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Weibull distribution behaviour

martin_snogdahl

Community Trekker

Joined:

Aug 17, 2016

Hi there,

I have noticed some 'weird' behavior of the Weibull distribution using the simulator in the profiler platform. For narrow distributions, meaning large beta, the distribution seems to split down the middle. I am guessing this is not the normal behavior of a Weibull distribution. The output of a simulation seems to be unaffected by the weird behavior, so it might just be a graphical issue. Has anyone else noticed this behavior? Is there a bug here?


Profiler example:

12852_pastedImage_1.png

Simulation output:

Code:

Table 1 = New Table( "Table 1",

  Add Rows( 1 ),

  New Column( "p1", Numeric, "Continuous", Format( "Best", 12 ), Set Values( [3] ) ),

  New Column( "p2", Numeric, "Continuous", Format( "Best", 12 ), Set Values( [3] ) ),

  New Column( "model",

  Numeric,

  "Continuous",

  Format( "Best", 12 ),

  Formula( :p1 ^ 2 + :p2 ^ 2 ),

  Set Selected

  ),

  Set Row States( [1] )

);

Profiler(

  Y( :model ),

  Profiler(

  1,

  Term Value(

  p1( 3, Min( 2.8 ), Max( 3.2 ), Lock( 0 ), Show( 1 ) ),

  p2( 3, Min( 2.8 ), Max( 3.2 ), Lock( 0 ), Show( 1 ) )

  ),

  Simulator(

  1,

  Factors(

  p1 << Random( Weibull( 200, 3 ) ),

  p2 << Random( Weibull( 180, 3 ) )

  ),

  Responses( model << No Noise )

  )

  ),

  SendToReport(

  Dispatch(

  {"Prediction Profiler"},

  "2",

  ScaleBox,

  {Min( 2.8 ), Max( 3.2 ), Inc( 0.05 ), Minor Ticks( 1 )}

  ),

  Dispatch(

  {"Prediction Profiler"},

  "1",

  ScaleBox,

  {Min( 2.8 ), Max( 3.2 ), Inc( 0.05 ), Minor Ticks( 1 )}

  ),

  Dispatch(

  {"Prediction Profiler"},

  "Profiler",

  FrameBox,

  {Frame Size( 188, 114 )}

  ),

  Dispatch(

  {"Prediction Profiler"},

  "Profiler Simulator Distribution",

  FrameBox,

  {Frame Size( 178, 104 )}

  ),

  Dispatch(

  {"Prediction Profiler"},

  "Profiler",

  FrameBox( 3 ),

  {Frame Size( 188, 114 )}

  ),

  Dispatch(

  {"Prediction Profiler"},

  "Profiler Simulator Distribution",

  FrameBox( 2 ),

  {Frame Size( 178, 104 )}

  )

  )

);

2 REPLIES
ian_jmp

Staff

Joined:

Jun 23, 2011

FWIW (with JMP 12.2 on a Mac) and your code, I see the same thing.

But with JMP 13, I see:

12854_Screen Shot 2016-09-27 at 13.05.06.png

Jeff_Perkinson

Community Manager

Joined:

Jun 23, 2011

I agree with Ian@JMP​.

It appears to be a just a graphical bug that has been corrected in JMP 13.

-Jeff

-Jeff