MATLAB: How to fix this error, please need help!

debugerrorhelpmaximum variablerank deficient

ERROR:
Warning: Rank deficient, rank = 0, tol =           inf. 
> In Lab4_k_s (line 46)
 Warning: Rank deficient, rank = 0, tol =           inf. 
> In Lab4_k_s (line 50)
Maximum variable size allowed by the program is exceeded.
Error in Lab4_k_s (line 69)
X1 = [min(x1):1e-3:max(x1)]';
 
>>
CODE:
%These commands clear the workspace and command window, in that order.
clear
clc
% Measured masses of spring 1, 2 and 3 measured in meters(m).
M1=[0 .1 .2 .3 .4 .5 .6 .7 .8 .9]';
M2=[0 .05 .1 .15 .2 .25 .3 .35 .4 .45]';
M3=[.05 .07 .09 .11 .13 .15 .17 .19 .21 .23]';
% Measured distances of spring 1, 2, and 3 measured in kilograms(kg).
L1=[.075 .085 .095 .105 .115 .125 .135 .145 .155 .165]';
L2=[.11 .145 .185 .225 .265 .305 .345 .375 .415 .455]';
L3=[.365 .455 .515 .585 .655 .735 .785 .885 .945 .995]';
g=(9.81);
L01=.19
L02=.08
L03=.1
x1 = ((1) ./ (M1 .* g));
y1 =((1) ./ (L1-L01));
x2 = ((1) ./ (M2 .*g));
y2 =((1) ./ (L2-L02));
x3 = ((1) ./ (M3 .* g));
y3 =((1) ./ (L3-L03));
G1= ones(length(x1), 1);
% G(:, 1) = b;

G1(:, 2) = x1;
k1 = G1 \ y1
G2 = ones(length(x2), 1);
G2(:, 2) = x2;
k2 = G2 \ y2
G3= ones(length(x3), 1);
% G(:, 1) = b;
G3(:, 2) = x3;
k3 = G3 \ y3
% uncertainties
sigma1 = sqrt(sum((y1-G1*k1).^2)./(length(x1)-2));
sigma2 = sqrt(sum((y2-G2*k2).^2)./(length(x2)-2));
sigma3 = sqrt(sum((y3-G3*k3).^2)./(length(x3)-2));
se11 = sigma1.*sqrt(1./((length(x1)+mean(x1)^2/((length(x1)-1)*std(x1)^2))));
se12 = sigma2.*sqrt(1./((length(x2)+mean(x2)^2/((length(x2)-1)*std(x2)^2))));
se13 = sigma3.*sqrt(1./((length(x3)+mean(x3)^2/((length(x3)-1)*std(x3)^2))));
se21 = sigma1.*sqrt(1./((length (x1)-1)*std(x1)^2));
se22 = sigma2.*sqrt(1./((length (x2)-1)*std(x2)^2));
se23 = sigma3.*sqrt(1./((length (x3)-1)*std(x3)^2));
% creating a line of best fit
X1 = [min(x1):1e-3:max(x1)]';
Y1 = k1(1,1) + k1(2,1).*X1;
X2 = [min(x2):1e-3:max(x2)]';
Y2 = k2(1,1) + k2(2,1).*X2;
X3 = [min(x3):1e-3:max(x3)]';
Y3 = k3(1,1) + k3(2,1).*X3;
SE1=sigma1.*sqrt(1/length(x1)+(X1-mean(x1)).^2./((length(x1)-1)*std(x1).^2));
Ci1=tinv(.975,length(x1)-2).*SE1;
SE2=sigma2.*sqrt(1/length(x2)+(X2-mean(x2)).^2./((length(x2)-1)*std(x2).^2));
Ci2=tinv(.975,length(x2)-2).*SE2;
SE3=sigma3.*sqrt(1/length(x3)+(X3-mean(x3)).^2./((length(x3)-1)*std(x3).^2));
Ci3=tinv(.975,length(x3)-2).*SE3;
figure(1)
clf
plot(x1, y1, 'ob')
hold on
% plotting the conidence intervals


plot (X1, Y1, 'g')
plot(X1,Y1+Ci1,'g--')
plot(X1,Y1-Ci1,'g--')
hold off
xlabel('$$\frac{1}{mg}$$','interpreter','latex')
ylabel('$$\frac{1}{l_1-l_0}$$', 'interpreter','latex')
title('Spring Constant')
print(figure(1), '-dpng', 'figure1')
figure(2)
clf
plot(x2, y2, 'ob')
hold on
% plotting the conidence intervals
plot (X2, Y2, 'R')
plot(X2,Y2+Ci2,'g--')
plot(X2,Y2-Ci2,'g--')
hold off
xlabel('$$\frac{1}{mg}$$','interpreter','latex')
ylabel('$$\frac{1}{l_1-l_0}$$','interpreter','latex')
title('Spring Constant')
print(figure(2), '-dpng', 'figure2')
figure(3)
clf
plot(x3, y3, 'ob')
hold on
% plotting the conidence intervals
plot (X3, Y3, 'y')
plot(X3,Y3+Ci3,'g--')
plot(X3,Y3-Ci3,'g--')
hold off
xlabel('$$\frac{1}{mg}$$','interpreter','latex')
ylabel('$$\frac{1}{l_1-l_0}$$','interpreter','latex')
title('Spring Constant')
print(figure(3), '-dpng', 'figure3')

Best Answer

Hi,
you are a little to precise. Your code produces an Inf for max(x1), due to your values of M1 and M2, use a value near zero for the first entry instead of zeros to avoid this:
% Measured masses of spring 1, 2 and 3 measured in meters(m).
M1=[1e-6 .1 .2 .3 .4 .5 .6 .7 .8 .9]';
M2=[1e-6 .05 .1 .15 .2 .25 .3 .35 .4 .45]';
The code takes some time to execute, but it runs without errors if you fix this and shows the figures as expected:
Best regards
Stephan
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