Title: | Cluster-Based Permutation Analysis for Densely Sampled Time Data |
---|---|
Description: | An implementation of fast cluster-based permutation analysis (CPA) for densely-sampled time data developed in Maris & Oostenveld, 2007 <doi:10.1016/j.jneumeth.2007.03.024>. Supports (generalized, mixed-effects) regression models for the calculation of timewise statistics. Provides both a wholesale and a piecemeal interface to the CPA procedure with an emphasis on interpretability and diagnostics. Integrates 'Julia' libraries 'MixedModels.jl' and 'GLM.jl' for performance improvements, with additional functionalities for interfacing with 'Julia' from 'R' powered by the 'JuliaConnectoR' package. |
Authors: | June Choe [aut, cre, cph] |
Maintainer: | June Choe <[email protected]> |
License: | MIT + file LICENSE |
Version: | 1.1.4 |
Built: | 2024-11-10 18:21:25 UTC |
Source: | https://github.com/yjunechoe/jlmerclusterperm |
Calculate bootstrapped p-values of cluster-mass statistics
calculate_clusters_pvalues( empirical_clusters, null_cluster_dists, add1 = FALSE ) clusters_are_comparable(empirical_clusters, null_cluster_dists, error = FALSE)
calculate_clusters_pvalues( empirical_clusters, null_cluster_dists, add1 = FALSE ) clusters_are_comparable(empirical_clusters, null_cluster_dists, error = FALSE)
empirical_clusters |
A |
null_cluster_dists |
A |
add1 |
Whether to add 1 to the numerator and denominator when calculating the p-value.
Use |
error |
Whether to throw an error if incompatible |
An empirical_clusters
object augmented with p-values.
extract_empirical_clusters()
, extract_null_cluster_dists()
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Make empirical clusters empirical_statistics <- compute_timewise_statistics(spec) empirical_clusters <- extract_empirical_clusters(empirical_statistics, threshold = 2) empirical_clusters # Make null cluster-mass distribution reset_rng_state() null_statistics <- permute_timewise_statistics(spec, nsim = 100) null_cluster_dists <- extract_null_cluster_dists(null_statistics, threshold = 2) # Significance test the empirical cluster(s) from each predictor against the simulated null calculate_clusters_pvalues(empirical_clusters, null_cluster_dists) # Set `add1 = TRUE` to normalize by adding 1 to numerator and denominator calculate_clusters_pvalues(empirical_clusters, null_cluster_dists, add1 = TRUE) # This sequence of procedures is equivalent to `clusterpermute()` reset_rng_state() clusterpermute(spec, threshold = 2, nsim = 100, progress = FALSE) # The empirical clusters and the null cluster-mass distribution must be comparable empirical_clusters2 <- extract_empirical_clusters(empirical_statistics, threshold = 3) # For example, below code errors because thresholds are different (2 vs. 3) try( calculate_clusters_pvalues(empirical_clusters2, null_cluster_dists) ) # Check for compatibility with `clusters_are_comparable()` clusters_are_comparable(empirical_clusters, null_cluster_dists) clusters_are_comparable(empirical_clusters2, null_cluster_dists)
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Make empirical clusters empirical_statistics <- compute_timewise_statistics(spec) empirical_clusters <- extract_empirical_clusters(empirical_statistics, threshold = 2) empirical_clusters # Make null cluster-mass distribution reset_rng_state() null_statistics <- permute_timewise_statistics(spec, nsim = 100) null_cluster_dists <- extract_null_cluster_dists(null_statistics, threshold = 2) # Significance test the empirical cluster(s) from each predictor against the simulated null calculate_clusters_pvalues(empirical_clusters, null_cluster_dists) # Set `add1 = TRUE` to normalize by adding 1 to numerator and denominator calculate_clusters_pvalues(empirical_clusters, null_cluster_dists, add1 = TRUE) # This sequence of procedures is equivalent to `clusterpermute()` reset_rng_state() clusterpermute(spec, threshold = 2, nsim = 100, progress = FALSE) # The empirical clusters and the null cluster-mass distribution must be comparable empirical_clusters2 <- extract_empirical_clusters(empirical_statistics, threshold = 3) # For example, below code errors because thresholds are different (2 vs. 3) try( calculate_clusters_pvalues(empirical_clusters2, null_cluster_dists) ) # Check for compatibility with `clusters_are_comparable()` clusters_are_comparable(empirical_clusters, null_cluster_dists) clusters_are_comparable(empirical_clusters2, null_cluster_dists)
Tidiers for cluster permutation test objects
## S3 method for class 'timewise_statistics' tidy(x, ...) ## S3 method for class 'empirical_clusters' tidy(x, ...) ## S3 method for class 'null_cluster_dists' tidy(x, ...)
