A positive vector representing distances (often in km)
a
Positive number (usually between 0 and 1) representing
the intercept of the distance decay curve with the y axis, when x = 0.
b1
Number representing the 'beta' distance decay parameter.
Higher values make the decay steeper.
b2
Number representing the second 'beta' distance decay parameter.
Higher values make the decay steeper.
log-linear distance decay (Iacono et al., 2010) with an additional
square-root term to make the curve more flexible. The additional
term (b2 in the func
References
Iacono, M., Krizek, K. J. and El-Geneidy, A. (2010).
Measuring non-motorized accessibility: issues, alternatives, and execution. Journal of Transport Geography, 18(1).