# 2.4.2.4 Using Origin C Functions

To extend the functions, you can also define an Origin C function (see Creating and Using Origin C Code for details) which returns a single value, and call the function from command window. For example,

1. Open Code Builder by menu View: Code Builder.
2. In Code Builder, create a new *.c file by menu File: New. In the New File dialog, give a file name, MyFuncs for example, and click OK.
3. Start a new line at the end of this new file, and add the following code.
4. double MyFunc (double x)
{
return sin(x) + cos(x);
}
5. Click menu item Build: Build to compile and link the file.
6. If no error, the function defined above is now available in LabTalk. Run the following script in the Command Window.
7. newbook;  // create a new workbook
col(A) = data(1, 32);  // fill row number
col(B) = MyFunc(col(A));  // call the Origin C function, result is put to column B