Function [output]=F​unctionNam​e(input)

I don't understand why sometimes a pair of brackets is used when a function is created. I have seen it in two cases:

1. the output is empty 2. the output is logical

Can someone please help me to clarify the scope of using a pair of brackets for the output when a function is created?

Answer 1

[per isakson]

Go to Create Functions in Files and look for Syntax for Function Definition. It says:

Output arguments (optional)

If your function returns one output, you can specify the output name after the function keyword. [...] If your function returns more than one output, enclose the output names in square brackets.

function [one,two,three] = myFunction(x)

The brackets are optional with zero and one output.

The Matlab template includes the brackets

function [ output_args ] = Untitled( input_args )
    %UNTITLED Summary of this function goes here
    %   Detailed explanation goes here
end

I guess, this template encourage the use of brackets with zero and one output.

[Jan]

Explicitly:

function [] = Untitled( input_args )
% is equivalent to:
function Untitled( input_args )

And

function [out] = Untitled( input_args )
% is equivalent to:
function out = Untitled( input_args )

[Lisa Lee]

Thank you. This helps to clarify things for me.

Answer 2

[Jaya Agnihotri]

function mfunc = minmod((ur-ul)/Delta_x,(ul-ul1)/Delta_x)

mfunc=0;

if sign(v)==sign(w)

mfunc=sign(v).*min(abs(v,w));

end

how to define this function in a right way?

[Steven Lord]

In a function definition the input arguments must be variable names, not expressions.

% define
function mfunc = minmod(v, w)
% Do stuff to define mfunc here
end

In a function call you can pass expressions in and the results of those expressions are assigned to the variables listed in the definition.

% call
theOutput = minmod(1:10, sind(1:10))
% In this particular call, v will be 1:10 and w will be sind(1:10)