R Line | R Line Graphs - r - learn r - r programming
- A line chart is a graph that connects a series of points by drawing line segments between them.
- These points are ordered in one of their coordinate (usually the x-coordinate) value.
- Line charts are usually used in identifying the trends in data.
Syntax
- The basic syntax to create a line chart in R is −
plot(v,type,col,xlab,ylab)
Following is the description of the parameters used −
- v is a vector containing the numeric values.
- type takes the value "p" to draw only the points, "l" to draw only the lines and "o" to draw both points and lines.
- xlab is the label for x axis.
- ylab is the label for y axis.
- main is the Title of the chart.
- col is used to give colors to both the points and lines.
Example
- A simple line chart is created using the input vector and the type parameter as "O".
- The below script will create and save a line chart in the current R working directory.
Sample Code
# Create the data for the chart.
v <- c(7,12,28,3,41)
# Give the chart file a name.
png(file = "line_chart.jpg")
# Plot the bar chart.
plot(v,type = "o")
# Save the file.
dev.off()
Output
Line Chart, Color and Labels
- The features of the line chart can be expanded by using additional parameters.
- We add color to the points and lines, give a title to the chart and add labels to the axes.
Sample Code
# Create the data for the chart.
v <- c(7,12,28,3,41)
# Give the chart file a name.
png(file = "line_chart_label_colored.jpg")
# Plot the bar chart.
plot(v,type = "o", col = "red", xlab = "Month", ylab = "Rain fall",
main = "Rain fall chart")
# Save the file.
dev.off()
Output
Multiple Lines in a Line Chart
- More than one line can be drawn on the same chart by using the lines() function.
- After the first line is plotted, the lines() function can use an additional vector as input to draw the second line in the chart,
Sample Code
# Create the data for the chart.
v <- c(7,12,28,3,41)
t <- c(14,7,6,19,3)
# Give the chart file a name.
png(file = "line_chart_2_lines.jpg")
# Plot the bar chart.
plot(v,type = "o",col = "red", xlab = "Month", ylab = "Rain fall",
main = "Rain fall chart")
lines(t, type = "o", col = "blue")
# Save the file.
dev.off()
Output
