Look up each principle, its source, and the functions that implement it.
The table also records whether tufte_audit() can check it.
Value
A tibble with columns principle, source,
statement, implemented_by, audited and
criterion. implemented_by is a comma-separated list of
functions in this package, or NA for the principles no function
reaches. audited and criterion are both logical:
audited says whether any function reports on the principle, and
criterion whether Tufte states a threshold, so that
criterion is the column that separates what the audit grades from
what it only measures.
Details
The criterion column identifies principles with a stated rule, such
as a zero baseline for bars or a lie factor between 0.95 and 1.05. Tufte asks
that data-ink be maximised "within reason" and that data density increase,
but doesn't give them numerical targets. The audit reports those measurements
without grading them.
Principles the package can't check are included with audited = FALSE.
I've kept them in the table so the limits of the audit are visible.
Examples
tufte_principles()
#> # A tibble: 26 × 6
#> principle source statement implemented_by audited criterion
#> <chr> <chr> <chr> <chr> <lgl> <lgl>
#> 1 Above all else show the da… VDQI … The grap… theme_tufte() FALSE FALSE
#> 2 Maximise the data-ink ratio VDQI … A large … data_ink_rati… TRUE FALSE
#> 3 Erase non-data ink VDQI … Ink that… theme_tufte() TRUE TRUE
#> 4 Erase redundant data-ink VDQI … Ink that… geom_col_tuft… TRUE TRUE
#> 5 Revise and edit VDQI … Graphics… check_labels_… TRUE TRUE
#> 6 The range-frame VDQI … The fram… geom_rangefra… TRUE TRUE
#> 7 The dot-dash plot VDQI … The axis… geom_dotdash() FALSE FALSE
#> 8 The lie factor VDQI … The effe… lie_factor() TRUE TRUE
#> 9 Graphical integrity VDQI … Bars mea… tufte_audit() TRUE TRUE
#> 10 Maximise data density VDQI … A graphi… data_density(… TRUE FALSE
#> # ℹ 16 more rows
# Principles Tufte states a testable criterion for:
subset(tufte_principles(), criterion)$principle
#> [1] "Erase non-data ink" "Erase redundant data-ink"
#> [3] "Revise and edit" "The range-frame"
#> [5] "The lie factor" "Graphical integrity"
#> [7] "Proportion and scale" "Legibility"
#> [9] "Integrate word, number and image" "Documentation"