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Adding spec limits to a control chart

kellys

Community Trekker

Joined:

Jul 8, 2013

Hello,

I am writing a script to add specification limits to a control chart.  The script I am using to do this is below.  This is perfect when I have a LSL, avg and USL but if I just have an LSL and USL, for example, JMP calculates an average and adds it to the control chart.  Is there a way to prevent this auto-calculation in cases when I don’t specify all 3 spec limits?

dtlimits = Open();

lm = dtlimits << get as matrix;

Close( dtlimits, nosave );

FinalDataSet << Control Chart(

      Sample Label( :DOM ),

      KSigma( 3 ),

      Chart Col(

            :VALUE,

            Levey Jennings(   LCL(lm[1]),

                              AVG(lm[2]),

                              UCL(lm[3]),Test 2( 1 ), Test 3( 1 ), Test Beyond Limits( 1 ) )

      )

)

2 REPLIES
Jeff_Perkinson

Community Manager

Joined:

Jun 23, 2011

Hi Kelly,

There's an option in the hotspot menu for Levey Jennings charts to turn off the center line.

3890_JMPScreenSnapz004.png

When you turn this option off and then save the script to the script window you can find the JSL syntax for this option is Show Center Line (0).

So, this script will result in a Levey Jennings chart without the center line:

Control Chart(

   Sample Label( :DAY ),

   KSigma( 3 ),

   Chart Col(

      :DIAMETER,

      Levey Jennings(

         LCL( 4.25 ),

         UCL( 5.75 ),

         Show Center Line( 0 )

      )

   )

);

-Jeff
kellys

Community Trekker

Joined:

Jul 8, 2013

Thanks!