MATLAB Central Newsreader - getting a list

getting a list

Isabel — Sun, 30 Nov 2008 19:34:02 -0500

How can I get matlab to give me a list as the answer to a function? For example
function [a,b]=add(T)
a=2*T
b=3*T
[2*T,3*T]
everytime I do something like that, it only gives me back the first element. So in this case it would give me as an answer only 2*T.
What I've been doing is this:
function z=add(T)
z(1)=2*T
z(2)=3*T
end
but I would like to know how to put a list as an output argument. Thanks!

Re: getting a list

Walter Roberson — Sun, 30 Nov 2008 19:52:36 -0500

Isabel wrote:
> How can I get matlab to give me a list as the answer to a function? For example
> function [a,b]=add(T)
> a=2*T
> b=3*T
> [2*T,3*T]
> everytime I do something like that, it only gives me back the first element. So in this case it would give me as an answer only 2*T.
> What I've been doing is this:
> function z=add(T)
> z(1)=2*T
> z(2)=3*T
> end
> but I would like to know how to put a list as an output argument. Thanks!

function z = add(T)
z = [2*T, 3*T]
end

--
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Please review questions before posting them. Be specific. Use examples of what you mean,
of what you don't mean. Specify boundary conditions, and data classes and value
relationships -- what if we scrambled your data or used -Inf, NaN, or complex(rand,rand)?

Re: getting a list

Ryan Ollos — Sun, 30 Nov 2008 23:52:02 -0500

"Isabel" <isabels29@hotmail.com> wrote in message <ggupr9$280$1@fred.mathworks.com>...
> What I've been doing is this:
> function z=add(T)
> z(1)=2*T
> z(2)=3*T
> end
> but I would like to know how to put a list as an output argument. Thanks!

Your function seems to work fine for me. I get z = [10 15] as the return argument. Maybe you have a conflict with the built-in add function. Run 'which add -all' and check if your function is being shadowed ... or just rename it.

Re: getting a list

Matt Fig — Mon, 01 Dec 2008 00:55:04 -0500

"Isabel" <isabels29@hotmail.com> wrote in message <ggupr9$280$1@fred.mathworks.com>...
> How can I get matlab to give me a list as the answer to a function? For example
> function [a,b]=add(T)
> a=2*T
> b=3*T
> everytime I do something like that, it only gives me back the first element. So in this case it would give me as an answer only 2*T.

I am going to guess you meant something different. Do you mean, "How do I call a function so that it will return several variables?" If so, say you have this function:

function [a,b]=add2(T) % Don't mask a built-in
a=2*T;
b=3*T;

Now at the command line call the function like this (for example):

>>[A,B]=add2(5)

You should have two new variables in your workspace. The variable 'A' has a value of 10 and the variable 'B' has a value of 15.

Re: getting a list

swgillan — Mon, 01 Dec 2008 06:26:52 -0500

On Nov 30, 11:34=A0am, "Isabel" <isabel...@hotmail.com> wrote:
> How can I get matlab to give me a list as the answer to a function? For e=
xample
> function [a,b]=3Dadd(T)
> a=3D2*T
> b=3D3*T
> [2*T,3*T]
> everytime I do something like that, it only gives me back the first eleme=
nt. So in this case it would give me as an answer only 2*T.
> What I've been doing is this:
> function z=3Dadd(T)
> z(1)=3D2*T
> z(2)=3D3*T
> end
> but I would like to know how to put a list as an output argument. Thanks!

when you have a multi-variable output, you have to call it using an
array of the output you want. Otherwise, if you just call with 1
variable, you only get the first condition back:

z =3D add(T) will only return the first output of your function
[x y] =3D add(T) will return both properly.