Grouping data and descriptive statistics

How to set statistical aggregators for a single column

Aggregators provide summary statistics for grouped rows.

The following statistical aggregators are available:

The follow howtos will have examples of workflows involving grouping of data and statistical aggregation.

The following examples use the file sample.tsv.

How to group data (frequency table, pivot table, describe table,)

How to make a pivot table frequency table, pivot table, describe table,)

1. Move to the column A with the independent variable, and press ! to mark it as a key column to group by.
2. Move to a numeric column B, and press + to add an aggregator to that column, so that the aggregator will be applied to each group of values.
3. Make sure column B has a numeric type: int (#), float (%), currency ($), or date (@).
4. Move to the column C with the dependent categorical variable to be pivoted, and press Shift+W (pivot) to pivot on that column. The pivoted sheet then will have a column for each distinct value in the source column.

How to create a frequency chart

How to make a histogram

Question How many of each Item were sold?

1. Move the cursor to the Item column.
2. Press Shift+F to open the Frequency table.

How to use the Frequency table to view the results of statistical aggregation

Question What was the monthly revenue?

1. On the OrderDate column, type ; followed by (\d+-\d+) to create a column with only the year and the month using regex capture groups.
2. Press - to hide the OrderDate column.
3. On the **OrderDate_re0** column, type ^ followed by OrderDate to rename it.
4. On the Total column, press $ to set its type to currency.
5. Type + followed by sum to add a statistical aggregator to Total.
6. On the OrderDate column type Shift+F to open the Frequency table.
7. On the OrderDate column, press [ to sort the table in chrononological order.
8. On the **sum_Total** column, type ^ followed by Revenue to rename the column.

How to calculate some descriptive statistics

1. Press Shift+I to open the Describe sheet.

How to filter for grouped rows

1. Press Shift+F to open the Frequency table.
2. Press s or t on the groups you are interested in to select those entries in the source sheet.
3. Press q or Ctrl+^ to return to the source sheet.
4. Press " to open a duplicate sheet with selected rows.

or

1. Press Shift+F to open the Frequency table.
2. Press Enter on the grouping you are interested in to open a sheet of the source rows that are part of that group.

How to filter for described rows

1. Press Shift+I to open the Describe sheet.
2. Use zs to select rows on source sheet which are being described in the cells of interest.
3. Press q or Ctrl+^ to return to the source sheet.
4. Press " to open a duplicate sheet with selected rows.

or

1. Press Shift+I to open the Describe sheet.
2. Press zEnter open copy of source sheet with rows being described in the current cell of interest.

How to filter for the rows aggregated in a pivot table

Enter/zEnter can both be used in the Pivot table to open a sheet of the source rows which are aggregated in the current pivot row/cell.

How to combine cells in one for column for matching rows in another

This tutorial shows you how to go from this dataset:

to

in VisiData.

1. On the value column, type + followed by list to add to it a list aggregator.
2. Press Shift+F on the field column to open the Frequency table.
3. Type = followed by ';'.join(value_list) to add an expression column with the joined values.