calcNewField: Simple calculation of new Fields

In MagicForrest/DGVMTools: DGVM Processing, Analysis and Plotting Tools

Simple calculation of new Fields

Description

Basic calculation of new Fields by operation '+', '-', '*' or '/'

Usage

calcNewField(
  x,
  y,
  op,
  x.col = NULL,
  y.col = NULL,
  quant = NULL,
  verbose = TRUE
)

Arguments

x	The first Field
y	The second Field
op	which arithmetic should be performed: addition ('+'), substraction ('-'), multiplication ('*') or division ('/').
x.col	the column of the first Field. If empty or NULL all columns are used.
y.col	the column of the second Field. If empty or NULL all columns are used.
quant	new Quantity definition to use, if NULL it will be guessed.
verbose	print some messages.

Value

A new Field.

Author(s)

Joerg Steinkamp [e-mail]

Examples

 
# First define a Source and read a Field
test.dir <- system.file("extdata", "LPJ-GUESS_Runs", "CentralEurope", package = "DGVMTools")
test.Source <- defineSource(name = "Run 1", dir = test.dir,  format = GUESS)
test.Field <- getField(source = test.Source, quant = "lai", year.aggregate.method = "mean")
test.Source.2 <- defineSource(name = "Run 2", dir = test.dir,  format = GUESS)
test.Field.2 <- getField(source = test.Source.2, quant = "lai", year.aggregate.method = "mean")

# division, result should be 1 or NA everywhere since Fields are the same 
# (NAs come wherever the Field is zero)
test.division <- calcNewField(x=test.Field, y = test.Field.2, op = "/")
print(plotSpatial(test.division))

# subtraction, result should be 0 everywhere since Fields are the same
test.subtraction <- calcNewField(x=test.Field, y = test.Field.2, op = "-", verbose = FALSE)
print(plotSpatial(test.subtraction))

# addition, select Total only and compare to original
test.addition <- calcNewField(x=test.Field, y = test.Field.2,
                              x.col = "Total", y.col = "Total", op = "+")
print(plotSpatial(list(test.addition, test.Field), layers = "Total"))

# multiplication, select a couple of Layers only and compare to original
test.multiplication <- calcNewField(x=test.Field, y = test.Field.2, x.col = c("C3G", "TeBS"), 
                                    y.col = c("C3G", "TeBS"), op = "*", verbose = FALSE)
print(plotSpatial(list(test.multiplication, test.Field), layers =  c("C3G", "TeBS")))

MagicForrest/DGVMTools documentation built on Aug. 23, 2024, 8:05 a.m.