# Example 16: Grouping

Data on reports is frequently grouped in some way. The reporter package offers several features to identify and manage these groups. Here are some of the highlights.

## Group Border

The reporter package can draw border lines to separate different groups. To create the border line, set `group_border = TRUE` on the `define()` function.

Here is an example:

    library(reporter)

    # Create temp file name
    tmp <- file.path(tempdir(), "example16a.pdf")

    # Create data
    arm <- c(rep("A", 3), rep("B", 2), rep("C", 3), rep("D", 2))
    subjid <- 100:109
    name <- c("Quintana, Gabriel", "Allison, Blas", "Minniear, Presley",
              "al-Kazemi, Najwa", "Schaffer, Ashley", "Laner, Tahma",
              "Perry, Sean", "Crews, Deshawn Joseph", "Person, Ladon",
              "Smith, Shaileigh")
    sex <- c("M", "F", "F", "M", "M", "F", "M", "F", "F", "M")
    age <- c(41, 53, 43, 39, 47, 52, 21, 38, 62, 26)

    df <- data.frame(arm, subjid, name, sex, age, stringsAsFactors = FALSE)
    df <- rbind(df, df, df, df)

    # Output with group_border
    tbl1 <- create_table(df, first_row_blank = FALSE, borders = "outside") %>%
      define(subjid, label = "Subject ID for a patient", n = 10, align = "left",
             width = 1) %>%
      define(name, label = "Subject Name", width = 1) %>%
      define(sex, label = "Sex", n = 10, align = "center") %>%
      define(age, label = "Age", n = 10) %>%
      define(arm, label = "Arm",
             dedupe = TRUE,
             group_border = TRUE)

    rpt <- create_report(tmp, output_type = "pdf", font = "Arial",
                         font_size = 10) %>%
      titles(c("Table 1.0", "This is a table with group border"), align = "center") %>%
      add_content(tbl1) %>%
      set_margins(top = 1, bottom = 1)

    res <- write_report(rpt)

## Break Label

For some types of reports, it is desirable to have a label that indicates when a group has been broken across pages. This feature is supported with the “break_label” parameter on the `define()` function. In the example below, the “break_label” is assigned a value of “(Continued)”:

    library(reporter)

    fp <- file.path(tempdir(), "example16b.pdf")

    # Prepare data
    adae <- data.frame(
      total = rep("Number of subject with adverse events", 53),
      AESOC = c(NA,
                rep("General disorders and administration site conditions", 9),
                rep("Hepatobiliary disorders", 5),
                rep("Infections and infestations", 25),
                rep("Injury, poisoning and procedural complications", 13)),
      AEDECOD = c(NA,
                  NA, rep("APPLICATION SITE ERYTHEMA", 4), rep("INFLUENZA LIKE ILLNESS", 4),
                  NA, rep("GALLBLADDER DISORDER", 4),
                  NA, rep("BRONCHITIS", 4), rep("NAIL INFECTION", 4), rep("PARONYCHIA", 4),
                  rep("RASH PUSTULAR", 4), rep("RESPIRATORY TRACT INFECTION", 4),
                  rep("RHINITIS", 4),
                  NA, rep("FALL", 4), rep("HEAT CRAMPS", 4), rep("MUSCLE INJURY", 4)
      )
    )

    adae$aedecod_seq <- rep(NA, nrow(adae))
    non_na_idx <- !is.na(adae$AEDECOD)
    adae$aedecod_seq[non_na_idx] <- ave(adae$AEDECOD[non_na_idx], adae$AEDECOD[non_na_idx], FUN = seq_along)

    adae$AESEV <- adae$aedecod_seq
    adae$AESEV[adae$AESEV == "1"] <- NA
    adae$AESEV[adae$AESEV == "2"] <- "Mild"
    adae$AESEV[adae$AESEV == "3"] <- "Moderate"
    adae$AESEV[adae$AESEV == "4"] <- "Severe"

    adae$trt1 <- "x ( x.x%)"
    adae$trt2 <- "x ( x.x%)"
    adae$trt3 <- "x ( x.x%)"

    adae$aedecod_id <- rep(NA, nrow(adae))
    adae$aedecod_id[non_na_idx] <- ave(adae$AEDECOD[non_na_idx], adae$AESOC[non_na_idx],
                                       FUN = function(x){as.numeric(factor(x, levels = unique(x)))})

    adae$blank_grp <- paste(adae$total,
                            adae$AESOC,
                            ifelse(adae$aedecod_id == 1,NA,adae$AEDECOD),
                            sep = "|")

    adae <- adae[, setdiff(names(adae), c("aedecod_seq", "aedecod_id"))]

    # Output
    custom_n_format <- function(x){
      return(paste0("\n(N = ",x,")\nn(%)"))
    }

    current_date <- gsub(" ","",toupper(format(Sys.Date(),"%d %b %Y")))
    current_time <- substr(Sys.time(),12,19)
    output_name <- "example16c.pdf"
    program_path <- "/dummy/tables/t-teae-soc-pt-gr-saf.R"

    total_width <- 6
    trt_width <- 1.04
    item_width <- total_width - (trt_width*3)

    tbl <- create_table(adae,
                        borders = "outside",
                        n_format = custom_n_format) %>%

