Question

I would like to visualize the time frame data of my five projects given below. Currently I am using OpenOffice draw application and manually producing the graph shown below. But I am not satisfied. Could you help me to solve the following. Thank you.

1. How can I produce somewhat similar graphs using R (or excel) with better precision in terms of days? 
2. Is there a way for better visualization of the data? If so, please let me know how to produce that using R or Excel. 

Project     Time
-------    ------ 
A   Feb 15 – March 1
B   March 15 – June 15
C   Feb 1 – March 15
D   April 10 – May 15
E   March 1 – June 30

Answer 1

ggplot2 provides a (reasonably) straightforward way to construct a plot.

First you need to get your data into R. You want your starting and ending dates to be some kind of Date format in R (I have used Date)

library(ggplot2)
library(scales) # for date formatting with ggplot2

DT <- data.frame(Project = LETTERS[1:5], 
  start = as.Date(ISOdate(2012, c(2,3,2,4,3), c(15,15,1,10) )),
  end = as.Date(ISOdate(2012, c(3,5,3,5,6), c(1,15,15,15,30))))
# it is useful to have a numeric version of the Project column (
DT$ProjectN <- as.numeric(DT$Project)

You will also want to calculate where to put the text, I will use `ddply1 from the plyr package

library(plyr)
# find the midpoint date  for each project
DTa <- ddply(DT, .(ProjectN, Project), summarize, mid = mean(c(start,end)))

You want to create

• rectangles for each project, hence you can use geom_rect
• text labels for each midpoint

Here is an example how to build the plot

ggplot(DT) + 
   geom_rect(aes(colour = Project,ymin = ProjectN - 0.45, 
                ymax = ProjectN + 0.45,  xmin = start, xmax = end)), fill = NA) + 
  scale_colour_hue(guide = 'none') +  # this removes the legend
 geom_text(data = DTa, aes(label = Project, y = ProjectN, x = mid,colour = Project), inherit.aes= FALSE) + # now some prettying up to remove text / axis ticks
  theme(panel.background = element_blank(), 
        axis.ticks.y = element_blank(), axis.text.y = element_blank()) + # and add date labels
  scale_x_date(labels = date_format('%b %d'), 
  breaks = sort(unique(c(DT$start,DT$end))))+ # remove axis labels
  labs(y = NULL, x = NULL)