Unable to perform assignment because the left and right sides have a different number of elements.

Does anyone know why I get that failure: "Unable to perform assignment because the left and right sides have a different number of elements."

I can't see it. Thanks for your help.

%Files and Pics
data_list = dir('*.bmp');
%Zugreifen auf Ordner und BIlder und Namen zuweisen
name = {data_list.name};
%Konvertieren in Matrix
imBlack = imread("460_dunkel.bmp");
name(strcmp(name,"460_dunkel.bmp")) = []; % remove 460_dunkel.bmp
lambda = 0.633; %Wellenlänge Laser in um
Pixelgroesse = 4.65; %Pixelgroesse in um
for i = 1:22
    picture = imread(name{i});  %Einlesen des Bildes in Matrix
    current_name = name{i};
    zaxe = str2double(name{i}(1:3)); %Auslesen des z Wertes aus Dateinamen
    
    imBlack = double(imBlack);
    pictureS(:,:,i)=picture;    %speichert das aktuelle (i-te) 
    %Bild als 2D Matrix in der 3D Matrix (:,:,i)
    picture = double(picture);
    filtered = double(minus(picture,imBlack));
    
    %Ermittlung ROI
    ROI = im2double(filtered);
    ROIdiff = [1,1];
    ROIoffset =[0, 0];
    
    en_density = sum(sum((ROI)));
    %1.Moment
    [row,column] = size(ROI);
    first_Moment_X(i,1)=0;
    
    for y=1:row
        for x=1:column
            first_Moment_X(i,1) =first_Moment_X(i,1)+ x.*ROI(y,x);
        end
    end
    Schwerp_X = first_Moment_X./en_density;   
    Schwerpunkte_X(i) = Schwerp_X;
    
    first_Moment_Y(i,1)=0;
    for y=1:row
        for x=1:column
            first_Moment_Y(i,1) = first_Moment_Y(i,1) + y.*ROI(y,x);
        end
    end
    Schwerp_Y = first_Moment_Y./en_density;
    Schwerpunkte_Y(i) = Schwerp_Y;
    %2.Moment
    [row,column] = size(ROI);
    sec_Moment_X(i,1)=0;
    for y=1:row
        for x=1:column
            sec_Moment_X(i,1) = sec_Moment_X(i,1) + ((x-Schwerp_X).^2).*ROI(y,x);
        end
    end
    
    Sigma_X = sec_Moment_X./en_density;
    Sigma_X_plural(i) = Sigma_X;
    
    sec_Moment_Y(i,1) = 0;
    for y=1:row
        for x=1:column
            sec_Moment_Y(i,1) = sec_Moment_Y(i,1) + ((y-Schwerp_Y).^2).*ROI(y,x);
        end
    end
    Sigma_Y = sec_Moment_Y./en_density;
    Sigma_Y_plural(i) = Sigma_Y;
    
    sec_Moment_XY(i,1) = 0;
    for y=1:row
        for x=1:column
            sec_Moment_XY(i,1) = sec_Moment_XY(i,1) + (x-Schwerp_X).*(y-Schwerp_Y).*ROI(y,x);
        end
    end
    
    Sigma_XY = sec_Moment_XY./en_density;
    Sigma_XY_plural(i) = Sigma_XY;
    %Berechnung des Strahldurchmessers nach Formel 18 und 19 in Norm 
    dxPixel = 2*sqrt(2)*(sqrt(Sigma_X_plural + Sigma_Y_plural+sign(Sigma_X_plural-Sigma_Y_plural).*(sqrt(((Sigma_X_plural-Sigma_Y_plural).^2)+4*(Sigma_XY_plural.^2)))));
    dyPixel = 2*sqrt(2)*(sqrt(Sigma_X_plural + Sigma_Y_plural-sign(Sigma_X_plural-Sigma_Y_plural).*(sqrt(((Sigma_X_plural-Sigma_Y_plural).^2)+4*(Sigma_XY_plural.^2)))));
    dx(i,1) = dxPixel * Pixelgroesse;   %Umrechnung von Pixel in Mikrometer
    dy(i,1) = dyPixel * Pixelgroesse;   %Umrechnung von Pixel in Mikrometer
    dz(i,1) = zaxe; %Nur um alles am selben Fleck zu haben
end
%Plotten der einzelnen Bilder für dx
scatter(dz,dx,50,'x','MarkerFacecolor','none');
[dz,dx] = prepareCurveData(dz,dx);
hold on;
grid on;
[fitx,gofx]= fit(dz,dx,"poly2");
fithandle = plot(fitx);
set(fithandle,'color','[0 .7 .7]');
[fitxw,gofxw] = fit(dz,dx,'poly2','weights',1./dx);

[Torsten]

Which line ? Which assignment ?

