Plotting two functions that depend on boundary conditions.

I have two functions,

V_lamp_off(t)=Vs+(Voff-Vs)*y and V_lamp_on(t)=Vth+(Von-Vth)*exp(z). I want to plot V_lamp_off when the value is between 1 and 4 and plot V_lamp_on when the value is between 4 and 1. The length of the plot is driven by t. I can plot the two functions individually but want to show the shark tooth wave form. I've tried an if/then sequence with no luck.

if V_lamp_off <= Voff 
      then a = V_lamp_off;  
elseif V_lamp_off >= Von
       then a = V_lamp_on;
elseif V_lamp_on <= Voff
        then a =V_lamp_off;
        end
 
plot (t,a)

Any help would be appreciated.

[madhan ravi]

upload your full code with the required datas

Answer 1

[madhan ravi]

"I want to plot V_lamp_off when the value is between 1 and 4 and plot "

Which value do you mean?

Instead of

if V_lamp_off <= Voff 
      then a = V_lamp_off;  
elseif V_lamp_off >= Von
      then a = V_lamp_on;
elseif V_lamp_on <= Voff
      then a =V_lamp_off;
end
plot (t,a)

should be

a=ones(1,numel(t))
idx=(V_lamp_off <= Voff )
a(idx)=V_lamp_off(idx)
iddx=(V_lamp_off >= Von)
a(idx)=V_lamp_on(idx)
plot(t,a)

[madhan ravi]

Anytime :)

Answer 2

[SnukeN3]

clc, clear
%ECE 203-001 Team Project
format compact
 
% Part 2
Vs=6;
Von=4;
Voff=1;
t=0:0.001:40;
Rlamp=2.0E4;
R=2.32E5;
C=47E-6;
T=R*C;
x=-t/T;
y=exp(x);
 
V_lamp_off=Vs+(Voff-Vs)*y
 
% Part 3
 
Vth=Vs*(Rlamp/(R+Rlamp));
t0=R*C*log10((Voff-Vs)\(Von-Vs));
tc=t0+R*C*log10((Von-Vth)\(Voff-Vth));
z=-t/T;
V_lamp_on=Vth+(Von-Vth)*exp(z)
 
%Visualization
 
if V_lamp_off <= Voff 
      then a = V_lamp_off;  
elseif V_lamp_off >= Von
       then a = V_lamp_on;
elseif V_lamp_on <= Voff
        then a =V_lamp_off;
        end
 
plot (t,a)

Answer 3

[SnukeN3]

Closer, I think. The output wave from should have a log rising edge and an exponential falling edge, kind of a cool repeating shark fin. I'm getting a matrix full of ones and nothing on the graph

Answer 4

[SnukeN3]

Made a small change and I'm very close to the desired out put. I'll check my math. Thanks!

a=ones(size(t));

idx=(V_lamp_off <= Von )

a(idx)=V_lamp_off(idx )

idx=(V_lamp_on >= Von )

a(idx)=V_lamp_on(idx )

plot(t,a)