Extend only two lines on a plot

I made a plot on Matlab with three experimental data lines and two theoretical. I need to extend only the two theoretical (Vturb and Vlam) to the top of the plot. Everything I've tried has not worked so any ideas would be much appreciated.

%140%
DP140= [0.200 0.192 0.182 0.170 0.162 0.151 0.138 0.132 0.130 0.122 0.117 0.108 0.102 0.087 0.076];
DPlb140=DP140*5.20;
V140=((2*DPlb140)/0.00238).^(1/2);
VCL140 = V140/29.5626;

%60 Hz%
DP60 = [0.043 0.045 0.042 0.040 0.038 0.037 0.035 0.032 0.031 0.031 0.027 0.026 0.024 0.021 0.018];
DPlb60=DP60*5.20;
V60=((2*DPlb60)/0.00238).^(1/2);
VCL60 = V60/13.7076;

%100 Hz%
DP100 = [0.123 0.118 0.112 0.108 0.103 0.095 0.089 0.085 0.081 0.078 0.075 0.065 0.062 0.057 0.042];
DPlb100=DP100*5.20;
V100=((2*DPlb100)/0.00238).^(1/2);
r = [0 2 4 6 8 10 12 14 16 18 20 22 24 26 28]/304.8;
R = 0.125;
rR = r/R;
VCL100 = V100/23.1836;

Vlam = (1-rR.^2);
Vturb = (1-rR).^(1/7);

plot(VCL140, rR)
hold on 
plot(VCL60, rR)
plot(VCL100, rR)
plot(Vturb,rR)
plot(Vlam,rR)

ylabel("r/R")
xlabel("V/Vcl")
title("Velocites vs. Distance")
legend("Meas V140","Meas V60","Meas V100", "Laminar", "Turbulent")
hold off

Answer 1

[Star Strider]

One option is to extrapolate the two curves.

That then changes these lines:

plot(Vturb,rR)

plot(Vlam,rR)

to these modified lines:

yl = ylim;

Vte = interp1(rR, Vturb, yl(2), 'pchip', 'extrap');

Vle = interp1(rR, Vlam, yl(2), 'pchip', 'extrap');

plot([Vturb Vte],[rR yl(2)])

plot([Vlam Vle],[rR yl(2)])

with this result —

%140%
DP140= [0.200 0.192 0.182 0.170 0.162 0.151 0.138 0.132 0.130 0.122 0.117 0.108 0.102 0.087 0.076];
DPlb140=DP140*5.20;
V140=((2*DPlb140)/0.00238).^(1/2);
VCL140 = V140/29.5626;

%60 Hz%
DP60 = [0.043 0.045 0.042 0.040 0.038 0.037 0.035 0.032 0.031 0.031 0.027 0.026 0.024 0.021 0.018];
DPlb60=DP60*5.20;
V60=((2*DPlb60)/0.00238).^(1/2);
VCL60 = V60/13.7076;

%100 Hz%
DP100 = [0.123 0.118 0.112 0.108 0.103 0.095 0.089 0.085 0.081 0.078 0.075 0.065 0.062 0.057 0.042];
DPlb100=DP100*5.20;
V100=((2*DPlb100)/0.00238).^(1/2);
r = [0 2 4 6 8 10 12 14 16 18 20 22 24 26 28]/304.8;
R = 0.125;
rR = r/R;
VCL100 = V100/23.1836;

Vlam = (1-rR.^2);
Vturb = (1-rR).^(1/7);

figure
plot(VCL140, rR)
hold on 
plot(VCL60, rR)
plot(VCL100, rR)
yl = ylim;
Vte = interp1(rR, Vturb, yl(2), 'pchip', 'extrap');
Vle = interp1(rR, Vlam, yl(2), 'pchip', 'extrap');
plot([Vturb Vte],[rR yl(2)])
plot([Vlam Vle],[rR yl(2)])
ylabel("r/R")
xlabel("V/Vcl")
title("Velocites vs. Distance")
legend("Meas V140","Meas V60","Meas V100", "Laminar", "Turbulent")
hold off

The other option is to set:

ylim([min(ylim) max(rR)]

That re-positions the upper value of ylim to the highest value of ‘rR’.

It all depends on what you want to do.

.

[Jolie Gaffron]

THANK YOU!! You have no idea how long I've been messing with this.

[Star Strider]

As always, my pleasure!