Unable to perform assignment because brace indexing is not supported for variables of this type.

How should I define my variables before the loop to get this to work??? Please help I am lost!

clear;clc;
%%
fish = input('How much do your fish weigh(in kg as a vector[])? ');
grade = char(1,length(fish));
price = char(1,length(fish));
use = char(1,length(fish)); % preallocate cell array.
for k = 1: length(fish)
    if fish(k) >= 30
        grade{k} = 'S';
        price{k} = 20*fish;
        use{k} = 'Whole Fish';
    elseif fish(k) > 20
        grade{k} = 'A';
        price{k} = 15*fish;
        use{k} = 'Fillet';
    elseif fish(k) > 10
        grade{k} = 'B';
        price{k} = 6*fish;
        use{k} = 'Canning';
    elseif fish(k) > 5
        grade{k} = 'C';
        price{k} = 4*fish;
        use{k} = 'Pet Food';
    else
        grade{k} = 'D';
        price{k} = 1*fish;
        use{k} = 'Fish Extracts';
    end
end
totalPrice = sum(price(:));
fprintf('Grade    Use     Weight    Total Income\n')
fprintf('%4c     %15c      %5d kg         $%-d\n',[grade;use;fish;price])
fprintf('       Total Income: $%d\n',totalPrice)

[Rik]

This time I edited your question for you. Next time, please use the tools explained on this page to make your question more readable.

Answer 1

[Matt J]

grade = cell(1,length(fish));
price = cell(1,length(fish));
use = cell(1,length(fish)); % preallocate cell array.

Also, these lines should be

        grade{k} = 'D';    %'k' not 'i'
        price{k} = 1*fish;

[Rik]

price{k} = 1*fish(k)

Although using a cell is probably a bad idea because of the sum later on.

Answer 2

[Walter Roberson]

grade = char(1,length(fish));

That is going to make grade into a character vector.

        grade{k} = 'S';

That needs grade to be a cell array of character vectors.

        grade(k) = 'S';

should work.