Error while integrating a piecewise constant function

I defined a function

>> temp = [2;1.5; 0.75; 1.5; 3.75; 0.75; 1.25; .075; 2.0; 1.0; 1.0];

>> A1 = @(x) temp(floor(x*10)+1);

it's a single input single output function. I want to integrate A1(x) from 0 to 1. When I use Matlab's numerical integrator integral. It throws the following error:

>> integral(A1,0,1)

Error using integralCalc/finalInputChecks (line 526)

Output of the function must be the same size as the

input. If FUN is an array-valued integrand, set the

'ArrayValued' option to true.

Just to check if the integral isn't working how it is supposed to be, I defined a dummy function

>> f = @(x) sin(x)

I am able to integrate it properly. I am not sure what's the problem with the function A1(x). I am using Matlab R2018a

Answer 1

[madhan ravi]

integral(A1,0,1,'ArrayValued',1)

Answer 2

[John D'Errico]

As an alternative to that which Madhan shows, you can make sure the result is of the correct shape.

A1 = @(x) reshape(temp(floor(x*10)+1),size(x));
integral(A1,0,1)
ans =
       1.4575

Either way will work. What matters most is to read the error message, and then fix the problem that integral tripped over.