# Cost function This cost function is the one to be minimized using the Inverse Problem solver. It will need some information about the target and the direct problem. ```r cost(parm) ``` ## Arguments - `parm`: Set of values to be considered as parameters for the Direct Problem solution ## Returns Squared Difference between the target and the result that is calculated with the informed set of parameters 'parm'. ## Examples ```r # # Configure the name of the folder where each file with the parameter to be changed. # If the folder is 'wd' then it will not be changed. # You can change it to another location where your parameter files are. auxi <- system.file(package = "gripp") folder_name <- c(auxi,auxi) # # Configure the name of each file to be changed in the Direct Problem Solver. file_name <- c('f1.R','f1.R') # # Configure the name of each parameter to be changed. parm_name <- c('A','B') # # Configure alternative method using line number to enter each parameter # When line_number is zero, then the input method uses keywords. line_number <-c(0,0) # # Configure each parameter type, where: # 1 means a numeric variable informed as a string, such as parm <- "1.38" # 2 means a numeric vector informed as a string of numbers separated with a space character. # For example, parm <- "1.25 3.4". You must tell which one will be the variable considered. parm_type <- c(1,1) # # Informe the position of the variable to be considered in the problem in the vector. # If the parameter is a numeric variable, then its position is zero. parm_vector <- c(0,0) # # Configure the name of the folder where the command must be called. # If the folder is 'wd' then it will not be changed. # You can change it to another location where your parameter files are. command_folder <- auxi # # This variable means that the Direct Problem is solved using R or outside # if this is FALSE, the results are to be read from a file. # When it is TRUE, results will be passed inside R using the variable "results" isitR <- TRUE # # Configure the command to be used to call the Direct Problem Solver. command <- 'f1.R' # # Configure the name of the file to be used as a target by the cost function. # The file was built using parm <- c(1,3). # It is also a single column of values. target <- 'alvo.dat' # # Configure the name of the folder where the target file can be found. # If the folder is 'wd' then it will not be changed. # You can change it to another location where your target file is. target_folder <- auxi # # Configure a string to be used to attrib values in the Direct Problem file. attrib_str <- '<-' # # Configure the name of the file with the results obtained by the Direct Problem. # It must be a single column of values. # The results are changed at each run by the Direct Problem Solver. result <- 'result.dat' # # Configure the name of the folder where the results can be found after each run. # If the folder is 'wd' then it will not be changed. # You can change it to another location where your result file is. result_folder <- tempdir() # parm<- c(1,3) cost(parm) parm<- c(1.5,4) cost(parm) ```