R-bios6643-L09sas-COHO-Elizabeth.Rmd

---
title: "BIOS6643. L8 Covariance Structures $R_i$"
cheauthor: "EJC"
-- date: "" 
header-includes:
   - \usepackage{amsmath}
   - \usepackage{float}
output: pdf_document
---

\newcommand{\bi}{\begin{itemize}}
\newcommand{\ei}{\end{itemize}}
\newcommand{\itt}{\item}


```{r setup, include=FALSE, echo=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

<!-- -->


```{r installp, echo = FALSE, eval=T, include=F}
library(dplyr)
library(tidyverse)
library(ggplot2)
library(nlme)
## library(SASmarkdown)

```

```{r include=FALSE}
# set up the options so that knit knows where you SAS executable is
# set the line size to be easily readable on letter size paper, portrait
# and set the knitr options using opts_chunk$set().
sasopts <- "-nosplash -linesize 75"
saspath <- "C:/Program Files/SASHome/SASFoundation/9.4/sas.exe"
## those two parts should have been universal 
## just copy and paste into your Rmarkdown files
knitr::opts_chunk$set(engine = "sas", 
                      engine.path = saspath, 
                      engine.opts = sasopts, 
                      comment = NA)

```




```{r engine="sas", engine.path="C:/Program Files/SASHome/SASFoundation/9.4/sas.exe", engine.opts="-nosplash -linesize 75", collectcode=TRUE}


proc import DATAFILE='C:\Users\juarezce\OneDrive - The University of Colorado Denver\BIOS6643\BIOS6643_Notes\data\dental.csv'
  replace out=dental dbms=csv; run;

 proc print data=dental(obs=2);run;

  
  title '(a) DIAGONAL WITHIN-CHILD COVARIANCE MATRIX R_i';
title2 'WITH CONSTANT VARIANCE SAME FOR EACH GENDER';
title3 'SAME D MATRIX FOR BOTH GENDERS';
proc mixed method=ml data=dent1;
  class gender id;
  model distance = gender gender*age / noint solution;
  random intercept age / type=un subject=child g gcorr v vcorr;

* comparison of mean slopes and whether mean intercepts and slopes;
* coincide for each gender;

  estimate 'diff in mean slope' gender 0 0 gender*age 1 -1;
  contrast 'overall gender diff' gender 1 -1, gender*age 1 -1 /chisq;
run;
  /* */
  
```