Prepare spaghetti / profile data for plotting

Validates a long-format repeated-measures data frame and returns an hv_spaghetti object. Call plot.hv_spaghetti on the result to obtain a bare ggplot2 trajectory plot that you can decorate with colour scales, axis labels, and hv_theme.

Usage

hv_spaghetti(
  data,
  x_col = "time",
  y_col = "value",
  id_col = "id",
  colour_col = NULL
)

Arguments

data

Data frame; one row per observation per subject.

x_col

Name of the time column. Default "time".

y_col

Name of the outcome column. Default "value".

id_col

Name of the subject-identifier column (used as the group aesthetic for line continuity). Default "id".

colour_col

Name of the column to map to line colour, or NULL for a single uniform colour. Default NULL.

Value

An object of class c("hv_spaghetti", "hv_data"); call plot() on the result to render the figure — see plot.hv_spaghetti. The list contains:

$data

The validated input data frame.

$meta

Named list: x_col, y_col, id_col, colour_col, n_subjects, n_obs.

$tables

Empty list.

See also

plot.hv_spaghetti to render as a ggplot2 figure, hv_theme for the publication theme, sample_spaghetti_data for example data.

Other Spaghetti plot: plot.hv_spaghetti()

Examples

dta <- sample_spaghetti_data(n_patients = 150, seed = 42)

# 1. Build data object
sp <- hv_spaghetti(dta, colour_col = "group")
sp  # prints subject count, observation count, column mapping
#> <hv_spaghetti>
#>   N subjects  : 150  (594 observations)
#>   x / y / id  : time / value / id
#>   Colour col  : group

# 2. Bare plot -- undecorated ggplot returned by plot.hv_spaghetti
p <- plot(sp)

# 3. Decorate: colour palette, axis labels, theme
p +
  ggplot2::scale_colour_manual(
    values = c(Female = "firebrick", Male = "steelblue"), name = NULL
  ) +
  ggplot2::labs(x = "Years after Operation",
                y = "AV Mean Gradient (mmHg)") +
  hv_theme("poster")
#> Warning: No shared levels found between `names(values)` of the manual scale and the
#> data's colour values.
#> Warning: Ignoring empty aesthetic: `colour`.