How to round a decimal to 4 digits

angle = Phi_intrp(ismembertol(round(s1*10^4)/10^4,s2));

So I am given a table Phi_intrp, which I can evaluate at every entry of s1.

s1 = transpose(-27:0.0001:2)

so it is a very large array. I want to evaluate Phi_intrp at every entry of s2, however. s2 contains measurement data, decimals with 4 digits after the dot. All entries of s2 are within the range of s1. So I figured, when I round the entries of s1 to 4 digits after the dot, I should be able to use the code line mentioned at first to evaluate Phi_intrp at the desired values. It is not working, however. And the

round(s1*10^4)/10^4

does not round the entries to 4 digits after the dot either.

What am I doing wrong?

Answer 1

[Image Analyst]

Pass 4 into round():

>> r=rand
r =
         0.383306318625529
>> r4 = round(r, 4)
r4 =
                    0.3833

Answer 2

[Walter Roberson]

ismembertol(A, B, 1e-4,'Datascale',1)