[Bersin Tekmen]

@Torsten

Error in Laser_V2_Bersin_Sven_5_CR_2 (line 46)

Schwerpunkte_X(i) = Schwerp_X;

[Jan]

By the way, replace:

for y=1:row
   for x=1:column
       first_Moment_X(i,1) =first_Moment_X(i,1)+ x.*ROI(y,x);
   end
end

by

first_Moment_X(i,1) = sum((1:colum) .* ROI, 'all');   

[Bersin Tekmen]

@Jan can you explain that please?

[Jan]

@Bersin Tekmen: It is much easier to fix a code, when it is written as simple as possible. These two blocks of code do exactly the same. Compare it for the full program:

This part:

first_Moment_X(i,1)=0;
for y=1:row
    for x=1:column
        first_Moment_X(i,1) =first_Moment_X(i,1)+ x.*ROI(y,x);
    end
end
Schwerp_X = first_Moment_X./en_density;   
Schwerpunkte_X(i) = Schwerp_X;

first_Moment_Y(i,1)=0;
for y=1:row
    for x=1:column
        first_Moment_Y(i,1) = first_Moment_Y(i,1) + y.*ROI(y,x);
    end
end
Schwerp_Y = first_Moment_Y./en_density;
Schwerpunkte_Y(i) = Schwerp_Y;

[row,column] = size(ROI);
sec_Moment_X(i,1)=0;
for y=1:row
    for x=1:column
        sec_Moment_X(i,1) = sec_Moment_X(i,1) + ((x-Schwerp_X).^2).*ROI(y,x);
    end
end

Sigma_X = sec_Moment_X./en_density;
Sigma_X_plural(i) = Sigma_X;

sec_Moment_Y(i,1) = 0;
for y=1:row
    for x=1:column
        sec_Moment_Y(i,1) = sec_Moment_Y(i,1) + ((y-Schwerp_Y).^2).*ROI(y,x);
    end
end
Sigma_Y = sec_Moment_Y./en_density;
Sigma_Y_plural(i) = Sigma_Y;

sec_Moment_XY(i,1) = 0;
for y=1:row
    for x=1:column
        sec_Moment_XY(i,1) = sec_Moment_XY(i,1) + (x-Schwerp_X).*(y-Schwerp_Y).*ROI(y,x);
    end
end

Sigma_XY = sec_Moment_XY./en_density;
Sigma_XY_plural(i) = Sigma_XY;

and this one:

xv = (1:column);
yv = (1:row).';

first_Moment_X(i,1) = sum(xv .* ROI, 'all');
Schwerp_X           = first_Moment_X ./ en_density;   
Schwerpunkte_X(i)   = Schwerp_X;

first_Moment_Y(i,1) = sum(yv .* ROI, 'all');
Schwerp_Y           = first_Moment_Y ./ en_density;
Schwerpunkte_Y(i)   = Schwerp_Y;

sec_Moment_X(i,1) = sum((xv - Schwerp_X).^2 .* ROI, 'all');
Sigma_X_plural(i) = sec_Moment_X./en_density;

sec_Moment_Y(i,1) = sum((yv - Schwerp_Y).^2 .* ROI, 'all');
Sigma_Y_plural(i) = sec_Moment_Y ./ en_density;

sec_Moment_XY(i,1) = sum(xv - Schwerp_X) .* (yv - Schwerp_Y) .* ROI, 'all');
Sigma_XY_plural(i) = sec_Moment_XY ./ en_density;

Are equivalent. I find the 2nd one much easier to read.

Answer 1

[Jan]

    Schwerp_X = first_Moment_X./en_density;   
    Schwerpunkte_X(i) = Schwerp_X;

first_Moment_X is a vector, so is Schwerp_X, but Schwerpunkte_X(i) is a scalar.

Maybe you want:

    Schwerp_Y = first_Moment_Y(i) / en_density;
    Schwerpunkte_Y(i) = Schwerp_Y;

[Bersin Tekmen]

@Jan Unable to perform assignment because the size of the left side is 1-by-1 and the size of the right side is 1-by-2.

Error in Laser_V2_Bersin_Sven_5_CR_2 (line 95)

dx(i,1) = dxPixel * Pixelgroesse; %Umrechnung von Pixel in Mikrometer

Your option worked best for me, But now i get that failure message.

