R - visualising data over time - r

Question

I'm trying to plot a dataset over time (timeframe of ms/s). I need to show the order of events, the type of event and the duration of each event + the time between events. The dataset consists of a start time, end time and category.
I got close with this code someone used to answer a similar question back in '11 but found that I couldn't get it to colour the events according to the category, and I don't understand what the code is doing well enough to fix the issue.
zucchini <- function(st, en, mingap=1)
{
i <- order(st, en-st);
st <- st[i];
en <- en[i];
last <- r <- 1
while( sum( ok <- (st > (en[last] + mingap)) ) > 0 )
{
last <- which(ok)[1];
r <- append(r, last);
}
if( length(r) == length(st) )
return( list(c = list(st[r], en[r]), n = 1 ));
ne <- zucchini( st[-r], en[-r]);
return(list( c = c(list(st[r], en[r]), ne$c), n = ne$n+1));
}
{
zu <- zucchini(st, en, mingap = 1);
plot.new();
plot.window( xlim=c(min(st), max(en)), ylim = c(0, zu$n+1));
box(); axis(1);
for(i in seq(1, 2*zu$n, 2))
{
x1 <- zu$c[[i]];
x2 <- zu$c[[i+1]];
for(j in 1:length(x1))
rect( x1[j], (i+1)/2, x2[j], (i+1)/2+0.5,col=data$Type, border="black",
);
legend('bottomright', legend = levels(data$Type), col = 1:10, cex = 0.8, pch = 1)}
}
st <- data$Time
en <- data$End
coliflore(st,en)
current code outputs this As best as I can tell it is assigning all boxes the same colour, that of the category of the first data point.
Does anyone know either: how to get this code to assign colours to the boxes based on a category, or how to accomplish this kind of plotting another way?

Answer 1

Its a little hard to for me to see whats going on without a toy dataset for your example. For maximum control over coloring in plots I like to add a color column to the dataframe or create a vector to store color values for use in plotting instead of using the factor levels to generate colors (eg data$Type). For instance if I want factors 1:3 to be red, green, and blue:
# create data frame with X,Y coordinates and 3 factor levels
toy_data<- data.frame (X= 1:9, Y=9:1, Factor = rep(1:3, times=3))
# create a vector of colors to use for plotting
# color function
colFxn<-function(val){
cw_df<-data.frame(value=1:3, color = c("red", "green", "blue"))
return(cw_df[cw_df$value %in% val,]$color)
}
col_vec<-sapply (toy_data$Factor, colFxn)
#plot
plot(toy_data$X, toy_data$Y, col=col_vec)
I prefer this option because of the control I have over my colors. This can also be expanded to transparent colors by changing the alpha value using the RGB function, or through using a color pallet available through many packages.