Re: [R] Interpreting model matrix columns when using contr.sum

2009-01-25 Thread Douglas Bates
On Fri, Jan 23, 2009 at 4:58 PM, Gang Chen gangch...@gmail.com wrote: With the following example using contr.sum for both factors, dd - data.frame(a = gl(3,4), b = gl(4,1,12)) # balanced 2-way model.matrix(~ a * b, dd, contrasts = list(a=contr.sum, b=contr.sum)) (Intercept) a1 a2 b1 b2

Re: [R] Interpreting model matrix columns when using contr.sum

2009-01-25 Thread John Fox
-help-boun...@r-project.org] On Behalf Of Douglas Bates Sent: January-25-09 10:49 AM To: Gang Chen Cc: R-help Subject: Re: [R] Interpreting model matrix columns when using contr.sum On Fri, Jan 23, 2009 at 4:58 PM, Gang Chen gangch...@gmail.com wrote: With the following example using

Re: [R] Interpreting model matrix columns when using contr.sum

2009-01-25 Thread Gang Chen
...@r-project.org] On Behalf Of Douglas Bates Sent: January-25-09 10:49 AM To: Gang Chen Cc: R-help Subject: Re: [R] Interpreting model matrix columns when using contr.sum On Fri, Jan 23, 2009 at 4:58 PM, Gang Chen gangch...@gmail.com wrote: With the following example using contr.sum

[R] Interpreting model matrix columns when using contr.sum

2009-01-23 Thread Gang Chen
With the following example using contr.sum for both factors, dd - data.frame(a = gl(3,4), b = gl(4,1,12)) # balanced 2-way model.matrix(~ a * b, dd, contrasts = list(a=contr.sum, b=contr.sum)) (Intercept) a1 a2 b1 b2 b3 a1:b1 a2:b1 a1:b2 a2:b2 a1:b3 a2:b3 11 1 0 1 0 0