# Creating a matrix argument

Now we are going to use the Function Wizard to create a function with a matrix
argument.

### Add a matrix argument

Add a new argument **Z** and use the **matrix tool** to change it to a
2-dimensional argument. (Alternatively, you can use **Ctrl+2** as a
short-cut.)

Fill in the fields of Z as follows:

Type: |
Double[][] |

Name: |
Z |

Description: |
Matrix of Z values |

### Add the rest of the arguments

Add the remaining arguments, as shown below. You may find it convenient to use
the copy and paste argument commands to enter InterpY.

Type: |
Double |

Name: |
InterpX |

Description: |
X value at interpolation point |

Type: |
Double |

Name: |
InterpY |

Description: |
Y value at interpolation point |

When you've finished, the Function Wizard should look like this:

Click on the **OK** button to dismiss the Wizard and update the source code.

Next: Using matrix data >>