seed State(r);

this captures and restores the random state before and after the markers are drawn. The combination of changing a value in the table and the wait triggers the graph to update.

 

Thanks for the test case; a proper fix is underway.

Craige

View solution in original post

5 REPLIES 5
Craige_Hales
Super User

Re: Random Uniform() keeps giving me the same number

I see the issue, don't know the answer yet.

I'll look at it monday morning.

 @EvanMcCorkle 

 

Craige
Craige_Hales
Super User

Re: Random Uniform() keeps giving me the same number

(Thanks @EvanMcCorkle  and @danschikore  for puzzling this out before I got in this morning!)

It is a bug in JMP's marker drawing; the easiest way to get your JSL going is to remove the Label state and change it to a color.

Use color rather than labelUse color rather than label

The problem is with the code that is positioning the labels around the data points; it needs a repeatable sequence of random numbers to juggle colliding labels, but it isn't keeping the reset to itself...as you noticed.

 

Another approach that keeps the labels needs a workaround in your JSL:

	r = Random Seed State(); // the following statements make the graph update...
	
	newX = current:x;
	newY = current:y;
	column(dtChaos,"X")[1+4]=newX;
	column(dtChaos,"Y")[1+4]=newY;
	wait(2);
	
	Random Seed State(r);

this captures and restores the random state before and after the markers are drawn. The combination of changing a value in the table and the wait triggers the graph to update.

 

Thanks for the test case; a proper fix is underway.

Craige
XanGregg
Staff

Re: Random Uniform() keeps giving me the same number

Another work-around is to turn off the Hide Overlapping Labels preference in the Graphs preferences group. That appears to be the source of the inteference with the random stream.

johnmoore
Level IV

Re: Random Uniform() keeps giving me the same number

Thanks Xan

johnmoore
Level IV

Re: Random Uniform() keeps giving me the same number

Thanks for the quick response.  Labels were not important for the simulation so I just turned them off like you suggested and everything is working great.