MATLAB Central Newsreader - How to assign a vector to a structure?

How to assign a vector to a structure?

Kian — Sun, 14 Jun 2009 23:37:01 -0400

I have a structure and an array of values that I'd like to assign to that structure. Example:

I have 10 electrodes. Each one have a number and each one has a bankID, etc. The electrode numbers go, for example, 1:10. The bankID goes, 1 & 2 for each 5 electrodes.

numbers = 1:10;
bankID = [1, 1, 1, 1, 1, 2, 2, 2, 2, 2];

How do I assign these two arrays to these structures without a for-loop?
myStruct.electrode.number
myStruct.electrode.bankID

I'd think a command like this would do the job, but it doesn't:

myStruct.electrode(1:10).number = numbers;
myStruct.electrode(1:10).bankID = bankID;

So instead, I use:

for i = 1:10
   myStruct.electrode(i).number = numbers(i);
   myStruct.electrode(i).bankID = bankID(i);
end

I have a feeling there should be a solution involving brackets, but I can't figure it out. Alternatively, somehow converting the arrays (i.e. numbers and bankID) to structures may also do the job.

Thanks in advance!

Re: How to assign a vector to a structure?

Sadik — Mon, 15 Jun 2009 00:22:01 -0400

Hi Kian,

I tried to make it one line:

s = cell2struct([mat2cell((1:10)',10,1) mat2cell([ones(5,1);2*ones(5,1)],10,1)],{'number','bankID'},2);

"Kian " <kian.torab@utah.edu> wrote in message <h141it$d34$1@fred.mathworks.com>...
> I have a structure and an array of values that I'd like to assign to that structure. Example:
>
> I have 10 electrodes. Each one have a number and each one has a bankID, etc. The electrode numbers go, for example, 1:10. The bankID goes, 1 & 2 for each 5 electrodes.
>
> numbers = 1:10;
> bankID = [1, 1, 1, 1, 1, 2, 2, 2, 2, 2];
>
> How do I assign these two arrays to these structures without a for-loop?
> myStruct.electrode.number
> myStruct.electrode.bankID
>
> I'd think a command like this would do the job, but it doesn't:
>
> myStruct.electrode(1:10).number = numbers;
> myStruct.electrode(1:10).bankID = bankID;
>
> So instead, I use:
>
> for i = 1:10
> myStruct.electrode(i).number = numbers(i);
> myStruct.electrode(i).bankID = bankID(i);
> end
>
> I have a feeling there should be a solution involving brackets, but I can't figure it out. Alternatively, somehow converting the arrays (i.e. numbers and bankID) to structures may also do the job.
>
> Thanks in advance!
>

Re: How to assign a vector to a structure?

Kian — Mon, 15 Jun 2009 03:56:01 -0400

Sadik,

Thanks for your response, but that doesn't achieve what I wanted to do. What you did is done by:

s.number = numbers';
s.bankID = bankID';

I want the following:

s(1).number = 1
s(3).bankID = 1
s(7).bankID = 2
and so on...

Thanks!
Kian

Re: How to assign a vector to a structure?

Sadik — Mon, 15 Jun 2009 04:20:17 -0400

You are right, sorry. This one should work:

s = struct('number', mat2cell((1:10)',ones(10,1),1), 'bankID', mat2cell([ones(5,1);2*ones(5,1)],ones(10,1),1));

"Kian " <kian.torab@utah.edu> wrote in message <h14goh$6lc$1@fred.mathworks.com>...
> Sadik,
>
> Thanks for your response, but that doesn't achieve what I wanted to do. What you did is done by:
>
> s.number = numbers';
> s.bankID = bankID';
>
> I want the following:
>
> s(1).number = 1
> s(3).bankID = 1
> s(7).bankID = 2
> and so on...
>
> Thanks!
> Kian

Re: How to assign a vector to a structure?

Bruno Luong — Mon, 15 Jun 2009 06:53:01 -0400

"Kian " <kian.torab@utah.edu> wrote in message <h141it$d34$1@fred.mathworks.com>...
> I have a structure and an array of values that I'd like to assign to that structure. Example:
>
> I have 10 electrodes. Each one have a number and each one has a bankID, etc. The electrode numbers go, for example, 1:10. The bankID goes, 1 & 2 for each 5 electrodes.
>
> numbers = 1:10;
> bankID = [1, 1, 1, 1, 1, 2, 2, 2, 2, 2];
>
> How do I assign these two arrays to these structures without a for-loop?
> myStruct.electrode.number
> myStruct.electrode.bankID
>
> I'd think a command like this would do the job, but it doesn't:
>
> myStruct.electrode(1:10).number = numbers;
> myStruct.electrode(1:10).bankID = bankID;
>
> So instead, I use:
>
> for i = 1:10
> myStruct.electrode(i).number = numbers(i);
> myStruct.electrode(i).bankID = bankID(i);
> end
>

If your struct exists already, assign in one shot can be done by:

c=num2cell(numbers); [myStruct.electrode(1:10).number]=deal(c{:});
c=num2cell(bankID ); [myStruct.bankID (1:10).number]=deal(c{:});
clear c

% Bruno

% Bruno

Re: How to assign a vector to a structure?

Kian — Mon, 15 Jun 2009 21:04:02 -0400

Thanks again, Bruno! Exactly what I was looking for. I knew brackets were involved somehow.

Re: How to assign a vector to a structure?

Matt — Mon, 15 Jun 2009 21:19:04 -0400

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <h14r4d$9vh$1@fred.mathworks.com>...

> If your struct exists already, assign in one shot can be done by:
>
> c=num2cell(numbers); [myStruct.electrode(1:10).number]=deal(c{:});
> c=num2cell(bankID ); [myStruct.bankID (1:10).number]=deal(c{:});
> clear c

Bruno- I think this will work even if your struct doesn't already exist...?

Re: How to assign a vector to a structure?

Matt — Mon, 15 Jun 2009 21:21:01 -0400

"Kian " <kian.torab@utah.edu> wrote in message <h16d02$c4o$1@fred.mathworks.com>...
> Thanks again, Bruno! Exactly what I was looking for. I knew brackets were involved somehow.

Bear in mind that all the solutions offered here call M-functions (num2cell, mat2cell, etc...) that use for-loops internally. So you are not really avoiding for loops, only the keystrokes needed to write them yourself.