How to add zero at the very beginning of my column matrix?

Hello everyone,

I am plotting a stress-strain curve and would like to insert a point at the origin. I have tried using the zeros function but have not found any luck yet. I keep getting an error stating that the "dimensions of arrays being concatenated are not consistent". If you can please help me resolve this issue, it'll be greatly appreciated, thanks in advance.

CODE:

%% Stress & Strain Curve from Force Actuator

exist('DIC_test.08.02.xlsx','file');
Data = importdata('DIC_test.08.02.xlsx');

Time = Data(:,1); Force = Data(:,2); Displacement = Data(:,3);

Area = (6.26e-3)*(1.57e-3); Lo = 27.07;

Eng_Stress = Force/Area; 
Eng_Stress(Eng_Stress < 0) = NaN;
Eng_Stress = Eng_Stress(327:end);
Eng_Stress = [zeros(1), Eng_Stress];   % This is the column I am trying to add a zero at the very beginning

Eng_Strain = (Displacement)/Lo; 
Eng_Strain = Eng_Strain - Eng_Strain(327);
Eng_Strain = Eng_Strain(327:end);
Eng_Strain = zeros(1) + Eng_Strain;   % This one I think is okay

Percent_Elongation = (Displacement(end)/Lo)*100;

E_FA = ((Eng_Stress(600)-Eng_Stress(500))/(Eng_Strain(600)-Eng_Strain(500)))/(1e9) 

figure(1)
plot(Eng_Strain,Eng_Stress,'r')
ytickformat('%12.2f')
ax = gca;
ax.YAxis.Exponent = 6;
hold on 
plot(Eng_Strain(500),Eng_Stress(500),'b *')
plot(Eng_Strain(600),Eng_Stress(600),'b *')
grid on 
title('Stress v. Strain Force Actuator'); xlabel('Strain Measured in mm/mm'); ylabel('Stress measured in Pa')

Answer 1

[Adam Danz]

Use a semicolon instead of a comma. The variable 'Eng_Strain' is a column vector so you need to vertically concatenate the zero with the vector.

Eng_Stress = [zeros(1); Eng_Stress];    
%                     ^

Or just

Eng_Stress = [0; Eng_Stress];