[Torsten]

It's the same kind of error as before.

dx(i,1) = dxPixel(i,1) * Pixelgroesse;   %Umrechnung von Pixel in Mikrometer
dy(i,1) = dyPixel(i,1) * Pixelgroesse;   %Umrechnung von Pixel in Mikrometer

Also in the lines before you'd better use

dxPixel(i,1) = 2*sqrt(2)*(sqrt(Sigma_X_plural(i,1) + Sigma_Y_plural(i,1)+sign(Sigma_X_plural(i,1)-Sigma_Y_plural(i,1)).*(sqrt(((Sigma_X_plural(i,1)-Sigma_Y_plural(i,1)).^2)+4*(Sigma_XY_plural(i,1).^2)))));
dyPixel(i,1) = 2*sqrt(2)*(sqrt(Sigma_X_plural(i,1) + Sigma_Y_plural(i,1)-sign(Sigma_X_plural(i,1)-Sigma_Y_plural(i,1)).*(sqrt(((Sigma_X_plural(i,1)-Sigma_Y_plural(i,1)).^2)+4*(Sigma_XY_plural(i,1).^2)))));

[Bersin Tekmen]

@Torsten I already thought so an tried the same like you did here. But then I got this error:

Index in position 1 exceeds array bounds. Index must not exceed 1.

Error in Laser_V2_Bersin_Sven_5_CR_2 (line 92)

dxPixel(i,1) = 2*sqrt(2)*(sqrt(Sigma_X_plural(i,1) + Sigma_Y_plural(i,1)+sign(Sigma_X_plural(i,1)-Sigma_Y_plural(i,1)).*(sqrt(((Sigma_X_plural(i,1)-Sigma_Y_plural(i,1)).^2)+4*(Sigma_XY_plural(i,1).^2)))));

[Bersin Tekmen]

I changed like that now:

%Berechnung des Strahldurchmessers nach Formel 18 und 19 in Norm 
dxPixel(i) = 2*sqrt(2)*(sqrt(Sigma_X_plural(i) + Sigma_Y_plural(i)+sign(Sigma_X_plural(i)-Sigma_Y_plural(i)).*(sqrt(((Sigma_X_plural(i)-Sigma_Y_plural(i)).^2)+4*(Sigma_XY_plural(i).^2)))));
dyPixel(i) = 2*sqrt(2)*(sqrt(Sigma_X_plural(i) + Sigma_Y_plural(i)-sign(Sigma_X_plural(i)-Sigma_Y_plural(i)).*(sqrt(((Sigma_X_plural(i)-Sigma_Y_plural(i)).^2)+4*(Sigma_XY_plural(i).^2)))));
dx(i,1) = dxPixel(i) * Pixelgroesse;   %Umrechnung von Pixel in Mikrometer
dy(i,1) = dyPixel(i) * Pixelgroesse;   %Umrechnung von Pixel in Mikrometer
dz(i,1) = zaxe(i,1); %Nur um alles am selben Fleck zu haben

No I get the following message:

Index exceeds the number of array elements. Index must not exceed 1.

Error in Laser_V2_Bersin_Sven_5_CR_2 (line 97)

dz(i) = zaxe(i); %Nur um alles am selben Fleck zu haben

[Jan]

zaxe is a scalar. Why do you use "zaxe(i,1)"?

[Bersin Tekmen]

@Jan bc normally zaxe is a vektor. Let me explain: I have some images. The name of the images is the distance between the laser spot and the camera (so I got 22 images). "zaxe" is in my programm all does names, converted into double ("zaxe = str2double(name{i}(1:3))"). In the current code every zaxe will be overwritten. I thought with "zaxe(i,1)" I can prevent that.

Just to make you understand "name" and "zaxe" here a program part:

You can see "name" is a list of data (images).

%Files and Pics
data_list = dir('*.bmp');
%Zugreifen auf Ordner und BIlder und Namen zuweisen
name = {data_list.name};
%Konvertieren in Matrix
imBlack = imread("460_dunkel.bmp");
name(strcmp(name,"460_dunkel.bmp")) = []; % remove 460_dunkel.bmp
lambda = 0.633; %Wellenlänge Laser in um
Pixelgroesse = 4.65; %Pixelgroesse in um

Here I convert the name (which is a string number) to double:

zaxe = str2double(name{i}(1:3)); %Auslesen des z Wertes aus Dateinamen

[Jan]

@Bersin Tekmen: I cannot follow you. After

zaxe = str2double(name{i}(1:3));

zaxe is a scalar. What does it mean that it is "a vector normally"? In your code it is not.

If you want to store the value of zaxe in each iteration, use:

zaxe(i, 1) = str2double(name{i}(1:3));

Then you cann access zaxe(i,1) later on also.

Answer 2

[Torsten]

Only

Schwerpunkte_X(i) = Schwerp_X(i,1);

is possible since "Schwerpunkte_X(i)" is a scalar (one single value) which cannot be set to the vector Schwerp_X.

Same for the following 4 settings

Schwerpunkte_Y(i) = Schwerp_Y;
Sigma_X_plural(i) = Sigma_X;
Sigma_Y_plural(i) = Sigma_Y;
Sigma_XY_plural(i) = Sigma_XY;