clc
close all
clear all
a=0;
m=10;
b=15;
xmin=0;
xmax=15;

it=1;
for x=xmin:0.1:xmax
    if x<=a
        v(it)=1
    elseif a<=x<=m
        v(it)=(x-a)/(m-a)
    elseif x==m
        v(it)=1
    elseif m<=x<=b
        v(it)=(b-x)/(b-m)
    elseif x>=b
        v(it)=b
    end
end
s=linspace(xmin,xmax,(xmin+xmax)*10)
plot(s,v,'--')