## S3 method for class 'timewise_statistics' tidy(x, ...) ## S3 method for class 'empirical_clusters' tidy(x, ...) ## S3 method for class 'null_cluster_dists' tidy(x, ...)
x |
An object of class |
... |
Unused |
A data frame
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Method for `<timewise_statistics>` empirical_statistics <- compute_timewise_statistics(spec) class(empirical_statistics) tidy(empirical_statistics) reset_rng_state() null_statistics <- permute_timewise_statistics(spec, nsim = 100) class(null_statistics) tidy(null_statistics) # Method for `<empirical_clusters>` empirical_clusters <- extract_empirical_clusters(empirical_statistics, threshold = 2) class(empirical_clusters) tidy(empirical_clusters) # Method for `<null_cluster_dists>` null_cluster_dists <- extract_null_cluster_dists(null_statistics, threshold = 2) class(null_cluster_dists) tidy(null_cluster_dists)
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Method for `<timewise_statistics>` empirical_statistics <- compute_timewise_statistics(spec) class(empirical_statistics) tidy(empirical_statistics) reset_rng_state() null_statistics <- permute_timewise_statistics(spec, nsim = 100) class(null_statistics) tidy(null_statistics) # Method for `<empirical_clusters>` empirical_clusters <- extract_empirical_clusters(empirical_statistics, threshold = 2) class(empirical_clusters) tidy(empirical_clusters) # Method for `<null_cluster_dists>` null_cluster_dists <- extract_null_cluster_dists(null_statistics, threshold = 2) class(null_cluster_dists) tidy(null_cluster_dists)
Conduct a cluster-based permutation test
clusterpermute( jlmer_spec, family = c("gaussian", "binomial"), statistic = c("t", "chisq"), threshold, nsim = 100L, predictors = NULL, binned = FALSE, top_n = Inf, add1 = TRUE, ..., progress = TRUE )
clusterpermute( jlmer_spec, family = c("gaussian", "binomial"), statistic = c("t", "chisq"), threshold, nsim = 100L, predictors = NULL, binned = FALSE, top_n = Inf, add1 = TRUE, ..., progress = TRUE )
jlmer_spec |
Data prepped for jlmer from |
family |
A GLM family. Currently supports "gaussian" and "binomial". |
statistic |
Test statistic for calculating cluster mass.
Can be one of |
threshold |
The threshold value that the statistic must pass to contribute to cluster mass. Interpretation differs on the choice of statistic (more below):
|
nsim |
Number of simulations description |
predictors |
(Optional) a subset of predictors to test. Defaults to |
binned |
Whether the data has been aggregated/collapsed into time bins. Defaults to |
top_n |
How many clusters to return, in the order of the size of the cluster-mass statistic.
Defaults to |
add1 |
Whether to add 1 to the numerator and denominator when calculating the p-value.
Use |
... |
Optional arguments passed to Julia for model fitting.
Defaults to |
progress |
Defaults to |
A list of null_cluster_dists
and empirical_clusters
with p-values
compute_timewise_statistics()
, permute_timewise_statistics()
,
extract_empirical_clusters()
, extract_null_cluster_dists()
,
calculate_clusters_pvalues()
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Should minimally provide `threshold` and `nsim`, in addition to the spec object reset_rng_state() CPA <- clusterpermute(spec, threshold = 2, nsim = 100, progress = FALSE) CPA # CPA is a list of `<null_cluster_dists>` and `<empirical_clusters>` objects sapply(CPA, class) # You can extract the individual components for further inspection CPA$null_cluster_dists CPA$empirical_clusters
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Should minimally provide `threshold` and `nsim`, in addition to the spec object reset_rng_state() CPA <- clusterpermute(spec, threshold = 2, nsim = 100, progress = FALSE) CPA # CPA is a list of `<null_cluster_dists>` and `<empirical_clusters>` objects sapply(CPA, class) # You can extract the individual components for further inspection CPA$null_cluster_dists CPA$empirical_clusters
Fit Julia regression models to each time point of a time series data
compute_timewise_statistics( jlmer_spec, family = c("gaussian", "binomial"), statistic = c("t", "chisq"), ... )
compute_timewise_statistics( jlmer_spec, family = c("gaussian", "binomial"), statistic = c("t", "chisq"), ... )
jlmer_spec |
Data prepped for jlmer from |
family |
A GLM family. Currently supports "gaussian" and "binomial". |
statistic |
Test statistic for calculating cluster mass.
