ggplot bar chart for time series

ggplot2, r

Solution

Hope this is what you are looking for:

`ggplot2` requires data in a long format.

require(reshape2)
m_molten <- melt(m, "dates.f")

Plotting itself is done by

ggplot(m_molten, aes(x=dates.f, y=value, fill=variable)) + 
  geom_bar(stat="identity")

You can add `position="dodge"` to `geom_bar` if you want then side by side.

EDIT

If you want yearly breaks only: convert `m_molten$dates.f` to date.

require(scales)
m_molten$dates.f <- as.Date(m_molten$dates.f)

ggplot(m_molten, aes(x=dates.f, y=value, fill=variable)) + 
  geom_bar(stat="identity") + 
  scale_x_date(labels = date_format("%y"), breaks = date_breaks("year"))

P.S.: See http://vita.had.co.nz/papers/tidy-data.pdf for Hadley's philosophy of tidy data.

Problem

I'm reading the book by Hadley Wickham about ggplot, but I have trouble to plot certain weights over time in a bar chart. Here is sample data: ``` dates <- c("20040101","20050101","20060101") dates.f <- strptime(dates,format="%Y%m%d") m <- rbind(c(0.2,0.5,0.15,0.1,0.05),c(0.5,0.1,0.1,0.2,0.1),c(0.2,0.2,0.2,0.2,0.2)) m <- cbind(dates.f,as.data.frame(m)) ``` This data.frame has in the first column the dates and each row the corresponding weights. I would like to plot the weights for each year in a bar chart using the "fill" argument. I'm able to plot the weights as bars using: ``` p <- ggplot(m,aes(dates.f)) p+geom_bar() ``` However, this is not exactly what I want. I would like to see in each bar the contribution of each weight. Moreover, I don't understand why I have the strange format on the x-axis, i.e. why there is "2004-07" and "2005-07" displayed. Thanks for the help

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