Input to Struct Array

I have been playing around with structs in Matlab all day and can't seem to grasp it. I have this code:

mystruct.color = 'red', 'green', 'red', 'red'; mystruct.angles = [30,60,90,180]; mystruct.row = [];

for i=1:3, mystruct.row[i] = input('Enter row: '); end

Where I want to input values for a row and have it stored in the row field in the mystruct struct but I keep getting this error:

Error: File: StructTest.m Line: 7 Column: 19 Unbalanced or unexpected parenthesis or bracket.

What I ultimately want to do is scan an image matrix and capture the rows of certain pixels but I need to understand this first.

Any help would be greatly appreciated.

Answer 1

[Image Analyst]

You need to use parentheses, not brackets: mystruct.row(i) not mystruct.row[i]

Secondly

mystruct.color = 'red', 'green', 'red', 'red';

probably doesn't do what you think it does. It does not make the color member of mystruct into a cell array with 4 elements. It assigns a string element and then basically does nothing with the string literals you define, so it's the same as these 4 completely separate lines:

mystruct.color = 'red';
'green';
'red';
'red';

Perhaps you want

mystruct.color = {'red', 'green', 'red', 'red'}; % Enclosed in braces

I have no idea what you want.

Answer 2

[Pamela]

Thanks for you reply.

I want to be able to enter values to the field in a for loop.

When I run:

for i=1:3, mystruct.row(i) = input('Enter row: '); end

I get:

Enter row: 2 Scalar structure required for this assignment.

Error in StructTest (line 7) mystruct.row(i) = input('Enter row: ');

But I want to be able to enter 3 values and have it be referenced as:

mystruct.row(1) = 1; (or any arbitrary values) mystruct.row(2) = 2; mystruct.row(3) = 3;

Do I have the wrong understanding on how Matlab structs work?

Answer 3

[Andrei Bobrov]

mystruct.color = {'red', 'green', 'red', 'red'};
mystruct.angles = [30,60,90,180];
for i1=1:3
    mystruct.row(i1) = input('Enter row: ');
end