Can be one of |
... |
Optional arguments passed to Julia for model fitting.
Defaults to |
A predictor-by-time matrix of cluster statistics, of class timewise_statistics
.
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Predictor x Time matrix of t-statistics from regression output empirical_statistics <- compute_timewise_statistics(spec) round(empirical_statistics, 2) # Collect as dataframe with `tidy()` empirical_statistics_df <- tidy(empirical_statistics) empirical_statistics_df # Timewise statistics are from regression models fitted to each time point # - Note the identical statistics at `Time == 0` empirical_statistics_df %>% filter(time == 0) to_jlmer(weight ~ 1 + Diet, filter(ChickWeight, Time == 0)) %>% tidy() %>% select(term, statistic)
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Predictor x Time matrix of t-statistics from regression output empirical_statistics <- compute_timewise_statistics(spec) round(empirical_statistics, 2) # Collect as dataframe with `tidy()` empirical_statistics_df <- tidy(empirical_statistics) empirical_statistics_df # Timewise statistics are from regression models fitted to each time point # - Note the identical statistics at `Time == 0` empirical_statistics_df %>% filter(time == 0) to_jlmer(weight ~ 1 + Diet, filter(ChickWeight, Time == 0)) %>% tidy() %>% select(term, statistic)
Detect largest clusters from a time sequence of predictor statistics
extract_empirical_clusters( empirical_statistics, threshold, binned = FALSE, top_n = Inf )
extract_empirical_clusters( empirical_statistics, threshold, binned = FALSE, top_n = Inf )
empirical_statistics |
A predictor-by-time matrix of empirical timewise statistics. |
threshold |
The threshold value that the statistic must pass to contribute to cluster mass. Interpretation differs on the choice of statistic (more below):
|
binned |
Whether the data has been aggregated/collapsed into time bins. Defaults to |
top_n |
How many clusters to return, in the order of the size of the cluster-mass statistic.
Defaults to |
An empirical_clusters
object.
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Empirical clusters are derived from the timewise statistics empirical_statistics <- compute_timewise_statistics(spec) empirical_clusters <- extract_empirical_clusters(empirical_statistics, threshold = 2) empirical_clusters # Collect as dataframe with `tidy()` empirical_clusters_df <- tidy(empirical_clusters) empirical_clusters_df # Changing the `threshold` value identifies different clusters extract_empirical_clusters(empirical_statistics, threshold = 1) # A predictor can have zero or multiple clusters associated with it extract_empirical_clusters(empirical_statistics, threshold = 3)
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Empirical clusters are derived from the timewise statistics empirical_statistics <- compute_timewise_statistics(spec) empirical_clusters <- extract_empirical_clusters(empirical_statistics, threshold = 2) empirical_clusters # Collect as dataframe with `tidy()` empirical_clusters_df <- tidy(empirical_clusters) empirical_clusters_df # Changing the `threshold` value identifies different clusters extract_empirical_clusters(empirical_statistics, threshold = 1) # A predictor can have zero or multiple clusters associated with it extract_empirical_clusters(empirical_statistics, threshold = 3)
Construct a null distribution of cluster-mass statistics
extract_null_cluster_dists(null_statistics, threshold, binned = FALSE)
extract_null_cluster_dists(null_statistics, threshold, binned = FALSE)
null_statistics |
A simulation-by-time-by-predictor 3D array of null (permuted) timewise statistics. |
threshold |
The threshold value that the statistic must pass to contribute to cluster mass. Interpretation differs on the choice of statistic (more below):
|
binned |
Whether the data has been aggregated/collapsed into time bins. Defaults to |
A null_cluster_dists
object.
