Simplifying code for plot.

How simplify my code to where I can write t=[0 .2 .5 1 2] instead of writing them individually as t1,t2 etc... And possibly plot it as just plot(x,y) to where I get the same graph. Below is the code I am referring to.

clear
t0=0
t1=.2
t2=.5
t3=1
t4=2
x=-6:12/100:6
y0=-2*sinh(x)./(cosh(x)-exp(-t0));
y1=-2*sinh(x)./(cosh(x)-exp(-t1));
y2=-2*sinh(x)./(cosh(x)-exp(-t2));
y3=-2*sinh(x)./(cosh(x)-exp(-t3));
y4=-2*sinh(x)./(cosh(x)-exp(-t4));

plot(x,y0,'--')
hold on
plot(x,y1)
plot(x,y2) 
plot(x,y3)
plot(x,y4)

axis([-6 6 -4 4])

Answer 1

[Star Strider]

This works:

tv = [0 .2 .5 1 2];
x = -6:12/100:6;
for k1 = 1:length(tv)
    y(k1,:) = -2*sinh(x)./(cosh(x)-exp(-tv(k1)));
end

figure(1)
plot(x, y)
grid
axis([xlim    -4  4])
legend('t = 0.0', 't = 0.2', 't = 0.5', 't = 1.0', 't = 2.0')

With a ‘t’ vector of only 5 elements, it’s easier to to just use a loop and some straightforward coding. With a longer vector, other approaches (using bsxfun and parsing the legend entries) would be more efficient.

Answer 2

[dpb]

Simplest is probably to write the function as anonymous function then just loop over the t0 values building the array--

 fy=@(x,t0) -2*sinh(x)./(cosh(x)-exp(-t0));    % anonymous function in x,t0
 y=zeros(length(x),length(t));                 % preallocate for output
 for i=1:length(t),y(:,i)=fy(x.',t(i));end     % evaluate function of t array
 figure
 hL=plot(x,y);                                 % plot, save line handles
 xlim([-6 6]),ylim([-4 4])

NB: when called the function made sure that x was column vector so output of fy would also be columnar. plot and friends presume that is the orientation of variables when y is an array. Fix up the line properties as desired using the line handles returned from plot. >>