plot is showing blank

function shiv7

%K0= (2*pi/1530)*1e6:(2*pi/10)*1e6:(2*pi/1630)*1e6;

%K0= linspace((2*pi/1530)*1e6,(2*pi/1630)*1e6,5);

D1=linspace(1,300,10);

for j=1:numel(D1)

da = D1(j);

p0 = 1;

p1 = 1.5;

p2 = 2;

TOL = 10^-8;

N0 = 100; format long

h1 = p1 - p0;

h2 = p2 - p1;

DELTA1 = (f(p1,da) - f(p0,da ))/h1;

DELTA2 = (f(p2,da ) - f(p1,da ))/h2;

d = (DELTA2 - DELTA1)/(h2 + h1);

i=3;

while i <= N0

b = DELTA2 + h2*d;

D = (b^2 - 4*f(p2,da )*d)^(1/2);

if abs(b-D) < abs(b+D)

E = b + D;

else

E = b - D;

end

h = -2*f(p2,da)/E;

p = p2 + h;

if abs(h) < TOL

disp(p)

break

end

p0 = p1;

p1 = p2;

p2 = p;

h1 = p1 - p0;

h2 = p2 - p1;

DELTA1 = (f(p1,da ) - f(p0,da ))/h1;

DELTA2 = (f(p2,da ) - f(p1,da ))/h2;

d = (DELTA2 - DELTA1)/(h2 + h1);

i=i+1;

end

P(j)=real(p);

%R(j)=real(r);

end

plot(D1*1e-9,P)

end

function y=f(kx,da )

l=6330*(10)^(-10);

k0=2*pi/l;

nc=1.33;

ec=nc^2;

na=1.43;

ea=na^2;

nf=1.59;

ef=nf^2;

nm=0.064+1i*4;

em=nm^2;

ns=1.495;

es=ns^2;

df=0.5e-6;

dm=0.03e-6;

%da=0.06e-6;

%kx=(2*pi/l)*np*sin(a);

kc=sqrt(kx^2-ec*k0^2);

ka=sqrt(ea*k0^2-kx^2);

kf=sqrt(ef*k0^2-kx^2);

km=sqrt(em*k0^2-kx^2);

ks=sqrt(kx^2-es*k0^2);

rfm=(kf-km)/(kf+km);

rms=(km-ks)/(ks+km);

rfa=(kf-ka)/(kf+ka);

rac=(ka-kc)/(ka+kc);

a=(1-rfm)/(1+rfm);

b=(1-rms*exp(2*1i*dm*km))/(1+rms*exp(2*1i*dm*km));

c=(1-rfa)/(1+rfa);

f=(1-rac*exp(2*1i*da*ka))/(1+rac*exp(2*1i*da*ka));

pfms=2*atan(1i*a*b);

pfac=2*atan(1i*c*f);

y=2*kf*df-pfms-pfac;

end

[shiv gaur]

pl help for plot and the change in na/change in kx vs da

[Star Strider]

Please always look at the variables the code is creating and that are to be plotted —

%K0= (2*pi/1530)*1e6:(2*pi/10)*1e6:(2*pi/1630)*1e6;
 %K0= linspace((2*pi/1530)*1e6,(2*pi/1630)*1e6,5);
 D1=linspace(1,300,10);
for j=1:numel(D1)
    
    da = D1(j);
    p0 = 1;
    p1 = 1.5;
    p2 = 2;
    TOL = 10^-8;
    N0 = 100; format long
    h1 = p1 - p0;
    h2 = p2 - p1;
    DELTA1 = (f(p1,da) - f(p0,da ))/h1;
    DELTA2 = (f(p2,da ) - f(p1,da ))/h2;
    d = (DELTA2 - DELTA1)/(h2 + h1);
    i=3;
    while i <= N0 
        
        b = DELTA2 + h2*d;
        D = (b^2 - 4*f(p2,da )*d)^(1/2);
        
        if abs(b-D) < abs(b+D)
            E = b + D;
        else
            E = b - D;
        end
        
        h = -2*f(p2,da)/E;
        p = p2 + h;
        
        if abs(h) < TOL      
            disp(p) 
            break
        end
        
        p0 = p1;
        p1 = p2;
        p2 = p;
        h1 = p1 - p0;
        h2 = p2 - p1;
        DELTA1 = (f(p1,da ) - f(p0,da ))/h1;
        DELTA2 = (f(p2,da ) - f(p1,da ))/h2;
        d = (DELTA2 - DELTA1)/(h2 + h1);
        i=i+1;

    end
    
    pv(j) = p;
    P(j)=real(p);
%R(j)=real(r);
end
pv                                                  % Display 'p' Vector

pv = 
                NaN +               NaNi                NaN +               NaNi                NaN +               NaNi                NaN +               NaNi                NaN +               NaNi                NaN +               NaNi                NaN +               NaNi                NaN +               NaNi                NaN +               NaNi                NaN +               NaNi