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Null cluster-mass distributions are derived from the permuted timewise statistics reset_rng_state() null_statistics <- permute_timewise_statistics(spec, nsim = 100) null_cluster_dists <- extract_null_cluster_dists(null_statistics, threshold = 2) null_cluster_dists # Collect as dataframe with `tidy()` # - Each simulation contributes one (largest) cluster-mass statistic to the null # - When no clusters are found, the `sum_statistic` value is zero null_cluster_dists_df <- tidy(null_cluster_dists) null_cluster_dists_df # Changing the `threshold` value changes the shape of the null extract_null_cluster_dists(null_statistics, threshold = 1) extract_null_cluster_dists(null_statistics, threshold = 3)
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Null cluster-mass distributions are derived from the permuted timewise statistics reset_rng_state() null_statistics <- permute_timewise_statistics(spec, nsim = 100) null_cluster_dists <- extract_null_cluster_dists(null_statistics, threshold = 2) null_cluster_dists # Collect as dataframe with `tidy()` # - Each simulation contributes one (largest) cluster-mass statistic to the null # - When no clusters are found, the `sum_statistic` value is zero null_cluster_dists_df <- tidy(null_cluster_dists) null_cluster_dists_df # Changing the `threshold` value changes the shape of the null extract_null_cluster_dists(null_statistics, threshold = 1) extract_null_cluster_dists(null_statistics, threshold = 3)
Fit a Julia regression model using jlmer specifications
jlmer(jlmer_spec, family = c("gaussian", "binomial"), ..., progress = FALSE)
jlmer(jlmer_spec, family = c("gaussian", "binomial"), ..., progress = FALSE)
jlmer_spec |
Data prepped for jlmer from |
family |
A GLM family. Currently supports "gaussian" and "binomial". |
... |
Optional arguments passed to Julia for model fitting. |
progress |
If |
A jlmer_mod
object.
# Fitting a regression model with a specification object spec <- make_jlmer_spec(weight ~ 1 + Diet, ChickWeight) jlmer(spec) # `lm()` equivalent summary(lm(weight ~ 1 + Diet, ChickWeight))$coef
# Fitting a regression model with a specification object spec <- make_jlmer_spec(weight ~ 1 + Diet, ChickWeight) jlmer(spec) # `lm()` equivalent summary(lm(weight ~ 1 + Diet, ChickWeight))$coef
Initial setup for the jlmerclusterperm package
jlmerclusterperm_setup(..., cache_dir = NULL, restart = TRUE, verbose = TRUE)
jlmerclusterperm_setup(..., cache_dir = NULL, restart = TRUE, verbose = TRUE)
... |
Ignored. |
cache_dir |
The location to write out package cache files (namely, Manifest.toml).
If |
restart |
Whether to set up a fresh Julia session, given that one is already running.
If |
verbose |
Whether to print progress and messages from Julia in the console |
TRUE
options("jlmerclusterperm.nthreads" = 2) jlmerclusterperm_setup(cache_dir = tempdir(), verbose = FALSE)
options("jlmerclusterperm.nthreads" = 2) jlmerclusterperm_setup(cache_dir = tempdir(), verbose = FALSE)
Tidier methods for Julia regression models
## S3 method for class 'jlmer_mod' tidy(x, effects = c("var_model", "ran_pars", "fixed"), ...) ## S3 method for class 'jlmer_mod' glance(x, ...)
## S3 method for class 'jlmer_mod' tidy(x, effects = c("var_model", "ran_pars", "fixed"), ...) ## S3 method for class 'jlmer_mod' glance(x, ...)
