How to stop data being overwritten in for loop?

I have a project where I'm creating an app where users can create a spatial model of a building (no of floors, rooms, dimensions ect.). I don't understand how to have my data not be overwritten by every for loop (a loop i created to input data for each floor).

Any help would be greatly appreciated.

noOfFloors=input('Enter number of Floors:');
if noOfFloors <=0
    disp('Enter valid number of floors');
    return;
end

for i=1:1:noOfFloors
    noOfRooms = input('Enter number of rooms on floor');
    if noOfRloors <=0
        disp('Enter valid number of rooms');
        return;
    end
    
    x=zeros(1,noOfRooms);
    y=zeros(1,noOfRooms);
    height=zeros(1,noOfRooms);
    width=zeros(1,noOfRooms);
    length=zeros(1,noOfRooms);
    area=zeros(1,noOfRooms);
    volume=zeros(1,noOfRooms);
    
    for j=1:1:noOfRooms
        roomType=menu('Choose Space','Residential','Educational','Office','Storage','Toilet');
        
        coordinates=inputdlg({'Enter x coordinates on this Floor','Enter y coordinates on this Floor'},'Data Input');
        x(j)=str2double(coordinates{1});
        y(j)=str2double(coordinates{2});
        
        dimensions=inputdlg({'Enter width','Enter height','Enter length'},'Data Input');
        width(j)=str2double(dimensions{1});
        height(j)=str2double(dimensions{2});
        length(j)=str2double(dimensions{3});
        area(j)=width(j)*length(j);
        volume(j)=width(j)*height(j)*length(j);
        
    end
    
end

Answer 1

[Stephen23]

Use a structure array, which allows you different numbers of rooms on each storey. A simple example:

NmS = 5; % number of storeys
Out = repmat(struct(),1,NmS);
for ii = 1:NmS
    NmR = 6; % number of rooms
    x = nan(1,NmR);
    y = nan(1,NmR);
    for jj = 1:NmR
        x(jj) = 3+jj+ii;
        y(jj) = 4+jj+ii;
    end
    Out(ii).area = x.*y;
    Out(ii).x = x;
    Out(ii).y = y;
end

Here I hardcoded the values, but you get the idea... Lets have a look at the second storey:

Out(2).area

ans = 1×6

42 56 72 90 110 132

Out(2).x

ans = 1×6

6 7 8 9 10 11

Out(2).y

ans = 1×6

7 8 9 10 11 12

See also: https://www.mathworks.com/help/matlab/matlab_prog/access-multiple-elements-of-a-nonscalar-struct-array.html

[Tom Hughes]

Thanks, that was a lot of help.

Answer 2

[Torsten]

In the outer loop, by initializing all vectors to 0, you overwrite all the settings done in the inner loop.

Furthermore, I guess that you will have to initialize all variables as

zeros(noOfFloors,noOfRooms)

instead of

zeros(1,noOfRooms)

and - as stated - this must be done in front of the outer loop.

[Tom Hughes]

Thanks for your answer mate. However when I initialize variables as

zeros(noOfFloors,noOfRooms)

I get the error 'Size inputs must be scalar'.