p_stats = [nnz(isnan(pv)), numel(pv)]               % [Number Of 'NaN' Values, Length Of Vector]

p_stats = 1×2

10 10

plot(D1*1e-9,P)

function  y=f(kx,da )
   
l=6330*(10)^(-10);
   
k0=2*pi/l;
nc=1.33;
ec=nc^2;
na=1.43;
ea=na^2;
nf=1.59;
ef=nf^2;
nm=0.064+1i*4;
em=nm^2;
ns=1.495;
es=ns^2;
df=0.5e-6;
dm=0.03e-6;
%da=0.06e-6;
%kx=(2*pi/l)*np*sin(a);
kc=sqrt(kx^2-ec*k0^2);
ka=sqrt(ea*k0^2-kx^2);
kf=sqrt(ef*k0^2-kx^2);
km=sqrt(em*k0^2-kx^2);
ks=sqrt(kx^2-es*k0^2);
rfm=(kf-km)/(kf+km);
rms=(km-ks)/(ks+km);
rfa=(kf-ka)/(kf+ka);
rac=(ka-kc)/(ka+kc);
a=(1-rfm)/(1+rfm);
b=(1-rms*exp(2*1i*dm*km))/(1+rms*exp(2*1i*dm*km));
c=(1-rfa)/(1+rfa);
f=(1-rac*exp(2*1i*da*ka))/(1+rac*exp(2*1i*da*ka));
pfms=2*atan(1i*a*b);
pfac=2*atan(1i*c*f);
y=2*kf*df-pfms-pfac;
end

The ‘p’ variable consists entirely of NaN values, and NaN values cannot be plotted. You need to discover the reason for this, and correct the code.

.

Answer 1

[shiv gaur]

pl help for ploting

[shiv gaur]

graph should be like this fig

[shiv gaur]

1.graph is showing blank

2.pl plot dkx/dna=change in kx/change in na vs da value

any one pl help

Answer 2

[shiv gaur]

now it is working

function shiv7

%K0= (2*pi/1530)*1e6:(2*pi/10)*1e6:(2*pi/1630)*1e6;

%K0= linspace((2*pi/1530)*1e6,(2*pi/1630)*1e6,5);

%D1=1e-9:1e-9:3e-7;

D1= linspace(1e-9,3e-7,15);

for j=1:numel(D1)

da = D1(j);

p0 = 1;

p1 = 1.5;

p2 = 2;

TOL = 10^-8;

N0 = 100; format long

h1 = p1 - p0;

h2 = p2 - p1;

DELTA1 = (f(p1,da) - f(p0,da ))/h1;

DELTA2 = (f(p2,da ) - f(p1,da ))/h2;

d = (DELTA2 - DELTA1)/(h2 + h1);

i=3;

while i <= N0

b = DELTA2 + h2*d;

D = (b^2 - 4*f(p2,da )*d)^(1/2);

if abs(b-D) < abs(b+D)

E = b + D;

else

E = b - D;

end

h = -2*f(p2,da)/E;

p = p2 + h;

if abs(h) < TOL

disp(p)

break

end

p0 = p1;

p1 = p2;

p2 = p;

h1 = p1 - p0;

h2 = p2 - p1;

DELTA1 = (f(p1,da ) - f(p0,da ))/h1;

DELTA2 = (f(p2,da ) - f(p1,da ))/h2;

d = (DELTA2 - DELTA1)/(h2 + h1);

i=i+1;

end

%pv(j)=p;

P(j)=real(p)

%R(j)=real(r);

end

k0=2*pi/0.6328*10^-10;

plot(D1,P/k0)

end

function y=f(kx,da )

l=6330*(10)^(-10);

k0=2*pi/l;

nc=1.33;

ec=nc^2;

na=1.43;

ea=na^2;

nf=1.59;

ef=nf^2;

nm=0.064+1i*4;

em=nm^2;

ns=1.495;

es=ns^2;

df=0.5e-6;

dm=0.03e-6;

%da=0.06e-6;

%kx=(2*pi/l)*np*sin(a);

kc=sqrt(kx^2-ec*k0^2);

ka=sqrt(ea*k0^2-kx^2);

kf=sqrt(ef*k0^2-kx^2);

km=sqrt(em*k0^2-kx^2);

ks=sqrt(kx^2-es*k0^2);

rfm=(kf-km)/(kf+km);

rms=(km-ks)/(ks+km);

rfa=(kf-ka)/(kf+ka);

rac=(ka-kc)/(ka+kc);

a=(1-rfm)/(1+rfm);

b=(1-rms*exp(2*1i*dm*km))/(1+rms*exp(2*1i*dm*km));

c=(1-rfa)/(1+rfa);

f=(1-rac*exp(2*1i*da*ka))/(1+rac*exp(2*1i*da*ka));

pfms=2*atan(1i*a*b);

pfac=2*atan(1i*c*f);

y=2*kf*df-pfms-pfac;

end