varmer: Variational merging
In VARMER: Variational Merging

Description Usage Arguments Value Examples

Apply a function to the interpolated and satellite image (These image are raster, see raster). The function is based on many functions, these are applied in the following order:

img2varmer Compare two raster or bricks with different z values(uhat and v images) It check if the images has the same extension, resolution, coordinate reference system, columns and rows.

pre_data Using a variable in the needed format the unique coordinates. The function calculates necessary variables for mesh_3.

mesh_3 The function mesh_3 takes as input data the length of the domain in x (Lx), the length of the domain in y (Ly), the number of divisions in x (Nx) and the number of divisions in y (Ny). These values are obtained with the function prev_data, specifically from coordinates inside the variable uhat (which must be equal to those of v).

var_merge It takes as input the coordinates of the nodes (variable coordinates defined in the mesh_3 function). The table of elements (variable elements defined in the mesh_3 function). The fields uhat and v, and the factor eta_0.

plot_mesh Using the data of previous functions (mesh_3 and var_merge), three 3D graphs are realized. Each graph represent in order the variation through the space (longitude and latitude) U,uhat and v.

varmer(
  uhat.img,
  v.img,
  eta_0,
  color_plot = grDevices::heat.colors,
  create_plots = F
)

`uhat.img`	The interpolated image as a raster.
`v.img`	The satellite image as a raster.
`eta_0`	A scalar
`color_plot`	The name of a palette of color from grDevices
`create_plots`	Flag defining whether plots are to be created

Three 3D plots corresponding to the variation of U, uhat and v in the space. A list containing initial data, preparation data and U. Inside of U there are two files U_varmer is a data frame and U_img a raster.

library(raster)
data(uhat_raster,"VARMER")
force(uhat.raster)
data(v_raster,"VARMER")
force(v.raster)
eta_0=0.5
color_plot=topo.colors
varmer_results=varmer(uhat.raster,v.raster,eta_0,color_plot)