Vector error when using plot function

Hello, I am trying to plot the following and keep receiving an eror on plot((V1:0.1:Vmax),nmax) stating:

Error using plot - Vectors must be the same length.

Error in maybeFinal (line 285)

plot((V1:0:Vmax),nmax)

this is my code, would someone be able to help me please :

nmax = 3.8;

nmin = -1.5;

V1=((nmax*2*W)/(C_Lmax*rho1*S))^(1/2);

V2=((nmin*2*W)/(C_Lmax*rho1*S))^(1/2);

Vpos=[0:V1];

Vneg=[0:V2];

q = 30.42;

n1=(C_Lmax*rho1*S*Vpos.^2)/(2*W);

n2=(C_Lmax*rho1*S*Vneg.^2)/(2*W);

Vmax=((2*q)/rho1)^(1/2);

% Plotting Vn diagram %

plot(Vpos, n1)

hold on

plot(Vneg, n2)

hold on

plot((V1:0.1:Vmax),nmax)

hold on

plot([V2:.1:Vmax],nmin)

hold on

plot(Vmax,[nmin:.01:nmax])

% Labeling Vn Diagram %

gtext ('Positive Stall Limit')

gtext ('Negative Stall Limit')

gtext ('Positive Structural Limit')

gtext ('Negative Structural Limit')

xlabel ('Calibrated Airspeed, ft/sec')

ylabel ('Load Factor, n')

Answer 1

[Star Strider]

This:

plot((V1:0:Vmax),nmax)

creates an empty vector for the independent variable vector, since there is an increment (or step) of 0.

I suspect that you intended to replicate this plot call:

plot((V1:0.1:Vmax),nmax)

instead.

[Bharkha Mistry]

Thank you!

I used the correction that you provided and still receive the same error.

[Star Strider]

My pleasure!

Try something like this:

Vvct = linspace(V1, Vmax, numel(nmax));

This assumes ‘nmax’ is a vector.

If it is a matrix, choose the dimension (rows=1 or columns=2) that you want as the independent variable, and change it to:

Vvct = linspace(V1, Vmax, size(nmax,1));

for example, with this plotting across the columns as a function of the rows. The plot function automatically uses the other dimension as the independent variable, if they are different. With a square matrix, it may be necessary to transpose it to get the correct plot.