Declare function argument validation - MATLAB arguments (2024)

FAQs

What to do when MATLAB says not enough input arguments? ›

your function needs to be called with at least three input arguments. Therefore you must call it with exactly three input arguments. From the text of the error message you're likely calling it with fewer than three input arguments.

Function argument validation is a way to declare specific restrictions on function arguments. Using argument validation you can constrain the class, size, and other aspects of arguments without writing code in the body of the function to perform these tests.

Too many input arguments

This error message means that you are providing more input variables into a function than it is designed to handle.

You can pass multiple arguments as a varargin array by creating a Variant array, assigning each element of the array to the respective input argument. See Producing a COM Class for more information about mapping of input and output arguments.

MATLAB^® supports two syntaxes for passing name-value arguments. Use the name=value syntax to help identify name-value arguments for functions and to clearly distinguish names from values in lists of name-value arguments.

To ignore function outputs in any position in the argument list, use the tilde operator. For example, ignore the first output using a tilde. [~,name,ext] = fileparts(helpFile); You can ignore any number of function outputs using the tilde operator.

MATLAB lets you ignore arguments by passing a tilde character ( ~ ) in place of the argument. You can define a function that ignores unused positional arguments by adding a tilde character ( ~ ) in the arguments block corresponding to the position of the argument in the function signature.

You can specify the class, size, and other aspects of input variables in your entry-point MATLAB function by using arguments blocks to perform function argument validation. Specifying input types using arguments blocks supports: Numeric, logical, half, character, string, and enumeration data types.

The most basic use of validation functions is to ensure that documents are properly formed to fit your application's expectations. Without validation, you need to check for the existence of all fields on a document that your MapReduce or user-interface code needs to function.

As a rule of thumb, if a function takes too many arguments you should consider: Is the function doing too much? If so, perhaps you could split the logic in several, smaller functions instead. Group the arguments into structs in a way that feels logically consistent.

What does it mean when it says too many arguments for this function? ›

A formula must contain all of the required arguments, otherwise Excel displays "You've entered too few arguments for this function" alert. If you have entered more arguments than allowed by the formula's syntax, you will get "You've entered too many arguments for this function" error message.

The python input function takes only one argument as a parameter. This argument is optional.

Passing arguments by value

When an argument is passed by value, the C function receives a copy of the actual value of the argument. To specify that the argument should always be passed by value, use the keyword ByVal preceding the parameter declaration for that argument in the Declare statement for the C function.

arguments ... end declares input arguments for a function. The arguments block is optional. If you include one or more arguments blocks, they must appear before the first executable line of the function. MATLAB^® treats any argument block that is not labeled explicitly with Input or Output as an input block.

arguments ... end declares input arguments for a function. The arguments block is optional. If you include one or more arguments blocks, they must appear before the first executable line of the function. MATLAB^® treats any argument block that is not labeled explicitly with Input or Output as an input block.

x = input( prompt ) displays the text in prompt and waits for the user to input a value and press the Return key. The user can enter expressions, like pi/4 or rand(3) , and can use variables in the workspace. If the user presses the Return key without entering anything, then input returns an empty matrix.

To add input arguments to an app, open the app in App Designer and click Code View. Then click App Input Arguments in the Editor tab. This launches the App Details dialog box. Use the Input Arguments field in the dialog box to add or remove input arguments in the function signature of the startupFcn callback.

MATLAB lets you ignore arguments by passing a tilde character ( ~ ) in place of the argument. You can define a function that ignores unused positional arguments by adding a tilde character ( ~ ) in the arguments block corresponding to the position of the argument in the function signature.