# Distance Matrix

Video 1 : Generation of the Distance Matrix

# Module Description

Calculate a distance vector(matrix) between any Geographically Weigthed (GW) model calibration point(s) and the data points.

# Argument

`Focus`: an integer, indexing to the current GW model point, if focus=0, all the distances between all the GW model calibration points and data points will be calculated and a distance matrix will be returned; if 0<focus<length(number of data points), then the distances between the ’focus’th GW model points and data points will be calculated and a distance vector will be returned

`Power`: the power of the Minkowski distance,default is 2, i.e. the Euclidean distance.

Figure 1. Minkowski distance

`Theta (Angle in radians)` : an angle in radians to rotate the coordinate system, default is 0

`longlat` : if TRUE, great circle distances will be calculated

# Value

After loading data, to generate the distance matrix, you must select the appropriate arguments (focus, power, and theta, longlat) and click on the Run button.

Returns a numeric distance matrix or vector (if focus > 0); matrix with its rows corresponding to the observations and its columns corresponds to the GW model calibration points.

# References

Gollini, I., Lu, B., Charlton, M., Brunsdon, C., & Harris, P. (2015). GWmodel: An R Package for Exploring Spatial Heterogeneity Using Geographically Weighted Models. Journal of Statistical Software, 63(17), 1–50. https://doi.org/10.18637/jss.v063.i17