Interpolate points to contours using a Generalized Additive Model (GAM)

Fit generalized additive model to a variable in space using a smoother on latitude & longitude. Further clip by bounding polygon.

pts_to_contours_gam(df, ply, gam_k = 60, grid_width = 0.1, n_breaks = 7)

Arguments

df: data frame containing the fields: lon (longitude), lat (latitude) and v (value)
ply: polygon describing the study area mask
gam_k: number of knots to use on the spatial smoother s(lon, lat); default: 100
grid_width: cell width in decimal degrees to run interpolation; default: 0.1
n_breaks: number of breaks in values for creating contours; default: 7

polygon simple features (sf) of contour isoband::isobands()

v_ply <- pts_to_contours_gam(bottle_temp_lonlat, area_calcofi_extended)
mapview::mapView(v_ply, zcol="v", layer.name="temp(C)")