misvm_orova {mildsvm} | R Documentation |
Fit MI-SVM model to ordinal outcome data using One-vs-All
Description
This function uses the one-vs-all multiclass classification strategy to fit a series of MI-SVM models for predictions on ordinal outcome data. For an ordinal outcome with K levels, we fit K MI-SVM models to predict an individual level vs not.
Usage
## Default S3 method:
misvm_orova(
x,
y,
bags,
cost = 1,
method = c("heuristic", "mip", "qp-heuristic"),
weights = TRUE,
control = list(kernel = "linear", sigma = if (is.vector(x)) 1 else 1/ncol(x),
nystrom_args = list(m = nrow(x), r = nrow(x), sampling = "random"), max_step = 500,
type = "C-classification", scale = TRUE, verbose = FALSE, time_limit = 60, start =
FALSE),
...
)
## S3 method for class 'formula'
misvm_orova(formula, data, ...)
## S3 method for class 'mi_df'
misvm_orova(x, ...)
Arguments
x |
A data.frame, matrix, or similar object of covariates, where each
row represents an instance. If a |
y |
A numeric, character, or factor vector of bag labels for each
instance. Must satisfy |
bags |
A vector specifying which instance belongs to each bag. Can be a string, numeric, of factor. |
cost |
The cost parameter in SVM. If |
method |
The algorithm to use in fitting (default |
weights |
named vector, or |
control |
list of additional parameters passed to the method that control computation with the following components:
|
... |
Arguments passed to or from other methods. |
formula |
a formula with specification |
data |
If |
Value
An object of class misvm_orova
The object contains at least the
following components:
-
fits
: a list ofmisvm
objects with length equal to the number of classes iny
. Seemisvm()
for details on themisvm
object. -
call_type
: A character indicating which methodmisvm_orova()
was called with. -
features
: The names of features used in training. -
levels
: The levels ofy
that are recorded for future prediction.
Methods (by class)
-
default
: Method for data.frame-like objects -
formula
: Method for passing formula -
mi_df
: Method formi_df
objects, automatically handling bag names, labels, and all covariates.
Author(s)
Sean Kent
References
Andrews, S., Tsochantaridis, I., & Hofmann, T. (2002). Support vector machines for multiple-instance learning. Advances in neural information processing systems, 15.
See Also
predict.misvm_orova()
for prediction on new data.
Examples
data("ordmvnorm")
x <- ordmvnorm[, 3:7]
y <- ordmvnorm$bag_label
bags <- ordmvnorm$bag_name
mdl1 <- misvm_orova(x, y, bags)
predict(mdl1, x, new_bags = bags)