x |
An object of class |
effects |
One of "var_model", "ran_pars", or "fixed" |
... |
Unused |
A data frame
# Fixed-effects only model mod1 <- to_jlmer(weight ~ 1 + Diet, ChickWeight) tidy(mod1) glance(mod1) # Mixed model mod2 <- to_jlmer(weight ~ 1 + Diet + (1 | Chick), ChickWeight) tidy(mod2) glance(mod2) # Select which of fixed/random effects to return tidy(mod2, effects = "fixed") tidy(mod2, effects = "ran_pars")
# Fixed-effects only model mod1 <- to_jlmer(weight ~ 1 + Diet, ChickWeight) tidy(mod1) glance(mod1) # Mixed model mod2 <- to_jlmer(weight ~ 1 + Diet + (1 | Chick), ChickWeight) tidy(mod2) glance(mod2) # Select which of fixed/random effects to return tidy(mod2, effects = "fixed") tidy(mod2, effects = "ran_pars")
Set/get options for Julia progress bar
julia_progress(show, width)
julia_progress(show, width)
show |
Whether to show the progress bar. You may also pass in a list of |
width |
Width of the progress bar. If |
Previous values for show
and width
# Show current progress options julia_progress() # Set options and save previous options old_progress_opts <- julia_progress(show = FALSE, width = 100) julia_progress() # Restoring progress settings by passing a list of old options old_progress_opts julia_progress(old_progress_opts) identical(julia_progress(), old_progress_opts) # Alternatively, reset to default settings using this syntax: julia_progress(show = TRUE, width = "auto")
# Show current progress options julia_progress() # Set options and save previous options old_progress_opts <- julia_progress(show = FALSE, width = 100) julia_progress() # Restoring progress settings by passing a list of old options old_progress_opts julia_progress(old_progress_opts) identical(julia_progress(), old_progress_opts) # Alternatively, reset to default settings using this syntax: julia_progress(show = TRUE, width = "auto")
Interface to the Julia RNG
set_rng_state(i) reset_rng_state() get_rng_state() set_rng_seed(seed) get_rng_seed()
set_rng_state(i) reset_rng_state() get_rng_state() set_rng_seed(seed) get_rng_seed()
i |
Counter number |
seed |
Seed |
The current seed or counter
# RNG initializes to seed=1 counter=0 get_rng_seed() get_rng_state() # setter/getter for RNG counter set_rng_state(123) get_rng_state() # setter/getter for RNG seed set_rng_seed(2) get_rng_seed() # restore to initial setting (seed=1, counter=0) set_rng_seed(1) set_rng_state(0)
# RNG initializes to seed=1 counter=0 get_rng_seed() get_rng_state() # setter/getter for RNG counter set_rng_state(123) get_rng_state() # setter/getter for RNG seed set_rng_seed(2) get_rng_seed() # restore to initial setting (seed=1, counter=0) set_rng_seed(1) set_rng_state(0)
Check Julia requirements for jlmerclusterperm
julia_setup_ok()
julia_setup_ok()
Boolean
julia_setup_ok()
julia_setup_ok()
Create a specifications object for fitting regression models in Julia
make_jlmer_spec( formula, data, subject = NULL, trial = NULL, time = NULL, drop_terms = NULL, ... )
make_jlmer_spec( formula, data, subject = NULL, trial = NULL, time = NULL, drop_terms = NULL, ... )
formula |
Model formula in R syntax |
data |
A data frame |
subject |
Column for subjects in the data. |
trial |
Column for trials in the data. Must uniquely identify a time series within subject (for example, the column for items in a counterbalanced design where each subject sees exactly one item). |
time |
Column for time in the data. |
drop_terms |
(Optional) any terms to drop from the reconstructed model formula |
... |
Unused, for extensibility. |
An object of class jlmer_spec
.
# Bare specification object (minimal spec for fitting a global model) spec <- make_jlmer_spec(weight ~ 1 + Diet, ChickWeight) spec # Constraints on specification for CPA: # 1) The combination of `subject`, `trial`, and `time` must uniquely identify rows in the data # 2) `time` must have constant sampling rate (i.e., evenly spaced values) spec_wrong <- make_jlmer_spec( weight ~ 1 + Diet, ChickWeight, time = "Time" ) unique(ChickWeight$Time) # Corrected specification for the above spec_correct <- make_jlmer_spec( weight ~ 1 + Diet, subset(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec_correct
# Bare specification object (minimal spec for fitting a global model) spec <- make_jlmer_spec(weight ~ 1 + Diet, ChickWeight) spec # Constraints on specification for CPA: # 1) The combination of `subject`, `trial`, and `time` must uniquely identify rows in the data # 2) `time` must have constant sampling rate (i.e., evenly spaced values) spec_wrong <- make_jlmer_spec( weight ~ 1 + Diet, ChickWeight, time = "Time" ) unique(ChickWeight$Time) # Corrected specification for the above spec_correct <- make_jlmer_spec( weight ~ 1 + Diet, subset(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec_correct
Permute data while respecting grouping structure(s) of observations
permute_by_predictor( jlmer_spec, predictors, predictor_type = c("guess", "between_participant", "within_participant"), n = 1L )
permute_by_predictor( jlmer_spec, predictors, predictor_type = c("guess", "between_participant", "within_participant"), n = 1L )
jlmer_spec |
Data prepped for jlmer from |
predictors |
A vector of terms from the model. If multiple, the must form the levels of one predictor. |
predictor_type |
Whether the predictor is |
n |
Number of permuted samples of the data to generate. Defaults to |
A long dataframe of permuted re-samples with .id
column representing replication IDs.
