has_data: Check whether the student created a given object

In oonyambu/stats_102A: Grade stats 102A (UCLA)

Description

Determine whether a student created a particular object

Usage

has_data(student_dir, data_name, mode, check = alist())

Arguments

student_dir	The directory that containts the students folders
data_name	A character that shows the name of the object intended to be created
mode	The mode of the object to be created. Ie the result which would be obtained if we were to run 'base::mode(object)'
check	A alist of parameters to that the object ougth to satisfy. This is given as a pair of a function and the left hans side and what it ought to satisfy on the right. Look at the examples.

Value

The function returns a dataframe with the StudentID, and whether the student created the object

Examples

#Assume gradebook has 150 row, 15 columns, 2 of the columns are named as 'UID' and 'Section'

# Check whether the student created a dataframe called 'gradebook'

## Not run: has_data("../students", "gradebook", "list")

# Check whether the student created a dataframe called 'gradebook' with atleast 150 rows

## Not run: has_data("../students", "gradebook", "list", alist(nrow >= 150))

# Check whether the student created a dataframe called 'gradebook' with atleast 150 rows
# must contain some specified named columns and has 15 columns

nms <- c("UID","Section")
chk <- alist(nrow >= 150, names = nms, ncol == 15)

# Note that for containing, we use a single equal sign, while for equality we use "=="
# Also note that the left hand side of the pair is a function to evaluate.
# eg ncol(gradebook)==15 is what will be computed. You can have a customed function
# on the left hand side. On the right hand is the value to be checked on

## Not run: has_data("../students", "gradebook", "list", chk)

oonyambu/stats_102A documentation built on July 21, 2020, 7:28 a.m.