intermittent

The goal of intermittent is to assist IR analysts with ‘term’ data formats originating in various student information systems (SIS). Currently, two origins are supported: SIMS and Campus Solutions.

intermittent is built with vctrs, a package that makes it easy to create S3 vectors.

Sims	CS	Label
20124	2127	Fall 2012
20132	2133	Spring 2013
20133	2135	Summer 2013
20134	2137	Fall 2013

Installation

You can install intermittent from GitHub with:

remotes::install_github("ir-sfsu/intermittent")

The ‘term’ class

Create a term object with term and indicate an origin.

library(intermittent)
x <- term(2123, origin = "cs")
x
#> <term[1]>
#> [1]  2123
attributes(x)
#> $origin
#> [1] "cs"
#> 
#> $class
#> [1] "term"       "vctrs_vctr"

Arithmetic

R ‘understands’ term 2123 to be equivilent of ‘Spring 2012’.

### Increment the term
x + 1 # To Fall 2012
#> <term[1]>
#> [1]  2127
x + 2 # To Spring 2013
#> <term[1]>
#> [1]  2133
x + 5 # To Fall 2014
#> <term[1]>
#> [1]  2147

x - 1 # To Fall 2011
#> <term[1]>
#> [1]  2117
x - 3 # To Fall 2010
#> <term[1]>
#> [1]  2107

### Comparison
y <- term(2133, "cs")
x < y 
#> [1] TRUE

Subtract a term from a term to count the terms in-between. This is useful when counting the number of terms to graduation.

grad_term <- term(20182, "sims") # Spring 2018
matric_term <- term(20144, "sims") # Fall 2014
grad_term - matric_term 
#> [1] 8

Helpers

Get the label, academic year, or calendar year for any term object.

label_term(x)
#> [1] "Spring 2012"
acad_year(x)
#> [1] "2011-12"
cal_year(x)
#> [1] 2012

Create a sequence of terms with a seq method.

# Fall 2010 to Spring 2016 with a "sims" origin
sims_terms <- seq(term(20104), 20162)
sims_terms
#> <term[12]>
#>  [1] 20104 20112 20114 20122 20124 20132 20134 20142 20144 20152 20154 20162

min(sims_terms)
#> <term[1]>
#> [1]  20104
max(sims_terms)
#> <term[1]>
#> [1]  20162
median(sims_terms) # Retrieve the 'middle' term
#> <term[1]>
#> [1] 20132
range(sims_terms) # Retrieve the min/max
#> <term[2]>
#> [1]  20104  20162

Use with packages like dplyr.

library(dplyr)
library(tibble)

tibble(term = c(2123, 2127, 2133, 2137)) %>% 
  mutate(
    term = as_term(term, "cs"),
    second_term = term + 1,
    grad_term = as_term(2163, "cs"),
    terms_to_degree = grad_term - term, # or term_duration(grad_term, term)
    term_label = label_term(term),
    academic_year = acad_year(term),
    year = cal_year(term)
  )
#> # A tibble: 4 x 7
#>     term second_term grad_term terms_to_degree term_label  academic_year  year
#>   <term>      <term>    <term>           <int> <chr>       <chr>         <dbl>
#> 1   2123        2127      2163               9 Spring 2012 2011-12        2012
#> 2   2127        2133      2163               8 Fall 2012   2012-13        2012
#> 3   2133        2137      2163               7 Spring 2013 2012-13        2013
#> 4   2137        2143      2163               6 Fall 2013   2013-14        2013

Other helpers and operators

fall16 <- term(2167, origin = "cs")
spring20 <- term(2203, origin = "cs")
label_term(fall16)
#> [1] "Fall 2016"
label_term(spring20)
#> [1] "Spring 2020"

# Get next 5 terms
label_term(get_next(fall16, 5))
#> [1] "Fall 2016"   "Spring 2017" "Fall 2017"   "Spring 2018" "Fall 2018"  
#> [6] "Spring 2019"

# Get last 5 terms
label_term(get_last(spring20, 5))
#> [1] "Fall 2017"   "Spring 2018" "Fall 2018"   "Spring 2019" "Fall 2019"  
#> [6] "Spring 2020"

# Get next 5 fall terms
label_term(fall16 %+F% 5)
#> [1] "Fall 2016" "Fall 2017" "Fall 2018" "Fall 2019" "Fall 2020" "Fall 2021"

# Get last 5 spring terms
label_term(spring20 %-S% 5)
#> [1] "Spring 2015" "Spring 2016" "Spring 2017" "Spring 2018" "Spring 2019"
#> [6] "Spring 2020"

Package Options - Include Summer Terms?

You may have noticed that the default sequencing, addition, and subtraction do not account for Summer terms. To change this behavior, change the package options:

getOption("intermittent.use_terms")
#> [1] "fasp"
seq(term(2127, "cs"), 2173)
#> <term[10]>
#>  [1] 2127 2133 2137 2143 2147 2153 2157 2163 2167 2173

options(intermittent.use_terms = "all")
seq(term(2127, "cs"), 2173)
#> <term[14]>
#>  [1] 2127 2133 2135 2137 2143 2145 2147 2153 2155 2157 2163 2165 2167 2173

Future work

• Other SIS origins?
• Other methods?
• Tests