"index exceeds matrix dimensions" error.

I keep getting the "index exceeds matrix dimensions" error when I get to problem 3 with my code. If i were to run the code separately and using clc and clear, it works fine. I also have to use clc and clear every time i want to run my code. Is there any way I can run it without doing so? Thank you! This is my code:

    %Problem 1
  disp('Answers to Problem 1: ')
  fprintf('\n')
N = input('Please enter an integer: ');
while (N < 0 ||(N~=fix(N)));
        disp('You have entered an invalid integer. Please try again. ')
        N = input('Please enter an integer: ');
end

a = sum(1:N);
fprintf('The sum of integers from 1 to %.0f is: %.2f\n ',N,a)

sum = 0;
for a = 1:N;
sum = sum+a;
end
fprintf('The sum of integers 1 to %.0f is: %.2f\n ',N,sum);

%Problem 2

fprintf('\n')
disp('Answers to Problem 2: ')
fprintf('\n')

K = input('Please enter an integer: ');
product = 1;
while (K < 0 ||(K~=fix(K)))
    disp('You have entered an invalid number. Please try again. ')
    K = input('Please enter an integer: ');
end

y = prod(1:K);
fprintf('The product of integers 1 to %.0f is: %.1f\n ',K,y)
for y = [1:K];
product = product*y;
end
fprintf('The product of integers 1 to %.0f is: %.1f\n',K,product)

%Problem 3

fprintf('\n')
disp('Answers to Problem 3: ')
fprintf('\n')

Vector = input('Enter a vector while using [] around the numbers: ');
b = sum(Vector);
fprintf('The sum of the elements in the vector = %.3f\n ',b)

sumvec = 0;
w = length(Vector);
for e = 1:w
    sumvec = sumvec + Vector(e);
end
fprintf('The sum of the elements in the vector = %.3f\n ',sumvec)

%Problem 4

fprintf('\n')
disp('Answers to Problems 4: ')
fprintf('\n')

P = input('Please enter a value for the first number: ');
Q = input('Please enter a value for the second number: ');
    if (P < 0||(P~=fix(P)||(Q~=fix(Q)||(P > Q))))
        disp('Please enter valid integers.')
        fprintf('\n')
        disp('I.E. Whole numbers & first number must be less than the second number.')
        P = input('Please enter a value for the first number: ');
        Q = input('Please enter a value for the second number: ');
    else
        t = prod(P:Q);
        fprintf('The product of %d to %d is: %d\n ',P,Q,t)
        product = 1;
        for u = [P:Q];
            product = product*u;
        end
        fprintf('The product of %d to %d is: %d\n ',P,Q,product)
    end

%Problem 5

fprintf('\n')
disp('Answer to Problem 5: ')
fprintf('\n')

for k = 1:4
    for t = 4:-1:k
        fprintf('*')
    end
    fprintf('\n')
end
for k = 4:-1:1
    for t = 4:-1:k
        fprintf('^')
    end
    fprintf('\n')
end

Answer 1

[Walter Roberson]

In problem 1, you defined "sum" as a variable. Then in problem 3, you attempt to use "sum" as a function.

Answer 2

[Sean de Wolski]

It probably means that whatever variable you're using to index is already defined elsewhere and not redefined in your code. Type

 dbstop if error

and inspect the variables when it errors out. You don't need clc and you should be able to use

 clearvars

instead of clear; just insert it at the top of the script.

Answer 3

[Daniel]

Ah, thank you walter! i changed the sum variable to a different name and it worked. and thank you sean! i could also just write "clear" before each code in each problem and that would also take care of my problem.

Answer 4

[maged al-dhaeebi]

Index exceeds matrix dimensions.

I have the same probelm in my code hwo to solve this

my code it :

FolderNames={'Data0', 'Data45','Data90','Data135','Data180','Data225','Data270','Data315'}

FolderIndx=1
SaveFileName=strcat('ProcessData',num2str(FolderIndx));
SaveImageFileName=strcat('ImageData',num2str(FolderIndx));

AngleAr=45*[4,5,6,7,0,1,2,3]';

FoldName=FolderNames{FolderIndx}
       list=ls(FoldName)

      for FrqIndx=1 : 3
           FileName=strcat(FoldName,'\', list(FrqIndx+2,:));   
          StrData=load(FileName);
          [XData,YData,ZData,ImageData]=ProcessRawData(StrData,AngleAr,FolderIndx)
          SpotsDataX{FrqIndx}=XData;
          SpotsDataY{FrqIndx}=YData;
          SpotsDataZ{FrqIndx}=ZData;
          Images{FrqIndx}=ImageData;
          size(Images)
      end

save (SaveFileName,'SpotsDataX','SpotsDataY','SpotsDataZ');
save (SaveImageFileName,'Images');

[Walter Roberson]

Which line does the problem occur on?

Your code assumes that each of those folders already contains at least 5 directory entries including "." and ".." (which are not promised to be the first two entries, by the way.) If one of the folders contains fewer entries then you would get index out of range accessing list(FrqIndx+2,:)

Answer 5

[Manjiree Waikar]

I have this error in my code as

Index exceeds matrix dimensions. Error in clusteredit (line 21) green = imIDX(:,:,2); % Green channel

Please help me how to tackle this error.

My code is-

clear all; 

newImageRGB = imread('p2_left_norm_1.bmp'); 

figure; 

imshow(newImageRGB); 

title('Original image'); 

grayImage = rgb2gray(newImageRGB); 

figure; 

imshow(grayImage); 

title('grayscale image'); 

afterWiener = wiener2(grayImage,[6 6]); 

figure; 

imshow(afterWiener); 

title('Wiener filter'); 

imData=reshape(afterWiener,[],1); 

imData=im2double(imData); 

[IDX mn]=kmeans(imData,3); 

imIDX=reshape(IDX,size(afterWiener));

red = imIDX(:,:,1); % Red channel 

green = imIDX(:,:,2); % Green channel 

blue = imIDX(:,:,3); % Blue channel 

a = zeros(size(imIDX, 1), size(imIDX, 2)); 

just_red = cat(3, red, a, a); 

just_green = cat(3, a, green, a); 

just_blue = cat(3, a, a, blue); 

back_to_original_img = cat(3, red, green, blue); 

figure, 

imshow(just_red), 

title('Red channel') 

figure, 

imshow(just_green), 

title('Green channel') 

figure, 

imshow(just_blue), 

title('Blue channel')

[Walter Roberson]

Looking in reverse order, you have

green = imIDX(:,:,2); % Green channel

after

imIDX=reshape(IDX,size(afterWiener));

after

afterWiener = wiener2(grayImage,[6 6]);

after

grayImage = rgb2gray(newImageRGB);

So you are taking an RGB image, transforming it to gray, doing a wiener2 transform on it, getting a 2D result. The size of the 2D result is used to reshape the matrix IDX, so the result of the reshape is going to be 2D. You then try to index the third dimension of that 2D matrix.

Possibly at some point after reshaping IDX, you wanted to use those indices to index into the original color image, such as

R = newImageRGB(:,:,1);
G = newImageRGB(:,:,2);
B = newImageRGB(:,:,3);
red = R(IDX);
green = G(IDX);
blue = B(IDX);