# Get a List of points obtained by Interpolation in R Programming – spline() and splinefun() Function

In R programming, `spline()`

and `splinefun()`

function is used to create a list of points obtained by interpolation. It performs cubic spline interpolation of given data points.

Syntax:

spline(x, y, method)

and

splinefun(x, y, method)

Parameters:x, y:represents vectors giving the points for interpolationmethod:represents the type of spline interpolation to be used

To know about more optional parameters of both the functions, use below command in console:

help("spline")

**Example 1:**

`# Coordinates` `n <- 100` `x <- 1:n` `y <- ` `rnorm` `(n)` ` ` `# Output to be present as PNG file` `png` `(file = ` `"splineGFG.png"` `)` ` ` `# Spline() function` `plot` `(x, y, main = ` `"spline() function"` `)` `lines` `(` `spline` `(x, y))` ` ` `# Saving the file` `dev.off` `()` |

**Output:**

**Example 2:**

`# Coordinates` `n <- 100` `x <- 1:n` `y <- ` `sin` `((x-0.5)*` `pi` `)` ` ` `# Output to be present as PNG file` `png` `(file = ` `"splinefunGFG.png"` `)` ` ` `f <- ` `splinefun` `(x, y)` `curve` `(` `f` `(x))` ` ` `# Saving the file` `dev.off` `()` |

**Output:**