topic Re: Slope -Liner regression in Discussions

Slope -Liner regression

pankajsync — Sat, 10 Jun 2023 23:49:55 GMT

I would like to calculate the slope in linear regression fashion. It should be a column formula. And the slope value should be single value (Averaged) for the below table.

Group	Subgroup	Log[V]	Log[T3]	Slope
1	a	1.609438	7.953736	Calculate slope for 1, a
1	a	1.648659	6.777461
1	a	1.686399	5.296072
1	b	1.609438	8.953736	Calculate slope for 1, b
1	b	1.648659	7.777461
1	b	1.686399	6.296072
2	a	1.609438	17.95374	Calculate slope for 2, a
2	a	1.648659	16.77746
2	a	1.686399	15.29607
2	b	1.609438	38.95374	Calculate slope for 2, b
2	b	1.648659	37.77746
2	b	1.686399	36.29607

Re: Slope -Liner regression

Mark_Bailey — Fri, 17 Jun 2022 19:08:46 GMT

See the Linear Regression() function in the Help > Scripting Index for your formula. You might need to use a script, though. Subscripting the rows into groups of three might be difficult in a formula.

Re: Slope -Liner regression

pankajsync — Fri, 17 Jun 2022 22:10:04 GMT

Forgot to mention. Slope should be Log[T3]/Log[V]

Re: Slope -Liner regression

pankajsync — Fri, 17 Jun 2022 22:11:41 GMT

yes aware of this function. But want to want different slopes for different groups.

Combination of Group and SUBGROUP should have one unique value of slope.

Re: Slope -Liner regression

jthi — Sat, 18 Jun 2022 15:37:11 GMT

Create new grouping column which is combination of Group and Subgroup to make it a bit easier. Then write a formula which will get values for specific group for LogV and LogT3 (many options for this). After this you can use Linear Regression function to get the estimates for slope. If you really want to see only one value for each group, then add check that if you are on first row of the group -> perform calculations, otherwise return missing.