# Example data setup chickweights_df <- ChickWeight chickweights_df <- chickweights_df[chickweights_df$Time <= 20, ] chickweights_df$DietInt <- as.integer(chickweights_df$Diet) head(chickweights_df) # Example 1: Spec object using the continuous `DietInt` predictor chickweights_spec1 <- make_jlmer_spec( formula = weight ~ 1 + DietInt, data = chickweights_df, subject = "Chick", time = "Time" ) chickweights_spec1 # Shuffling `DietInt` values guesses `predictor_type = "between_participant"` reset_rng_state() spec1_perm1 <- permute_by_predictor(chickweights_spec1, predictors = "DietInt") # This calls the same shuffling algorithm for CPA in Julia, so counter is incremented get_rng_state() # Shuffling under shared RNG state reproduces the same permutation of the data reset_rng_state() spec1_perm2 <- permute_by_predictor(chickweights_spec1, predictors = "DietInt") identical(spec1_perm1, spec1_perm2) # Example 2: Spec object using the multilevel `Diet` predictor chickweights_spec2 <- make_jlmer_spec( formula = weight ~ 1 + Diet, data = chickweights_df, subject = "Chick", time = "Time" ) chickweights_spec2 # Levels of a category are automatically shuffled together reset_rng_state() spec2_perm1 <- permute_by_predictor(chickweights_spec2, predictors = "Diet2") reset_rng_state() spec2_perm2 <- permute_by_predictor(chickweights_spec2, predictors = c("Diet2", "Diet3", "Diet4")) identical(spec2_perm1, spec2_perm2)
# Example data setup chickweights_df <- ChickWeight chickweights_df <- chickweights_df[chickweights_df$Time <= 20, ] chickweights_df$DietInt <- as.integer(chickweights_df$Diet) head(chickweights_df) # Example 1: Spec object using the continuous `DietInt` predictor chickweights_spec1 <- make_jlmer_spec( formula = weight ~ 1 + DietInt, data = chickweights_df, subject = "Chick", time = "Time" ) chickweights_spec1 # Shuffling `DietInt` values guesses `predictor_type = "between_participant"` reset_rng_state() spec1_perm1 <- permute_by_predictor(chickweights_spec1, predictors = "DietInt") # This calls the same shuffling algorithm for CPA in Julia, so counter is incremented get_rng_state() # Shuffling under shared RNG state reproduces the same permutation of the data reset_rng_state() spec1_perm2 <- permute_by_predictor(chickweights_spec1, predictors = "DietInt") identical(spec1_perm1, spec1_perm2) # Example 2: Spec object using the multilevel `Diet` predictor chickweights_spec2 <- make_jlmer_spec( formula = weight ~ 1 + Diet, data = chickweights_df, subject = "Chick", time = "Time" ) chickweights_spec2 # Levels of a category are automatically shuffled together reset_rng_state() spec2_perm1 <- permute_by_predictor(chickweights_spec2, predictors = "Diet2") reset_rng_state() spec2_perm2 <- permute_by_predictor(chickweights_spec2, predictors = c("Diet2", "Diet3", "Diet4")) identical(spec2_perm1, spec2_perm2)
Simulate cluster-mass statistics via bootstrapped permutations
permute_timewise_statistics( jlmer_spec, family = c("gaussian", "binomial"), statistic = c("t", "chisq"), nsim = 100L, predictors = NULL, ... )
permute_timewise_statistics( jlmer_spec, family = c("gaussian", "binomial"), statistic = c("t", "chisq"), nsim = 100L, predictors = NULL, ... )
jlmer_spec |
Data prepped for jlmer from |
family |
A GLM family. Currently supports "gaussian" and "binomial". |
statistic |
Test statistic for calculating cluster mass.
Can be one of |
nsim |
Number of simulations description |
predictors |
(Optional) a subset of predictors to test. Defaults to |
... |
Optional arguments passed to Julia for model fitting.
Defaults to |
A simulation-by-time-by-predictor 3D array of cluster statistics, of class timewise_statistics
.
