the graph is empty, how can i solve this,(there are lot of constant values)

clc;
clear all;
close all;
syms q1 q2 q3 q4 qt1 qt2 qt3 qt4 m1 m2 m3 m4 l1 l2 l3 l4 h1 h2 h3 h4 g x
syms I1 I2 I3 I4  Q1 Q2 Q3 Q4 qtt1 qtt2 qtt3 qtt4 t real 

l1=270*10^-3;
l2=230*10^-3;
l3=198*10^-3;
l4=50*10^-3;  
g=9.80665;
m1=23.687;
m2=17.15;
m3=2.0125;
m4=0.4179;
h1=765*10^-3;
h2=568*10^-3;
h3=418*10^-3;
h4=220*10^-3;
I1=0.099379;
I2=0.050526;
I4=0.000405;
I3=0.000702;
k1=(1/3)*(m1*l1^2*qt1^2);
k2=0.5*m2*((qt1^2*l1^2)+(0.25*qt2^2*l2^2)+(qt1*qt2*l1*l2*cos(q2)))+(0.5*I2*qt1);
k3=0.5*m3*((qt1^2*l1^2)+(qt3^2*l2^2)+(2*qt1*qt3*l1*l2*((qt1^2)+(qt1*qt2))*cos(q2)))+(0.5*I1*qt1^2)+(0.5*I2*(qt1+qt2)^2);
k4=(0.5*m4*l4^2*qt4^2);
p1=m1*g*h1;
p2=m2*g*(h1-h2);
p3=m3*g*(h1-h2-(0.5*q3));
p4=m4*g*(h1-h2-q3-(h4*0.5));
k=k1+k2+k3+k4;
p=p1+p2+p3+p4;
L=k-p;

for  x=0:1:10
  q1=3-(3*cos(pi*x/10));
  qt1=3*sin(pi*x/10)*pi/10;
  qtt1=3*cos(pi*x/10)*(pi^2/100);
  q2=3-(3*sin(pi*x/10));
  qt2= -3*cos(pi*x/10)*(pi/10);
  qtt2=3*sin(pi*x/10)*(pi^2/100);
  qt3=0.198*x^2;
  qtt3=0.198*x;
  qtt4=sin(x)+cos(x);
  Lqt1 =I2/2 + I1*qt1 + (m2*(2*qt1*l1^2 + l2*qt2*cos(q2)*l1))/2 + (m3*(2*l1^2*qt1 + 2*l1*l2*qt3*cos(q2)*(qt1^2 + qt2*qt1) + 2*l1*l2*qt1*qt3*cos(q2)*(2*qt1 + qt2)))/2 + (I2*(2*qt1 + 2*qt2))/2 + (2*l1^2*m1*qt1)/3;
  Lqt2 =(m2*((qt2*l2^2)/2 + l1*qt1*cos(q2)*l2))/2 + (I2*(2*qt1 + 2*qt2))/2 + l1*l2*m3*qt1^2*qt3*cos(q2) ;
  Lqt3 = (m3*(2*l2^2*qt3 + 2*l1*l2*qt1*cos(q2)*(qt1^2 + qt2*qt1)))/2;
  Lqt4 = l4^2*m4*qt4;
  Lq1 = 0;
  Lq2 = - (l1*l2*m2*qt1*qt2*sin(q2))/2 -( l1*l2*m3*qt1*qt3*sin(q2)*(qt1^2 + qt2*qt1));
  Lq3 =(g*m3)/2 + g*m4;
  Lq4 = 0;
  Ldt1 =qtt2*(I2 + (l1*l2*m2*cos(q2))/2 + 2*l1*l2*m3*qt1*qt3*cos(q2)) + qtt1*(I1 + I2 + (m3*(2*l1^2 + 4*l1*l2*qt3*cos(q2)*(2*qt1 + qt2) + 4*l1*l2*qt1*qt3*cos(q2)))/2 + (2*l1^2*m1)/3 + l1^2*m2) - qt2*((m3*(2*l1*l2*qt3*sin(q2)*(qt1^2 + qt2*qt1) + 2*l1*l2*qt1*qt3*sin(q2)*(2*qt1 + qt2)))/2 + (l1*l2*m2*qt2*sin(q2))/2) + (m3*qtt3*(2*l1*l2*cos(q2)*(qt1^2 + qt2*qt1) + 2*l1*l2*qt1*cos(q2)*(2*qt1 + qt2)))/2;
  Ldt2 =qtt2*((m2*l2^2)/4 + I2) + qtt1*(I2 + (l1*l2*m2*cos(q2))/2 + 2*l1*l2*m3*qt1*qt3*cos(q2)) - qt2*(l1*l2*m3*qt3*sin(q2)*qt1^2 + (l1*l2*m2*sin(q2)*qt1)/2) + l1*l2*m3*qt1^2*qtt3*cos(q2);
  Ldt3 =l2^2*m3*qtt3 + (m3*qtt1*(2*l1*l2*cos(q2)*(qt1^2 + qt2*qt1) + 2*l1*l2*qt1*cos(q2)*(2*qt1 + qt2)))/2 + l1*l2*m3*qt1^2*qtt2*cos(q2) - l1*l2*m3*qt1*qt2*sin(q2)*(qt1^2 + qt2*qt1);
  Ldt4 =l4^2*m4*qtt4;
  Q1 = Ldt1 - Lq1
  % Q2 = Ldt2 - Lq2
  % Q3 = Ldt3 - Lq3
  % Q4 = Ldt4 - Lq4
  plot(x,Q1)
  hold on
  end

[John D'Errico]

Solve what? You probably have a bug in your code. We have been given no clue as to what it is supposed to do. So how do we know where you did something wrong? The crystal ball is so foggy.

Learn to step through your code. ONE line at a time. Check everything. Does what came out make sense? If not, then stop there, either fix it, or understand what happened.

Only you can fix a mess of completely undocumented code that you wrote.

[paripavithran sampathu]

i got the answer what i required , but i could not get the graph as continuous line

[Walter Roberson]

Well, we aren't going to be able to help you further without a copy of your code.

[Rena Berman]

(Answers Dev) Restored Question.

Answer 1

[Walter Roberson]

You are using plot() with scalar x and scalar Q1, rather than vectors, so you are drawing a bunch of points, not a line. The default for plot() is to use no marker, so the points you draw are all invisible. You need to add a marker specification to the plot() call, or else you need to record the x values and the Q1 values as you go through the loop instead of plotting, then after the loop plot() them all at one time to get a line.