prest <- function(f1)
{
# Written by Daniel E. Weeks (weeks@pitt.edu)
#
# Purpose: To draw out the relationship triangles for a prest_out2 file.
# Title will be the p0, p1, and p2 sharing
# Subtitle will be the ped, per1, per2, relationship, number of markers, and EIBD p-value.
# Input:
#   a 'prest_out2' output file generated by the PREST program.
# Usage:
# > source("prest.r")
# > postscript(paper="letter",horizontal=F)
# > prest("prest_out2")
# > dev.off()
#
a <- read.table(f1,header=F);
alength <- dim(a)[2];
if (alength == 16) {
names(a) <- 
c("ped","per1","per2","rel","num","eibd","p0","p1","p2","pval1","pval2","pval3","pv1","pv2","pv3","pv4");
} else {
names(a) <- 
c("ped","per1","per2","rel","num","eibd","p0","p1","p2","pval1","pval2","pval3");
}
attach(a);
# This sets up a 5 rows x 3 columns grid of graphs per page.
par(mfcol=c(5,3));
for (i in 1:length(ped))
tri(p0[i],p1[i],ped[i],per1[i],per2[i],rel[i],num[i],pval1[i],p2[i]);
}

tri <- function(z0,z1,ped,per1,per2,rel,num,pval1,p2)
# R code for drawing the relationship triange of
# Elizabeth Thompson
{
z2 <- 1.0 - z0 - z1;
x <- c(0.0000,0.5774,1.1547,0.0000)
y <- c(0.0,1.0,0.0,0.0)
plot(x,y,type="l",xlab="",ylab="")
x2 <- (z0/1.7321 + z1/0.8660)
y2 <- z0
points(x2,y2)
t <- paste(z0,z1,p2);
s <- paste(ped,per1,per2,rel,num,pval1);
# Place a cross at the full sib position.
title(t,sub=s);
s1 <- 0.7217007;
s2 <- 0.25;
points(s1,s2,pch=3);
# Place a cross at the half sib position.
s1 <- 0.8660341;
s2 <- 0.5;
points(s1,s2,pch=3);
text(s1+0.12,s2,"HS");
# text(0.5873339,1.015,"U");
list(z0 = z0, z1 = z1, z2 = 1.0 - z0 -z1, x = x2, y = y2);
}