polygon() function in R Language is used to plot a polygon between specified points in an existing plot.
Syntax: polygon(x_coordinates, y_coordinates) Parameters : x_coordinates, y_coordinates: x, y coordinates of plot to draw polygon Returns: a polygon in a given plot
Example 1: Draw a Square Polygon in an R Plot
# R program to draw a polygon # Draw an empty plot plot (2, 2, col = "white", xlab = "X", ylab = "Y")
# Draw a polygon polygon (x = c (2.7, 2.3, 2.2, 2.8), # X-Coordinates of polygon
y = c (2.6, 2.8, 2.4, 2), # Y-Coordinates of polygon
col = "darkgreen")
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Output:
# R program to draw a polygon # Draw empty plot plot (2, 2, col = "white", xlab = "X", ylab = "Y")
# Draw a polygon polygon (x = c (2.7, 2.3, 2.2, 2.8), # X-Coordinates of polygon
y = c (2.6, 2.8, 2.4, 2), # Y-Coordinates of polygon
col = "darkgreen", # Color of polygon
border = "red", # Color of polygon border
lwd = 8) # Thickness of border
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Output:
Here, border specifies the border color and lwd specifies the border thickness.
Example 3: Draw frequency polygon
# R program to draw a polygon # X values for frequency polygon x1 <- 1:10 # Y values for frequency polygon y1 <- c (2, 4, 7, 4, 5, 8, 6, 6, 1, 2)
# Plot frequency polygon plot (x1, y1,
type = "l", # Set line type to line
lwd = 4) # Thickness of line
# X-Y-Coordinates of polygon polygon ( c (1, x1, 10), c (0, y1, 0),
col = "darkgreen") # Color of polygon
# Add squares to frequency polygon points (x1, y1,
cex = 1, # Size of squares
pch = 12)
segments (x1, 0, x1, y1)
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Output:
# R program to draw a polygon # Set seed for reproducibility set.seed (15000)
# Sample size N <- 1000 # Draw random poisson distribution x1 <- rpois (N, 2)
plot ( density (x1), # Draw density plot
main = "", # No main title
xlab = "x1") # Set name of x-axis to x2
# X-Coordinates of polygon polygon ( c ( min ( density (x1)$x), density (x1)$x),
c (0, density (x1)$y), # Y-Coordinates of polygon
col = "darkgreen") # Color of polygon
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Output:
Here, above example is used to make Probability density function.
Example :
# Define the x and y coordinates of the polygon vertices x <- c (1, 3, 4, 2)
y <- c (1, 2, 4, 3)
# Plot the polygon plot (x, y, type = "n" ) # type = "n" to create an empty plot
polygon (x, y, col = "blue" )
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output :