Last Modified: June 25, 2019

Performs one-dimensional interpolation by using the linear interpolation method.

A Boolean that specifies whether the values of the independent variable increase monotonically with the index.

True | The values of the independent variable increase monotonically with the index. This node does not sort x or reorder y. |

False | The values of the independent variable does not increase monotonically with the index. This node sorts x to be in ascending order and reorders y accordingly. |

**Default: **False

Tabulated values of the dependent variable.

Tabulated values of the independent variable. The length of **x** must equal the length of **y**.

Values of the independent variable at which this node computes the interpolated values of the dependent variables.

This input accepts a double-precision, floating-point number or a 1D array of double-precision, floating-point numbers.

Number of times that this node interpolates values repeatedly and evenly between each **x** element to generate **xi used**. **ntimes** determines the locations of the interpolation values.

This input yields interpolated values between every **y** element when **xi** is empty. The node ignores **ntimes** if you wire the **xi** input.

This input is available only if you wire an array of double-precision, floating-point numbers to **xi**.

**Default: **1

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an **error in** input and an **error out** output so that the node can respond to and communicate errors that occur while code is running. The value of **error in** specifies whether an error occurred before the node runs. Most nodes respond to values of **error in** in a standard, predictable way.

**Default: **No error

Interpolated values that correspond to the independent variable values.

This output can return a double-precision, floating-point number or a 1D array of double-precision, floating-point numbers.

Values of the independent variable at which this node computes interpolated values of the dependent variable.

This output is available only if you wire an array of double-precision, floating-point numbers to **xi**.

If **xi** is empty, **xi used** returns 2^{ntimes} *(*N* - 1) + 1 points with (2^{ntimes} - 1) points located evenly between each two adjacent elements in **x**, where *N* is the length of **x**. If you wire the **xi** input, **xi used** equals **xi**.

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

**error in** input and an **error out** output so that the node can respond to and communicate errors that occur while code is running. The value of **error in** specifies whether an error occurred before the node runs. Most nodes respond to values of **error in** in a standard, predictable way.

The linear interpolation method sets the interpolated values to points along the line segments connecting the **x** and **y** data points.

With the linear interpolation method, this node interpolates **yi** on the line segment that connects the two points (*x*_{j}, *x*_{j + 1}) when **xi** is located between the two points (*x*_{j}, *x*_{j + 1}) in **x**, as shown in the following figure.

In the previous figure, the following equation is true:

${L}_{j}\left(x\right)={y}_{j}+\frac{{y}_{j+1}-{y}_{j}}{{x}_{j+1}-{x}_{j}}(x-{x}_{j})$

**Where This Node Can Run: **

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application