topic Re: how to calculate standard deviation across multiple columns? in Discussions

how to calculate standard deviation across multiple columns?

emmablue — Thu, 27 Jun 2024 18:24:47 GMT

Is it possible to use JMP to calculate standard deviation across multiple columns? I could only figure out how to do the calculation in the same column.

first	second	third	CV
2.450712	2.441128	2.430674
1.267139	1.258429	1.260132
2053.459	2062.341	2067.839
1.752283	1.761982	1.763598
1.108177	1.113778	1.115453
1.232238	1.225236	1.232238
2.471146	2.465444	2.456794

Re: how to calculate standard deviation across multiple columns?

Jordan_Hiller — Thu, 27 Jun 2024 18:46:54 GMT

You're looking for the "Std Dev" function.

https://www.jmp.com/support/help/en/18.0/#page/jmp/statistical-functions.shtml#

See attached data table as well.

Re: how to calculate standard deviation across multiple columns?

jthi — Thu, 27 Jun 2024 18:47:54 GMT

Do you mean by row? You can for example use Std Dev function and list the columns

Std Dev(:first, :second, third)

Re: how to calculate standard deviation across multiple columns?

txnelson — Thu, 27 Jun 2024 18:58:23 GMT

If you are attempting to calculate the Coefficient of Variation for each row, it would be:

names default to here(1);
dt=
New Table( "example",
	Add Rows( 7 ),
	New Column( "first",
		Numeric,
		Set Values(
			[2.4507119999999998, 1.267139, 2053.4589999999998, 1.752283, 1.108177,
			1.2322379999999999, 2.4711460000000001]
		)
	),
	New Column( "second",
		Numeric,
		Set Values(
			[2.441128, 1.258429, 2062.3409999999999, 1.7619819999999999,
			1.1137779999999999, 1.225236, 2.4654440000000002]
		)
	),
	New Column( "third",
		Numeric,
		Set Values(
			[2.4306739999999998, 1.260132, 2067.8389999999999, 1.763598, 1.115453,
			1.2322379999999999, 2.4567939999999999]
		)
	)
);

dt << new column("CV", formula( stddev(:first,:second,:third)/mean(:first,:second,:third)));

If you want to calculate the STD for the complete data table matrix it would be

names default to here(1);
dt=
New Table( "example",
	Add Rows( 7 ),
	New Column( "first",
		Numeric,
		Set Values(
			[2.4507119999999998, 1.267139, 2053.4589999999998, 1.752283, 1.108177,
			1.2322379999999999, 2.4711460000000001]
		)
	),
	New Column( "second",
		Numeric,
		Set Values(
			[2.441128, 1.258429, 2062.3409999999999, 1.7619819999999999,
			1.1137779999999999, 1.225236, 2.4654440000000002]
		)
	),
	New Column( "third",
		Numeric,
		Set Values(
			[2.4306739999999998, 1.260132, 2067.8389999999999, 1.763598, 1.115453,
			1.2322379999999999, 2.4567939999999999]
		)
	)
);

totalSTD = stddev(dt[0,0]);
show(totalSTD);
)