Chart in R not displaying data

问题

I have the following data frame:

        vector_builtin  vector_loop     vector_recursive
1            0.00        0.10             0.34
2            0.00        0.10             0.36
3            0.00        0.08             0.36
4            0.00        0.11             0.34
5            0.00        0.11             0.36

I want to display the three columns in a line chart.

I have imported ggplot2 into R and the chart is displaying without data or lines in it.

Code:

library(ggplot2)
indexes <- row.names(df.new)
ggplot(df.new, aes(x=vector_recursive, y=indexes))

Chart output

Output I want A chart showing the three series in a line chart.

回答1:

A very basic example using ggplot2 and df from OP can be:

df <- read.table(text = "time vector_builtin  vector_loop     vector_recursive
1            0.00        0.10             0.34
2            0.00        0.10             0.36
3            0.00        0.08             0.36
4            0.00        0.11             0.34
5            0.00        0.11             0.36", header = T, stringsAsFactors = F)

p <- ggplot() +
     geom_line(aes(time, vector_builtin, colour = "red"), data =  df) + 
     geom_line(aes(time, vector_loop, colour = "green"), data =  df) +
     geom_line(aes(time, vector_recursive, colour = "blue"), data =  df) +
     labs(x="Time(s)", y="Value") + # Labels for axis 
     scale_color_manual("Data Types", values=c(red="red",green="green",blue="blue"),
                 labels=c("vector_builtin", "vector_loop", "vector_recursive" ))

print(p)

回答2:

Make sure that you have your data in a format that ggplot2 understands. In your code, geom_line is expecting you to provide which columns in your data should correspond to which question. Below I have recreated your data, in the future, consider using dput to provide the data to others, which will help troubleshoot your specific issue.

df=data.frame(vector_builtin=c(0.00,0.00,0.00,0.00,0.00),
           vector_loop=c(0.10,0.10,0.08,0.11,0.11),
           vector_recursive=c(0.34,0.36,0.36,0.34,0.36))

However, you don't specify what your x axis is, so we will create a new variable that holds that information, for example:

df$x=1:5

Now, I would recommend reshaping the data into long format, which is preferred by ggplot2. You could also use the other answer here and specify each without that problem, but reshape2's melt function could be used.

library(reshape2)
df.m = melt(df, id.vars="x")

Now when you correctly identify the names of the columns to plot, ggplot2 will plot the data correctly:

ggplot() + geom_line(aes(color=variable, x=x, y=value), data=df.m)

来源：https://stackoverflow.com/questions/48491246/chart-in-r-not-displaying-data

标签

charts