how to remove some portion of boundary of an object without affecting remaining portion in matlab by programming

i have one query. i made a 2-d figure 'c.png' in matlab by using r and theta and with the help of boundary function..now i want to make a figure 'p.png' from previous figure..i made it manually but i want to make it automatically by programming ..i attached figures in png format due to size is very large in fig format..please help me

[KSSV]

YOu have the data of green points shown in the figures?

[VANDANA GUPTA]

yes...(f1,f2)

Answer 1

[KSSV]

load f1.mat ; 
load f2.mat ; 

x = f1 ; y = f2 ; 

figure
hold on
plot(x,y,'*r')
idx = x>35.5 ; 

x(idx) = [] ;
y(idx) = [] ; 

plot(x,y,'Og')

[VANDANA GUPTA]

thanx a lot sir.. it works..sir , i also want to join the front surface..boundary function joins the back points also which i dont want..

[KSSV]

Put NaN at the end point for x and y.

[VANDANA GUPTA]

THANK YOU VERY MUCH SIR...I AM VERY GRATEFUL TO YOU..