topic Re: Using variables i JSL in Discussions

Using variables i JSL

Hauskov — Sat, 02 May 2020 11:04:07 GMT

I'm new to jsl but have a hard time understanding how it deals with variables. In the example below I define an LSL and alpha-value. It seems arbitrary to me, when jmp will use the defined variables and when it won't.

It has no problem using myLSL in Process Capability
It wont use myAlpha under Tolerance Interval. Instead, it will use the default value (but does not throw an error saying e.g. that the variable is unknown). If I put in a value directly, it works, but I want to be able to define a variable that I can then reference throughout the script.

Can someone help explain this to a novice jsl user? Or provide a relevant reference. Thank you!

myLSL = 2.1; myAlpha = 0.8;

// Distribution and Tolerance Interval
Current Data Table(dt);
Distribution(
	Continuous Distribution(
		Column("ColumnName"),
		Fit Distribution( Normal( Spec Limits( LSL( myLSL ) ) ) ),
		Process Capability( LSL( myLSL ), Target( . ), USL( . ) ),
		Tolerance Interval(
			Alpha( myAlpha ),
			Proportion( 0.90 ),
			Lower,
			Parametric Normal
		)
	),
);

Re: Using variables i JSL

Mark_Bailey — Sat, 02 May 2020 11:50:26 GMT

There remains inconsistencies in whether arguments can be variables or they must be literals. The Alpha() argument takes a literal argument. So you must substitute the value in the variable into the expression to make it literal.

Names Default to Here( 1 );

// example data set
dt = Open( "$SAMPLE_DATA/Big Class.jmp" );

myLSL = 50; myAlpha = 0.8;

// Distribution and Tolerance Interval
dist = dt << Distribution(
	Continuous Distribution(
		Column( :height ),
		Fit Normal( Process Capability( LSL( myLSL ), Target( . ), USL( . ) ) )
	)
);

Eval(
	Substitute(
		Expr(
			dist << Tolerance Interval(
				Alpha( aaa ),
				Proportion( 0.9 ),
				Lower,
				Parametric Normal
			)		),
		Expr( aaa ), myAlpha
	)
);

Re: Using variables i JSL

Craige_Hales — Sun, 03 May 2020 09:57:13 GMT

@Audrey_Shull

Re: Using variables i JSL

Audrey_Shull — Thu, 08 Apr 2021 15:08:07 GMT

Thank you for reporting this issue. JMP still has some inconsistencies regarding evaluation of JSL variables. However I can confirm that, in our next available release of JMP 16.1, the tolerance interval for Process capability will evaluate a variable for the alpha argument.