Description
The IDWT2D function is the inverse of DWT2D. IDWT2D applies
inverse wavelet transforms on multiple sequences simultaneously.
IDWT2D takes as input the output tbl_teradata and meta tbl_teradata
generated by function DWT2D (td_dwt2d_mle
) and outputs the sequences as 2-dimensional
matrices. Because the IDWT2D output is comparable to the DWT2D
input, the inverse transformation is also called the reconstruction.
Usage
td_idwt2d_mle ( meta.table = NULL, coefficient = NULL, input.columns = NULL, sort.column = NULL, compact.output = TRUE, partition.columns = NULL, coefficient.sequence.column = NULL, meta.table.sequence.column = NULL )
Arguments
meta.table |
Required Argument. |
coefficient |
Required Argument. |
input.columns |
Required Argument. |
sort.column |
Required Argument. |
compact.output |
Optional Argument. |
partition.columns |
Optional Argument. |
coefficient.sequence.column |
Optional Argument. |
meta.table.sequence.column |
Optional Argument. |
Value
Function returns an object of class "td_idwt2d_mle" which is a named
list containing objects of class "tbl_teradata".
Named list members can be referenced directly with the "$" operator
using following names:
output.table
output
Examples
# Get the current context/connection con <- td_get_context()$connection # Load example data. # dataset contains climate data in cities in California (CA), Texas (TX), and Washington (WA). # The cities are represented by two-dimensional coordinates (latitude and longitude). # The data are temperature (in degrees Fahrenheit), pressure (in Mbars), # and dew point (in degrees Fahrenheit). loadExampleData("dwt2d_example", "twod_climate_data") # Create object(s) of class "tbl_teradata". twod_climate_data <- tbl(con, "twod_climate_data") # Example 1 - The function outputs a coefficient model tbl_teradata and a meta tbl_teradata. td_dwt2d_out <- td_dwt2d_mle(data = twod_climate_data, input.columns = c("temp_f","pressure_mbar","dewpoint_f"), index.columns = c("latitude","longitude"), wavelet = "db2", level = 2, compact.output = TRUE, partition.columns = c("state") ) # Consume output of td_dwt2d_mle() and output the sequences. td_idwt2d_out <- td_idwt2d_mle(meta.table = td_dwt2d_out$meta.table, coefficient = td_dwt2d_out$coefficient, input.columns = c("temp_f","pressure_mbar","dewpoint_f"), sort.column = "waveletid", partition.columns = c("state") )