How to avoid log10 from calculating for log values or if its calculated for complex log how do i avoid it?

for example if code

log10(-3) i get

ans =

0.4771 + 1.3644i

but as we know log isn't defined for negative value. My objective is to calculate the correction factor for acoustic measurement the code is as follows and the how do i avoid this function calculating the log value of negative numbers.

% when delta is in the range of [-4,4];

delta=-10:0.1:10

K_factor=-(10*log10(1-10.^(-0.1*delta)))

%SPls=10*log10(10^(SPLt/10) - 10.^(K_factor./10))

plot(delta,K_factor)

xlabel("Delta Value");

ylabel("K Factor")

Answer 1

[Stephen23]

"how do i avoid this function calculating the log value of negative numbers."

Don't call the function with negative values.

delta = -10:0.1:10;
V = 1-10.^(-0.1*delta);
X = V>0;
K_factor = nan(size(delta));
K_factor(X) = -10*log10(V(X));
plot(delta,K_factor)