Gravity code

voxGrav(X::Array{Float64, 3}, Y::Array{Float64, 3}, Z::Array{Float64, 3}, RHO::Array{Float64, 3};
refMod="AVG", lengthUnit="m", rhoTol=1e-9, Topo=[], outName="Bouguer", printing=true)

Computes Bouguer anomalies and gradients  

Required arguments:  
X,Y,Z:       3D matrices with the coordinates of the grid (X should vary in the first dimension, Y in the second, Z (vertical) in the thrid)  
RHO:         3D matrix with the densitiy at each grid point [kg/m^3]  

Optional arguments:  
refMod:      1D vector with the reference density for each depth  
             Alternatively, the strings "NE", "SE", "SW", "NW", "AVG" can be used.  
             In that case, one of the corners of `RHO` is used as reference model.  
             In case of "AVG" the reference model is the average of each depth slice.  
lengthUnit:  The unit of the coordinates and topography file. Either "m" or "km"  
rhoTol:      density differences smaller than rhoTol will be ignored [kg/m^3]  
Topo:        2D matrix with the topography of the surface (only relevant for the paraview output)  
outName:     name of the paraview output (do not include file type)  
printing:    activate printing of additional information [true or false]