# What is the delta parameter in $\tt scal2freq$?

I am running complex morlet (cmor1-1.5) wavelet transform. I want to have the transformation for the range of $[1,150]\textrm{ Hz}$ with a step of $1\textrm{ Hz}$. I want to use scal2freq Matlab function to convert scales to pseudo frequencies but I don`'t know how to define the delta.