what this equation means 4*L/(2*i-1)?

I am trying to convert this equation 4*L/(2*i-1) into R

I failed to undersatnd why the output is two negative values in matlab

but R'output is a single value

L= 17;

i=4;

(2*i-1) gives -1 + 2; Is it i here is a complex number?

[Walter Roberson]

format long g
L = 17;
4*L/(2*i-1)

ans = 
                      -13.6 -                  27.2i

Notice the second number has the i after it. That i indices a complex component.

4*L/(2*sqrt(-1)-1)

ans = 
                      -13.6 -                  27.2i

[Torsten]

If you use the expression 4*L/(2*i-1) in R, I guess that "i" was set to a value somewhere before in the R-code. If you set "i" to the same value in your MATLB code, MATLAB will compute the same value for the expression as R does. If you don't set "i" to a value before you compute the expression, MATLAB will interprete "i" as the imaginary unit.

L = 17;
i = 4;
4*L/(2*i-1)

ans = 9.7143

clear i
4*L/(2*i-1)

ans = -13.6000 -27.2000i

[Alexander]

Never use i or j if you are not dealing with complex numbers. Use ii or jj instead if you have to.

Answer 1

[ScottB]

Yes, Matlab sees "i" as complex. Maybe pick another variable if you are just using scalars.