What does the following MATLAB code do?

>> x=7.123456789;
>> n=7;
>> delta=0.5;
>> r=x*10^n+delta;
>> r=fix(r);
>> r=r/10^n;
>> disp(r)

Answer 1

[Star Strider]

It takes ‘x’, raises it to the ‘n’-th power, adds ‘delta’ to it, then rounds that result toward zero, divides that result by ‘10^n’ and prints the result.

The intent appears to be to round ‘x’ to 7 decimal places.

You can do that easily with the current version of the round function:

r = round(x, 7)

that will produce the same result.

[Walter Roberson]

I noticed that it does not do the same thing as round(x,n) for negative numbers.

>> fix(-pi*100000+0.5)/100000
ans =
                  -3.14158
>> round(-pi,5)
ans =
                  -3.14159