Column Properties

Column properties are a handy way to build mathematical expressions using a range of numbers, specifically a column of values. 

To refer to them, type the name of the column followed by a ‘.’ and the property name. 

For example, ‘name.sum’ returns a single value, the sum of a column. In the table below, the column Percentage is calculated using the expression:   x / x.sum * 100 . 

Other column properties return a column of values. For example. ‘name.isum’ returns the  running sum of a column. Enter the column property alone as a expression column (as in the column Running Sum below) or in more complicated expressions/calculations.

Single values

Properties that return a single value.

Name	Description
min	Minimum of the column
max	Maximum of a column
length	Number of the last non-empty row
range	Maximum minus the minimum
average	Mean of the column
median	Median of the column
sigma	Population standard deviation (σ)
s	Sample standard deviation (unbiased estimate of sigma)
sem	Standard error of the mean
first	Value of the first non-empty row
last	Value of the last non-empty row
sum	Sum of all finite values

Multiple values

Properties that return a column of values.

Name	Description
isum	Incremental sum, e.g., row 4 is the sum of rows 1,2,3 and 4. Restarts where there is a gap.
rmax	Maximum so far.
rmin	Minimum so far.
count	How many times this row value has appeared up to the current row. For example, if you have row values 3.1,1.1,2.1,1.1,1.1,2.1  the count has the row values 1,1,1,2,3,2. If you draw (x,x.count) with a Points command, you will see a shape of a histogram using points.
totalcount	How many times this value shows up in a column. If you have the list 3.1,1.1,2.1,1.1,1.1,2.1 the totalcount variable is 1,3,2,3,3,2
sortedindex	Where this entry will be in a sorted list. 3.1,1.1,2.1,1.1,1.1,2.1 the property is the list 6,1,4,2,3,5.
rank	Where this entry is in a ranked list.  Repeated values have the same rank. If you have the list 3.1,1.1,2.1,1.1,1.1,2.1, the rank is 1,5,2,4,4,2. This is because 3.1 is the highest value (top rank), 2.1 shows up twice so both have rank 2, and not 2 and 3.
sortwith	Sort a column by doing x(x.sortwith), or reorder a column using y(x.sortwith).
delta	The difference between two adjacent rows. The first row is empty.
unwrap2π	For angles, for example, computed with the angle(x,y) function the value is mapped onto a whole period such as [-π,π]. The issue with that is that when you wrap around the circle the value jumps by 2π.  This column will make sure that the gap between adjacent rows is less than π in absolute value.  That means that if your row entries for x are π/2,π,-π/2,0,π/2 the output for x.unwrap2π is π/2,π,3π/2,2π,5π/2.
unwrap1	Similar to the last command, except the period is 1. So 0,0.5,0,0.5,0 maps to 0,0.5,1,1.5,2.
unwrap360	Same except the period is 360.