X and Y matrix of size:1x68.this code works well.but when command " plot(X,Y,'ro', x,y,'-b',xt,yt,'--g');" shifted outside for loop; plot for last value of xt and yt How to store all values of xt and yt outside for loop?

 Value of X=[272  273  274  275  276  277  278  279  280  281  282  283  284  285  286  287  288  289  290  291  292  293  294  295  296  297  298  299  300  301  302  303  304  305  306  307  308  309  310  311  312  313  314  315  316  317  318  319  320  321  322  323  324  325  326  327  328  329  330  331  332  333  334  335  336  337  338  339
] 
and Value of Y=[310  310  310  310  310  310  310  310  310  310  310  311  311  311  311  310  309  310  311  313  313  314  314  314  314  313  314  313  314  314  314  314  314  314  314  315  315  315  315  313  315  316  316  315  315  315  316  316  316  316  316  316  316  316  315  315  315  316  317  317  317  318  319  318  319  319  319  320
]
if true
   X0data = X;
 for i=1:length(X0data)
     X0 = X0data(i);

     Y = x9';
      n = 1000; % 100 or some higher number for nice curves
 f = 0.1; % this defines the length of the tangent
x = linspace(min(X),max(X),n); 
y = interp1(X,Y,x,'spline'); 
xt = X0+(0.1*(max(X)-min(X))*[-1 0 1]);
m = diff(y)./diff(x);
m = [m, m(end)]; % so just add one at the end
k = min([find(x >= X0,1,'first'), length(x)]);

yt = y(k) + m(k)*(0.1*(max(X)-min(X))*[-1 0 1]);

     plot(X,Y,'ro', x,y,'-b',xt,yt,'--g');
     hold on;  % to allow multiple plots on same figure
 end % code
  end

Answer 1

[Mahdi]

Change the the lines to:

xt(i,:) = X0+(0.1*(max(X)-min(X))*[-1 0 1]);

and

yt(i,:) = y(k) + m(k)*(0.1*(max(X)-min(X))*[-1 0 1]);

[vaishali]

 not plotting tangent components.

[Mahdi]

Change the xt and yt in the plot function to xt(i,:) and yt(i,:)

[vaishali]

It results error msg: Index exceeds matrix dimensions.