The plot() function in R is **“used to create a plot”**. It has many options and arguments to control many things, such as the **plot type, labels, titles,** and **colors**. For example, **plot(x, y)** creates a scatter plot of x and y numeric vectors.

**Syntax**

`plot(x, y, type, main, xlab, ylab, pch, col, las, bty, bg, cex, …)`

**Parameters**

The **x **is the coordinates of points in the plot.

The **y**** **is the coordinates of points in the plot.

**main:** It is an overall title for the plot.

**xlab:** It is a label for the x-axis.

**ylab:** It is the label for the y-axis.

**pch:** It is the shape of points.

**col:** It is the foreground color of symbols as well as lines.

**las:** It is the axes label style.

**bty:** It is the type of box around the plot area.

**bg:** It is the background color of symbols (only 21 through 25).

**cex:** It is an amount of scaling plotting text and symbols.

**… **They are the arguments to be passed to methods.

- “
**p**” for points plot,

- “
**l**” for a line plot,

- “
**b**” for both plots,

- “
**c**” for the part of the line alone of “b”,

- “
**o**” for both**“overplotted”**,

- “
**h**” for ‘histogram’ like (or “**high-density**“) vertical lines.

- “
**s**” for stair steps,

- “
**S**” for other steps. See ‘Details’ below,

- “
**n**” for no plotting.

**Example 1: Simple plot() function implementation**

Let’s use the equation **y = x^3**. This means we will define two vectors, x and y, and y is the cube of x.

```
x <- c(1, 2, 3, 4, 5)
y <- c(1, 8, 27, 64, 125)
```

Let’s plot the y = x^3 values on the line plot. To create a line plot, pass the parameter type = “l” inside the plot function.

```
x <- c(1, 2, 3, 4, 5)
y <- c(1, 8, 27, 64, 125)
plot(x, y, type = "l")
```

**Output**

And we get the line chart of the **y = x^3** function.

If we don’t pass the **type = “l”** in the argument, it will return the points plot. By default, the plot() function returns a **point plot.**

**Example 2: Plot the cos() function in R**

To calculate the cosine value in R, use the cos() function. Next, we plot the sine function using the **pi** **constant** from the range **-pi** to **pi**.

```
x <- seq(-pi, pi, 0.1)
plot(x, cos(x))
```

**Output**

**Example 3: Adding titles and labeling axes**

To add a title to our plot, use the **main **parameter and pass the name of your choice.

To label the x and y-axis, use the **xlab** and **ylab** arguments.

```
x <- seq(-pi, pi, 0.1)
plot(x, cos(x), main = "Cos Function", ylab = "cos(x)")
```

**Output**

**Example 4: Changing the symbols and colors of a plot in R**

We can see above that the plot is of circular points and is black in color. This is the default color.

Let’s change the symbol using the **pch **and** col **parameters for choosing the color.

```
x <- seq(-pi, pi, 0.1)
plot(x, cos(x), pch = c(4, 5, 6), col = c("red", "blue", "violet", "green"))
```

**Output**

**Example 5: Plot multiple graphs into a single image in R**

To combine multiple graphs into a single image, use the **par()** function.

Let’s combine two graphs. 1st is a line chart, and 2nd is a point chart with different symbols and colors.

```
par(mfrow = c(1, 2))
x <- seq(-pi, pi, 0.1)
plot(x, cos(x), type="l")
plot(x, cos(x), pch = c(4, 5, 6), col = c("red", "blue", "violet", "green"))
```

**Output**

You can also add more graphs using the par() function. For example, let’s add six graphs in one image in R.

```
par(mfrow = c(2, 3))
x <- seq(-pi, pi, 0.1)
plot(x, cos(x), type = "l")
plot(x, cos(x), pch = c(4, 5, 6), col = c("red", "blue", "violet", "green"))
plot(x, x ^ 3, col = "red", type = "l")
m <- 0.8
c <- 2
plot(x, m * x + c, col = "green", type = "o", lwd = 2, lty = 1)
plot(x, log(x), col = "violet", type = "s")
plot(x, exp(x), col = "red", type = "b")
```

**Output**

**Example 6: Overlaying Plots Using legend() function in R**

Sometimes, we need to overlay the plots to compare the results. To overlay the plot, use the **lines()** and **points()** methods to add lines and points to the existing plot.

```
x <- seq(-pi, pi, 0.1)
plot(x, cos(x), type = "l",
main = "Overlaying Charts",
ylab = "",
col = "red")
lines(x, sin(x), col = "blue")
legend("topleft", c("sin(x)", "cos(x)"), fill = c("blue", "red"))
```

**Output**

**How to add lines to a Plot in R**

To add the straight line to the existing plot, use the **abline()** function. The abline() is a built-in R method that takes four parameters, a, b, h, and v. The variables, **a** and **b** represent the slope and intercept. The **h** represents the y points for horizontal lines, and the **v** represents the x points for vertical lines.

```
x <- seq(1, 10, 2)
y1 <- x ^ 2
y2 <- x ^ 3
plot(x, y1, type = "l", col = "red")
lines(x, y2, col = "green")
legend("bottomright", inset = 0.05, c("Squares", "Cubes"),
lty = 1, col = c("red", "green"),
title = "Graph type")
abline(a = 4, b = 5, col = "blue")
abline(h = c(4, 6, 8), col = "red", lty = 2)
abline(v = c(4, 6, 8), col = "green", lty = 2)
```

**Output**

That’s all!

Krunal Lathiya is a seasoned Computer Science expert with over eight years in the tech industry. He boasts deep knowledge in Data Science and Machine Learning. Versed in Python, JavaScript, PHP, R, and Golang. Skilled in frameworks like Angular and React and platforms such as Node.js. His expertise spans both front-end and back-end development. His proficiency in the Python language stands as a testament to his versatility and commitment to the craft.