Question: Exporting plot data

Ok I dont think I provided enough data last I asked this and as a result I am still stuck so here goes;

I have data in 4 matrices describing a wave going from one medium to another, the incident wave transmission and reflection coefficients (F1), the exiting waves transmittance and reflection coefficients (F2) and the propagating waves in each medium (P1 and P2). All this boils down to 4 matrices with data.

The propagating wave and incident wave vectors are summed and square rooted and the Real parts defined as cos_phi[i] for increasing k which the 4 matrices before are defined by.

I plotted the results as cos_bloch_phase1 using pointplot and the sequence of values of k versus cos_phi.

Then displayed cos_bloch_phase1,plot... etc

What I am struggling to figure out is how to export the data that is plotted in cos_bloch_phase1. I have copied and pasted my code in its entirety of which a further plot is included but can be ignored as they are constructed similarly;

restart;
with(plots): with(linalg):

matrix elements for the first interface

incident parameters
theta0:=89*Pi/180; k_min:=0.0; k_max:=25;

number_of_points:=1000;
step:=(k_max-k_min)/number_of_points;
                              1000
                         0.02500000000

parameters of a binary crystal
n1:=1.46; n2:=4.6; d1:=0.1; d2:=0.1;
                              1.46
                              4.6
                              0.1
                              0.1


for i from 0 by 1 to number_of_points do
k[i]:=k_min+i*step;

theta1:=evalf(arcsin(n0*sin(theta0)/n1)); theta2:=evalf(arcsin(n0*sin(theta0)/n2));
q1:=k[i]*n1*cos(theta1); q2:=k[i]*n2*cos(theta2);


F1:=Matrix([[(q1+q2)/(2*q1),(q1-q2)/(2*q1)],[(q1-q2)/(2*q1),(q1+q2)/(2*q1)]]);
F2:=Matrix([[(q2+q1)/(2*q2),(q2-q1)/(2*q2)],[(q2-q1)/(2*q2),(q2+q1)/(2*q2)]]);
P1:=Matrix([[exp(-I*q1*d1),0],[0,exp(I*q1*d1)]]);
P2:=Matrix([[exp(-I*q2*d2),0],[0,exp(I*q2*d2)]]);
M_period:=multiply(P1, F1, P2, F2);

cos_phi[i]:=Re(1/2*(M_period[1,1]+M_period[2,2]));
end:


cos_bloch_phase1:=pointplot([seq([k[i],cos_phi[i]],i=0..number_of_points)],connect=true):

display(cos_bloch_phase1,plot([1,-1],x=0..k_max,color=[red,red]));



for i from 0 by 1 to number_of_points do
k[i]:=k_min+i*step;

theta1:=evalf(arcsin(n0*sin(theta0)/n1)); theta2:=evalf(arcsin(n0*sin(theta0)/n2));
q1:=k[i]*n1*cos(theta1); q2:=k[i]*n2*cos(theta2);

F1p:=Matrix([[(q1/n1^2+q2/n2^2)/(2*q1/n1^2),(q1/n1^2-q2/n2^2)/(2*q1/n1^2)],[(q1/n1^2-q2/n2^2)/(2*q1/n1^2),(q1/n1^2+q2/n2^2)/(2*q1/n1^2)]]);
F2p:=Matrix([[(q2/n2^2+q1/n1^2)/(2*q2/n2^2),(q2/n2^2-q1/n1^2)/(2*q2/n2^2)],[(q2/n2^2-q1/n1^2)/(2*q2/n2^2),(q2/n2^2+q1/n1^2)/(2*q2/n2^2)]]);
P1p:=Matrix([[exp(-I*q1*d1),0],[0,exp(I*q1*d1)]]);
P2p:=Matrix([[exp(-I*q2*d2),0],[0,exp(I*q2*d2)]]);
Mp_period:=multiply(P1p, F1p, P2p, F2p);


cos_phi2[i]:=Re(1/2*(Mp_period[1,1]+Mp_period[2,2]));
end:



cos_bloch_phase2:=pointplot([seq([k[i],cos_phi2[i]],i=0..number_of_points)],connect=true):

display(cos_bloch_phase2,plot([1,-1],x=0..k_max,color=[red,red]));


display(cos_bloch_phase2,cos_bloch_phase1,plot([1,-1],x=0..k_max+5,color=[red,red]));