6. Declustering and trend analysis

6.1 Distance betwen samples (download)

Compute distances between all pairs of samples and plot distances in a cumulative histogram.

Variables to customize

- varcolXY <- c(1,2) # index of the GTD frame X and Y coordinates

- sizePOINTS <- 1  # size of the sample symbols of the left plot
- titleGRAPH # global title of the left plot

6.2 Compute Vononoi Polygons (download)

Compute Voronoi polygons and compute declustered basic statistics. An histogram of the Voronoi polygon areas are displayed at right.

Variables to customize:  

- varcolXY <- c(1,2) # index of the GTD frame X and Y coordinates
- varlistindex <- c(5,6,7,8,9,10,11) # index of the GTD frame Qualitative Variables to recompute declustered basic statistics
- titleGRAPH <- "Representação em planta das amostras de solos" # global title of the left plot
- ndecimals <- 3 # number of decimal places

6.3 Cell declustering (download)

Overlap a set of samples with a mesh of cells and compute average values of several variables within each cell. After, compute global declustered basic statistics.

Variables to customize:  

- varcolXY <- c(1,2) # index of the GTD frame X and Y coordinates
- varlistindex <- c(5,6,7,8,9,10,11) # index of the GTD frame Qualitative Variables to recompute declustered basic statistics
- titleGRAPH <- "Localizações das amostras" # global title of the left plot
- ndecimals <- 3 # number of decimal places
- cellsizex=250 # size of the cells in X direction
- cellsizey=250 # size of the cells in Y direction

6.4 Spatial trend analysis in X and Y directions (download)

Perform a trend analysis of a quantitative variable along X and Y directions.

Variables to customize:  

- varcolXY <- c(1,2) # index of the GTD frame X and Y coordinates

- varlistindex <- 10 # index of the GTD quantitative variable to trend analysis
- ndecimals <- 3 # number of decimal places
- cellsizex=150 # size of the cells in X direction
- cellsizey=150 # size of the cells in Y direction
- sizePOINTS # size of the symbols to plot