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Read EMA records into a tidy data frame

Source: R/read_ema.R
read_ema.Rd

Reads the CSV or JSON produced by a mobile collection tool and returns a data frame with parsed timestamps and a study-day index, ready for validate_ema() and compliance().

Usage

read_ema(path, start_date = NULL, tz = "UTC", timestamp_col = "timestamp")

Arguments

path

Path to a .csv or .json file.

start_date

Date (or something as.Date() accepts) on which the study began. Used to compute study_day when the file does not already have it.

tz

Time zone to interpret timestamps in. Defaults to "UTC", which matches the ISO 8601 output of the companion app.

timestamp_col

Name of the column holding the timestamp. Real files call it many things (datetime, time, recorded_at); give the name here and it is renamed to timestamp on the way in.

Value

A data frame with timestamp as POSIXct, study_day as integer when derivable, and all other columns unchanged.

Details

The expected columns are timestamp plus whatever was measured. Only timestamp is required. If start_date is supplied (or the file already carries a study_day column) a study_day index is attached, counting from 1 on the first day of the study.

Examples

f <- system.file("extdata", "example_ema.csv", package = "nof1kit")
if (nzchar(f)) head(read_ema(f))