Help i get this error: Array indices must be positive integers or logical values. Error in simulering (line 35) plot(v(t),t)

clear all;
close all;
clc;

load('GaugeDataPart01.mat','INTtimeSERIE')
load('gaugeData.mat','event_summary')
%konstanter
t=INTtimeSERIE(:,1);
I=INTtimeSERIE(:,2);
Fred=5.70492; %Ha
Qud=1*Fred; %l/s/Ha
alpha=0.76; 
c=28070;
f=1;

 v=@(t) Fred*(f*c*t.^-(0.76).*t-Qud*t);

 
 v=@(t) v(t-1)+f*I*Fred-Qud;


if v(t)>=0
    v(t)=v(t-1)+f*I*Fred-Qud;

else
    v=0;
end
    

plot(v(t),t)
datetick('x','mm-yy')
xlabel('dato')
ylabel('volumen [m^3]')

Answer 1

[KALYAN ACHARJYA]

plot(v,t)

[Magnus Poulsen]

Now when i display the values, its all the same...