[R] individual intercept and slope

[Rosario Garcia Gil]

Hello

I would like to extract the estimates for the intercept and slope by individual for growth from a lm fit.
Any advice?

Individual Time point      Height
1			1           10
1			2		11
1			3		23
1			4		15
1			5		21
1			6		23
2			1		24
2			2		12
2			3		9
2			4		10
2			5		11
2			6		10
...

Thanks