Can't plot this function

I'm trying to plot this:

t=linspace(0,50,50);

plot(t,5*heaviside(t - 7/10)*((9*exp(7/45 - (2.*t)./9))...
    ./11 - (20.*exp(7/100 - t./10))./11 + 1))

The error is Error using * Inner matrix dimensions must agree.

Where am I missing my dots?

Answer 1

[Star Strider]

You need to do element-wise operations, specifically replacing ‘*’ with ‘.*’, ‘/’ with ‘./’, etc. everywhere in an expression involving vectors of the same length.

See Array vs. Matrix Operations for details.

[David Chau]

Does it have to be everywhere or just where the variable matrix appears?

[Walter Roberson]

You do not need it in the case where you have a scalar constant multiplied by something, or in the case where you are dividing something by a scalar constant, or in any sub-expression that involves strictly scalar constants, such as 7/45 .

 plot(t, 5*heaviside(t - 7/10) .* ((9*exp(7/45 - (2*t)/9))/11 - (20*exp(7/100 - t/10))/11 + 1) )