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Simulation x Time x Predictor array of t-statistics from regression output reset_rng_state() null_statistics <- permute_timewise_statistics(spec, nsim = 3) round(null_statistics, 2) # Collect as dataframe with `tidy()` permuted_timewise_stats_df <- tidy(null_statistics) permuted_timewise_stats_df # Permutations ran under the same RNG state are identical reset_rng_state() null_statistics2 <- permute_timewise_statistics(spec, nsim = 3) identical(null_statistics, null_statistics2) get_rng_state() null_statistics3 <- permute_timewise_statistics(spec, nsim = 3) identical(null_statistics, null_statistics3)
library(dplyr, warn.conflicts = FALSE) # Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, filter(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Simulation x Time x Predictor array of t-statistics from regression output reset_rng_state() null_statistics <- permute_timewise_statistics(spec, nsim = 3) round(null_statistics, 2) # Collect as dataframe with `tidy()` permuted_timewise_stats_df <- tidy(null_statistics) permuted_timewise_stats_df # Permutations ran under the same RNG state are identical reset_rng_state() null_statistics2 <- permute_timewise_statistics(spec, nsim = 3) identical(null_statistics, null_statistics2) get_rng_state() null_statistics3 <- permute_timewise_statistics(spec, nsim = 3) identical(null_statistics, null_statistics3)
Fit a Julia regression model using lme4 syntax
to_jlmer( formula, data, family = c("gaussian", "binomial"), jlmer_spec_opts = list(), ..., progress = FALSE )
to_jlmer( formula, data, family = c("gaussian", "binomial"), jlmer_spec_opts = list(), ..., progress = FALSE )
formula |
Model formula in R syntax |
data |
A data frame |
family |
A GLM family. Currently supports "gaussian" and "binomial". |
jlmer_spec_opts |
List of options passed to |
... |
Optional arguments passed to Julia for model fitting. |
progress |
If |
A jlmer_mod
object.
# Fitting a regression model with R formula syntax to_jlmer(weight ~ 1 + Diet, ChickWeight) # `lm()` equivalent summary(lm(weight ~ 1 + Diet, ChickWeight))$coef # Fitting a mixed model with {lme4} syntax to_jlmer(weight ~ 1 + Diet + (1 | Chick), ChickWeight) # Passing MixedModels.jl fit options to the `...` to_jlmer(weight ~ 1 + Diet + (1 | Chick), ChickWeight, REML = TRUE)
# Fitting a regression model with R formula syntax to_jlmer(weight ~ 1 + Diet, ChickWeight) # `lm()` equivalent summary(lm(weight ~ 1 + Diet, ChickWeight))$coef # Fitting a mixed model with {lme4} syntax to_jlmer(weight ~ 1 + Diet + (1 | Chick), ChickWeight) # Passing MixedModels.jl fit options to the `...` to_jlmer(weight ~ 1 + Diet + (1 | Chick), ChickWeight, REML = TRUE)
Test the probability of cluster-mass statistics over a range of threshold values
walk_threshold_steps( empirical_statistics, null_statistics, steps, top_n = Inf, binned = FALSE, add1 = TRUE, progress = TRUE )
walk_threshold_steps( empirical_statistics, null_statistics, steps, top_n = Inf, binned = FALSE, add1 = TRUE, progress = TRUE )
empirical_statistics |
A predictor-by-time matrix of empirical timewise statistics. |
null_statistics |
A simulation-by-time-by-predictor 3D array of null (permuted) timewise statistics. |
steps |
A vector of threshold values to test |
top_n |
How many clusters to return, in the order of the size of the cluster-mass statistic.
Defaults to |
binned |
Whether the data has been aggregated/collapsed into time bins. Defaults to |
add1 |
Whether to add 1 to the numerator and denominator when calculating the p-value.
Use |
progress |
Whether to display a progress bar |
A data frame of predictor clusters-mass statistics by threshold.
# Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, subset(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Compute timewise statistics for the observed and permuted data empirical_statistics <- compute_timewise_statistics(spec) null_statistics <- permute_timewise_statistics(spec, nsim = 100) # Test cluster mass/probability under different threshold values walk_threshold_steps(empirical_statistics, null_statistics, steps = 1:3, progress = FALSE)
# Specification object spec <- make_jlmer_spec( weight ~ 1 + Diet, subset(ChickWeight, Time <= 20), subject = "Chick", time = "Time" ) spec # Compute timewise statistics for the observed and permuted data empirical_statistics <- compute_timewise_statistics(spec) null_statistics <- permute_timewise_statistics(spec, nsim = 100) # Test cluster mass/probability under different threshold values walk_threshold_steps(empirical_statistics, null_statistics, steps = 1:3, progress = FALSE)