optimize_bend.RdOptimize the elastic_modulus, the shear_modulus or both using observations.
optimize_bend( field_data, elastic_modulus = c(1, 10000), shear_modulus = c(1, 10000), type = c("all", "bending", "torsion"), method = "L-BFGS-B", tol = .Machine$double.eps^0.25, nb_rep = 5, ... )
| field_data | data.frame, or list of data.frames with the x, y and z coordinates of the observed points. If list of data.frames, each element correspond to a separate beam (e.g. each branch) |
|---|---|
| elastic_modulus | Elasticity modulus (bending, MPa). See details. |
| shear_modulus | Shear modulus (torsion, MPa). See details. |
| type | Type of optimization (either "bending","torsion" or "all") |
| method | Method to use when optimizing one parameter (see |
| tol | Tolerance for optimization accuracy |
| nb_rep | Number of starting points for the optimization algorithm |
| ... | Further parameters to pass to |
A list of the outputs:
The best optimized values for each parameter
init_values: a data.frame with the initial values used for each repetition
optim_values: a data.frame with the optimized values for each step
min_quadratic_error: minimum quadratic error of all repetitions
rep_min_crit: index of the repetition that gave the minimum quadratic error
plots: plots of optimal value ~ initial value for each parameter to analyze
the sensitivity of the optimized value to the starting points.
The elastic_modulus and shear_modulus are either provided as a vector of min and max values if optimized, or as a single value to force the parameter if not optimized.
file_path = system.file("extdata/6_EW01.22_17_kanan.txt", package = "biomech") field_data = read_mat(file_path) # optimize_bend(field_data, type = "all") # Gives: # $elastic_modulus # [1] 1209.622 # $shear_modulus # [1] 67.49158 # $init_values # elastic_modulus shear_modulus # 1 8154.915 110.9907 # 2 7070.047 4120.5218 # 3 9580.339 5798.9579 # 4 2980.401 4703.5510 # 5 8860.528 545.3304 # $optim_values # [,1] [,2] # [1,] 1209.316 67.35572 # [2,] 1209.598 67.27172 # [3,] 1214.884 8091.98399 # [4,] 1209.622 67.49158 # [5,] 1223.161 2126.35615 # $min_quadratic_error # [1] 0.3787925 # $rep_min_crit # [1] 4 # $plots # $plots[[1]] # Here comes a ggplot for the first parameter # $plots[[2]] # Here comes a ggplot for the second parameter # If only the elastic_modulus is optimized, the shear_modulus has to be fixed: # optimize_bend(field_data, shear_modulus = 100, type = "bending") # If the parameters need to be optimized on several beams at the same time (they share # the same properties), pass their observations as a list: # optimize_bend(list(sim1 = field_data, sim2 = field_data), type = "all")