      # ----- Column setting -----#
      column_defaults(from = trt1, to = trt3, align = "center", width = trt_width) %>%
      define(blank_grp, blank_before = T, visible = FALSE) %>%
      stub(vars = c("total", "AESOC", "AEDECOD", "AESEV"),
           label = "System Organ Class\n  Preferred Term\n    Grade",
           width = item_width) %>%
      define(AESOC, break_label = "(Continued)") %>%
      define(AEDECOD, indent = 0.16, break_label = "(Continued)") %>%
      define(AESEV, indent = 0.32) %>%
      define(trt1, label = "Treatment A", n=11) %>%
      define(trt2, label = "Treatment B", n=7) %>%
      define(trt3, label = "Treatment C", n=15) %>%

      # ----- Footnote setting -----#
      footnotes("Page [pg] of [tpg]", align = "right", blank_row = "none", valign = "top") %>%
      footnotes("Safety Analysis Set includes all subjects who are received at least one dose of study drug.",
                align = "left", blank_row = "none", valign = "top") %>%
      footnotes("The analysis is performed on the maximum severity grade.",
                align = "left", blank_row = "none", valign = "top") %>%
      footnotes("Coded using MedDRA version 22.1.",
                align = "left", blank_row = "none", valign = "top") %>%
      footnotes(paste0("Program: ", program_path), italics = TRUE)

    sty <- create_style(font_name = "Arial",
                        font_size = 9)

    rpt <- create_report(fp,
                         orientation = "landscape",
                         output_type = "PDF")  %>%
      add_style(style = sty) %>%
      set_margins(top = 1, bottom = 0.75, right = 1, left = 1.5) %>%
      add_content(tbl) %>%

      # ----- Title setting -----#
      titles("Table 14-6.1.3.1.  Treatment-emergent Adverse Events by System Organ Class,",
             "Preferred Term and Grade",
             "(Safety Analysis Set)",
             bold = T,
             font_size = 11)

    # Write the report
    res <- write_report(rpt)

    # Uncomment to view
    # file.show(res$path)

## Group Cohesion

You many also want to avoid splitting groups across pages altogether. To keep groups together on the same page, you can use the “group_cohesion” parameter on the `define()` function.

To illustrate, we will make a small modification to the code above to turn on group cohesion:

    define(AESOC, break_label = "(Continued)", group_cohesion = TRUE)
    define(AEDECOD, indent = 0.16, break_label = "(Continued)", group_cohesion = TRUE)

Now the result is as follows:

With the above modification, the group “Infections and infestations” is still split because it is a large group, and there is no way to avoid splitting it across multiple pages. However, the other breaks have all been avoided by moving groups to the next page. In this way, the report looks nicer and becomes more readable.

## Multiple Group Cohesion

The group cohesion feature also works with multiple columns. To illustrate, let’s look at another example:

    library(reporter)

    fp <- file.path(tempdir(), "example16b.pdf")

    # Create data
    dat <- iris[1:91,]

    dat$group_1 <- c(
      rep("A", 14),
      rep("B", 6),
      rep("C", 22),
      rep("D", 18),
      rep("E", 31)
    )

    dat$group_2 <- c(
      rep("Flower A\nSubgroup A1", 14),
      rep("Flower B\nSubgroup B1", 3),
      rep("Flower B\nSubgroup B2", 3),
      c(rep("Flower C1", 17)),
      c(rep("Flower C2", 5)),
      c(rep("Flower D", 16), rep("Flower D\nSubgroup D1", 2)),
      c(rep("Flower E1", 2)),
      c(rep("Flower E2", 29))
    )

    dat <- dat[, c("group_1", "group_2", "Sepal.Length",
                   "Sepal.Width", "Petal.Length","Petal.Width")]

    # Create table
    tbl <- create_table(dat, borders = "outside") %>%
      define(group_1, group_cohesion = TRUE, label = "Region", blank_after = T,
             width = 1.2) %>%
      define(group_2, group_cohesion = TRUE, label = "Sector")

    # Create report
    rpt <- create_report(fp, output_type = "pdf", font = "Arial",
                         font_size = 10, orientation = "landscape") %>%
      titles("Table 1.0", "Analysis of Iris Flowers") %>%
      set_margins(top = 1, bottom = 1) %>%
      add_content(tbl) %>%
      footnotes("Program: /test/example16b.R",
                "Output: /test/example16b.pdf")

    # Output report
    res <- write_report(rpt)

We can see above that there is still space at the end of page 1, but it’s not enough for all of region B. To keep region B together, it is therefore moved to page 2.

After region B moves to page 2, the remaining space is not enough for all of region C. And we cannot move all of region C to page 3, because it is too big.

As a result, region C will be split between pages 2 and 3. However, because we engaged group cohesion for both Region and Sector, reporter will try to keep the sectors on the same page. Therefore, all of sector “Flower C2” is moved to page 3.

#### Logic of Group Cohesion

The logic of group cohesion is very simple. If a group is to be split, the group will be moved to next page only if the current page is at least 80% full. Accordingly, Region B moves to the next page because Region A occupies at least 80% of the page. Similarly, Sector C2 moves to the next page because the combined data from Region B and Sector C1 reaches the 80% threshold.

When `group_cohesion = TRUE`, the default strength of group cohesion is 0.2, which means the required proportion is `1 - 0.2 = 0.8`. Users can change the required proportion by assigning more strength, such as `group_cohesion = 0.6`, which means the requirement of proportion is 0.4. Once the previous group has reached 40% of page, the next group can be moved to a new page if the remaining space is not enough. That is to say, the stronger the group cohesion, the lower the required proportion, and the less likely the group is to split.