Скачать или смотреть 3.5 Working with Functions

Learn how to create custom functions in Swift Calcs, including piece wise functions, and then how to use these functions later for your calculations.

A function is an expression dependent on one or more input variables to produce an output. A function does not have a single value, but instead returns a value depending upon the provided inputs. Functions can be defined using numbers, variables, and other functions. For example:

The first line defines a variable v. The next line defines a function y that depends on an input variable x, as well as the previously defined variable v. We also define a function g dependent on an input variable n, and the previously defined function y. In later lines, we can use functions as follows:

In the first example, we asked for the value of the function y assuming the input value for x was 42. The result is 22+42/21=24. In the second example, we again asked for the value of y assuming the input value for x was a variable m. Since m has not been defined, it is simply plugged in for x. If m had been defined, its value would have been used.

Functions can have more than one input, for example:

Auto-conversion from variables to functions
Swift Calcs will auto-convert your input to a function if it determines that was the probably intent. For example, if you define a variable f as:

Swift Calcs will check if the variable x that f depends on has already been defined. If so, then this entry is appropriate and the value of f is set based on the previously defined value of x. If x has not been set, however, Swift Calcs will assume that you intended to define f as a function of x, and it will transform your input to:

A message will appear advising you of the change, and it will include an undo link. Click that link (or use the keyboard shortcut Ctrl-Z) to override the automated transformation and return to your original entry.