Appologies in advance for multiple things scrunched into 1 post.
Need help detemerming what to do if no distribution (continuous ) fits the data (attached).
Most of the variables are not normal. Thus, running PROC Univariate to see what structures best fit my continuous data before I run GLIMMIX. Lots of variables, but for now, I'll focus on suppDMIkg.
Study design (lamb feeding trial): Effects of using 2 different feed ingredients (juniper and urea) in supplements fed to ewe lambs on the following dependent variables: intake (supplement, hay, and total), growth (BW gain, efficiency, etc.), and blood serum (e.g., glucose).
- Animal = exp. unit; each lamb has own unique ID
- All lambs fed hay. Each lamb also fed respective treatment: 1 of 8 different feeds in a 4×2 factorial: 4 juniper levels (15, 30, 45, or 60%) and 2 urea levels (1 or 3%).Feed Intake and Growth evaluated on d 0, 5, 12, 19, 26, 33, and 40.
- Focusing right now on supplement intake (SAS name = suppDMIkg)
Objectives:
- Does increasing level of juniper in the supplement result in linear, quadratic, or cubic trends in intake, growth, or blood serum componenets?
- Does the response (increasing juniper) change over days on trial?
- Does the response (increasing juniper) change due to level of urea?
I struggled with the contrast statements for suppDMIkg, but I think I got it figured out. When I used "e" it gave me coef. that didn't work (didn't equal 0), thus I calculated them myself.
QUESTION: Is the following method to construct the coeff. correct?
QUESTION: How is a 3-way interaction handled? e.g., JUNIPER x UREA x day
I ran PROC IML for juniper and then for day. I then cross multiplied and got my coefficients (final result = 0) for linear, quad, and cubic.
CONTRAST 'LINEAR JUNIPER' JUN -3 -1 1 3/e;
CONTRAST 'QUADRADIC JUNIPER' JUN 1 -1 -1 1/e;
CONTRAST 'CUBIC JUNIPER' JUN -1 3 -3 1/e;
CONTRAST 'LINEAR JUN*day' JUN*day
1.792842 1.075707 0.358569 -0.3585687 -1.0757058 -1.7928429
0.597614 0.358569 0.119523 -0.1195229 -0.3585686 -0.5976143
-0.597614 -0.358569 -0.119523 0.1195229 0.3585686 0.5976143
-1.792842 -1.075707 -0.358569 0.3585687 1.0757058 1.7928429/e;
CONTRAST 'QUADRADIC JUN*day' JUN*day
0.5455447 -0.109109 -0.436436 -0.436436 -0.109109 0.5455447
-0.5455447 0.109109 0.436436 0.436436 0.109109 -0.5455447
-0.5455447 0.109109 0.436436 0.436436 0.109109 -0.5455447
0.5455447 -0.109109 -0.436436 -0.436436 -0.109109 0.5455447/e;
CONTRAST 'CUBIC JUN*day' JUN*day
0.372678 -0.5217492 -0.2981424 0.298142 0.521749 -0.372678
-1.118034 1.5652476 0.8944272 -0.894426 -1.565247 1.118034
1.118034 -1.5652476 -0.8944272 0.894426 1.565247 -1.118034
-0.372678 0.5217492 0.2981424 -0.298142 -0.521749 0.372678/e;
| |
DAY |
|
|
|
|
|
|
| linear |
5 |
12 |
19 |
26 |
33 |
40 |
|
| juniper |
-0.597614 |
-0.358569 |
-0.119523 |
0.1195229 |
0.3585686 |
0.5976143 |
|
| -3 |
1.792842 |
1.075707 |
0.358569 |
-0.3585687 |
-1.0757058 |
-1.7928429 |
-1.7292429 |
| -1 |
0.597614 |
0.358569 |
0.119523 |
-0.1195229 |
-0.3585686 |
-0.5976143 |
-0.5764143 |
| 1 |
-0.597614 |
-0.358569 |
-0.119523 |
0.1195229 |
0.3585686 |
0.5976143 |
0.5764143 |
| 3 |
-1.792842 |
-1.075707 |
-0.358569 |
0.3585687 |
1.0757058 |
1.7928429 |
1.7292429 |
| |
0 |
0 |
0 |
0 |
0 |
0 |
0.00000000 |
I'm ultimately trying to run PROC GLIMMIX, using the correct distribution.
QUESTION: If an interaction is not significant in the model (e.g., JUNxDAY), but contrast statement shows a linear JUNxDAY interaction, can one still discuss that linear interaction or is it protected by the model P-value (must be < 0.05)?
DATA LAMB; SET grow;
oneMinusSuppDMIkg = 1-suppDMIkg;
PROC SORT; BY DAY ID JUN UREA; RUN;
PROC GLIMMIX;
CLASS ID JUN UREA DAY;
MODEL oneMinusSuppDMIkg = DAY JUN UREA DAY*JUN DAY*UREA JUN*UREA/dist=LOGNORMAL ddfm=kr solution;
*/original model, the 3-way interaction was not sign., thus I dropped it/*
Random day /residual subject = ID type =UN; */what is the difference between this and "Random _residual_/subject ID(DAY) ..."/*
CONTRAST 'LINEAR JUNIPER' JUN -3 -1 1 3/e;
CONTRAST 'QUADRADIC JUNIPER' JUN 1 -1 -1 1/e;
CONTRAST 'CUBIC JUNIPER' JUN -1 3 -3 1/e;
CONTRAST 'LINEAR JUN*day' JUN*day
1.792842 1.075707 0.358569 -0.3585687 -1.0757058 -1.7928429
0.597614 0.358569 0.119523 -0.1195229 -0.3585686 -0.5976143
-0.597614 -0.358569 -0.119523 0.1195229 0.3585686 0.5976143
-1.792842 -1.075707 -0.358569 0.3585687 1.0757058 1.7928429/e;
CONTRAST 'QUADRADIC JUN*day' JUN*day
0.5455447 -0.109109 -0.436436 -0.436436 -0.109109 0.5455447
-0.5455447 0.109109 0.436436 0.436436 0.109109 -0.5455447
-0.5455447 0.109109 0.436436 0.436436 0.109109 -0.5455447
0.5455447 -0.109109 -0.436436 -0.436436 -0.109109 0.5455447/e;
CONTRAST 'CUBIC JUN*day' JUN*day
0.372678 -0.5217492 -0.2981424 0.298142 0.521749 -0.372678
-1.118034 1.5652476 0.8944272 -0.894426 -1.565247 1.118034
1.118034 -1.5652476 -0.8944272 0.894426 1.565247 -1.118034
-0.372678 0.5217492 0.2981424 -0.298142 -0.521749 0.372678/e;
LSMEANS /DIFF ADJUST=simulate (REPORT SEED = 121211) CL LINES ILINK;
LSmeans JUN UREA DAY/DIFF adjust=SIMULATE (REPORT SEED = 121211) CL LINES adjdfe=row ILINK;
RUN; Quit;
