Variable output as "1x0 empty double row vector" halfway through the program after previous iterations in the for loop has normal output values for the same variables.

Why am I getting 1x0 empty double row vectors for the last several iterations of the variables Peaks and X_Peak_value? The output seems to produce values for these variables up to a point and then the output only displays "1x0 empty double row vector".

Here is my code...

clear all;clc
Data = InputData('CJ1');

Unrecognized function or variable 'InputData'.

for i = 1:1:90
    for x = 1:1:900
        vel = 0;
        vel = vel + 1*x;
        alt = 0;
        alt = alt + 500*i;
        R = aerodynamics(vel, alt,Data);
        V(x) = vel;
        RC(x) = R.RC;
    end
    [Peaks, X_Peak_value] = findpeaks(RC, V)
    ROC_max(i)= Peaks;
    Vel_max_ROC(i) = X_Peak_value;
end
plot(Vel_max_ROC, ROC_max)

Answer 1

[Cris LaPierre]

We can't run your code to explore why specifically, but my guess is that they are empty because findpeaks did not identify any peaks in your input RC.

Answer 2

[Torsten]

It may happen that no peaks can be found:

RC = 1:4;
V = 1:4;
[Peaks, X_Peak_value] = findpeaks(RC, V)

Peaks =

  1×0 empty double row vector


X_Peak_value =

  1×0 empty double row vector