<html><head><style>body{font-family:Helvetica,Arial;font-size:13px}</style></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;">This is the mailing list for R’s data.table package. Please post on r-help mailing list.</div> <br> <div id="bloop_sign_1463914773658780160" class="bloop_sign"><div style="font-family:helvetica,arial;font-size:13px">-- <br>Arun</div></div> <br><p class="airmail_on">On 22 May 2016 at 10:44:29, CRoa (<a href="mailto:carlosalvarezroa@hotmail.com">carlosalvarezroa@hotmail.com</a>) wrote:</p> <blockquote type="cite" class="clean_bq"><span><div><div></div><div>Hi all,
<br>I was wondering if someone could help me designing a contrast matrix when
<br>you have a continuous variable (Days).
<br>
<br>My model looks like this:
<br>
<br>model<-lme(Y~A*B*Days, data=data_over_time)
<br>
<br>The factor A has two levels (A1 and A2) and factor B has three levels (B1,
<br>B2, and B3). I measured the response variable Y every two or three days over
<br>70 days (Days).
<br>I need to look at only a few comparisons over the 70 days such us:
<br> A1 and B1 vs A2 and B1,
<br> A2 and B2 vs A2 and B1,
<br> A1 and B2 vs A2 and B2
<br>I could use the function contrast from the package contrast to design the
<br>matrix with the three comparisons mentioned above for specific days at a
<br>time. However, I need to run the comparison over the 70 days not at
<br>individual time points.
<br>
<br>I was wondering if someone could help me designing this contrast matrix.
<br>
<br>Any help would be much appreciated
<br>Cheers
<br>
<br>
<br>
<br>--
<br>View this message in context: http://r.789695.n4.nabble.com/Contrast-matrix-with-a-continuous-variable-tp4720966.html
<br>Sent from the datatable-help mailing list archive at Nabble.com.
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