dataset_from_gen: Collect samples from generator and store in rds or pickle...

In GenomeNet/deepG: Deep Learning for Genome Sequence Data

Collect samples from generator and store in rds or pickle file.

Description

Repeatedly generate samples with data generator and store output. Creates a separate rds or pickle file in output_path for each batch.

Usage

dataset_from_gen(
  output_path,
  iterations = 10,
  train_type = "lm",
  output_format = "target_right",
  path_corpus,
  batch_size = 32,
  maxlen = 250,
  step = NULL,
  vocabulary = c("a", "c", "g", "t"),
  shuffle = FALSE,
  set_learning = NULL,
  seed = NULL,
  random_sampling = FALSE,
  store_format = "rds",
  file_name_start = "batch_",
  masked_lm = NULL,
  ...
)

Arguments

output_path	Output directory. Output files will be named output_path + file_name_start + x + ".rds" or ".pickle", where x is an index (from 1 to iterations) and file ending depends on store_format argument.
iterations	Number of batches (output files) to create.
train_type	Either "lm", "lm_rds", "masked_lm" for language model; "label_header", "label_folder", "label_csv", "label_rds" for classification or "dummy_gen". Language model is trained to predict character(s) in a sequence. "label_header"/"label_folder"/"label_csv" are trained to predict a corresponding class given a sequence as input. If "label_header", class will be read from fasta headers. If "label_folder", class will be read from folder, i.e. all files in one folder must belong to the same class. If "label_csv", targets are read from a csv file. This file should have one column named "file". The targets then correspond to entries in that row (except "file" column). Example: if we are currently working with a file called "a.fasta" and corresponding label is "label_1", there should be a row in our csv file file label_1 label_2 "a.fasta" 1 0 If "label_rds", generator will iterate over set of .rds files containing each a list of input and target tensors. Not implemented for model with multiple inputs. If "lm_rds", generator will iterate over set of .rds files and will split tensor according to target_len argument (targets are last target_len nucleotides of each sequence). If "dummy_gen", generator creates random data once and repeatedly feeds these to model. If "masked_lm", generator maskes some parts of the input. See masked_lm argument for details.
output_format	Determines shape of output tensor for language model. Either "target_right", "target_middle_lstm", "target_middle_cnn" or "wavenet". Assume a sequence "AACCGTA". Output correspond as follows ⁠"target_right": X = "AACCGT", Y = "A"⁠ ⁠"target_middle_lstm": X = (X_1 = "AAC", X_2 = "ATG"), Y = "C"⁠ (note reversed order of X_2) ⁠"target_middle_cnn": X = "AACGTA", Y = "C"⁠ ⁠"wavenet": X = "AACCGT", Y = "ACCGTA"⁠
path_corpus	Input directory where fasta files are located or path to single file ending with fasta or fastq (as specified in format argument). Can also be a list of directories and/or files.
batch_size	Number of samples in one batch.
maxlen	Length of predictor sequence.
step	How often to take a sample.
vocabulary	Vector of allowed characters. Characters outside vocabulary get encoded as specified in ambiguous_nuc.
shuffle	Whether to shuffle samples within each batch.
set_learning	When you want to assign one label to set of samples. Only implemented for train_type = "label_folder". Input is a list with the following parameters samples_per_target: how many samples to use for one target. maxlen: length of one sample. reshape_mode: ⁠"time_dist", "multi_input"⁠ or "concat". If reshape_mode is "multi_input", generator will produce samples_per_target separate inputs, each of length maxlen (model should have samples_per_target input layers). If reshape_mode is "time_dist", generator will produce a 4D input array. The dimensions correspond to ⁠(batch_size, samples_per_target, maxlen, length(vocabulary))⁠. If reshape_mode is "concat", generator will concatenate samples_per_target sequences of length maxlen to one long sequence. If reshape_mode is "concat", there is an additional buffer_len argument. If buffer_len is an integer, the subsequences are interspaced with buffer_len rows. The input length is (maxlen * samples_per_target) + buffer_len * (samples_per_target - 1).
seed	Sets seed for set.seed function for reproducible results.
random_sampling	Whether samples should be taken from random positions when using max_samples argument. If FALSE random samples are taken from a consecutive subsequence.
store_format	Either "rds" or "pickle".
file_name_start	Start of output file names.
masked_lm	If not NULL, input and target are equal except some parts of the input are masked or random. Must be list with the following arguments: mask_rate: Rate of input to mask (rate of input to replace with mask token). random_rate: Rate of input to set to random token. identity_rate: Rate of input where sample weights are applied but input and output are identical. include_sw: Whether to include sample weights. block_len (optional): Masked/random/identity regions appear in blocks of size block_len.
...	further generator options. See get_generator.

Value

None. Function writes data to files and does not return a value.

Examples

# create dummy fasta files
temp_dir <- tempfile()
dir.create(temp_dir)
create_dummy_data(file_path = temp_dir,
                  num_files = 3,
                  seq_length = 8, 
                  num_seq = 2)

# extract samples
out_dir <- tempfile()
dir.create(out_dir)
dataset_from_gen(output_path = out_dir,
                 iterations = 10,
                 train_type = "lm",
                 output_format = "target_right",
                 path_corpus = temp_dir, 
                 batch_size = 32,
                 maxlen = 5,
                 step = 1,
                 file_name_start = "batch_")

list.files(out_dir)

GenomeNet/deepG documentation built on Dec. 24, 2024, 12:11 p.m.