# Spotfire Functions — Lines & Curves

• Have you tried to use different lines and curves functions but run into issues?
• Do you need further clarification on the differences between the different lines and curves options?

This week’s post is all about lines and curves.  The lines and curves features in Spotfire are incredibly useful, but they aren’t explained or organized well in the application to help the user understand when to use them or which one to use for a given scenario.  Therefore, I am writing a 5-part series on lines and curves that will cover Line from Column Values, Line from Data Table, Curve Draw and Curve from Data Table.  There are more options in lines and curves, but the rest are fairly easy to figure out.  These, not so much.  Today’s post will cover these four functions at a high level, and then I will continue to post greater detail for the next four weeks.

Curve Draw

Curve draw will plot a line based on an equation specified by the user where y is a function of x.  In the example below, I am plotting a line calculated by multiplying 2 times the x values on the plot.  The user may utilize functions and properties in the expression but not columns of data.

Curve from Data Table

Curve from Data Table calculates an equation based on x values, but differs from Curve Draw in that the user can also reference table columns and properties.

Line from Column Values

Line from Column Values will add data from any table in the DXP file to a visualization.  If the user is adding data from a different table, it is imperative that the x values specified in the Line from Column Values match the values on the x axis of the visualization.  This is commonly used to add type curves or forecasts to production data.  The user can reference only a single column of data and cannot apply expressions or otherwise use functions and properties.

Line from Data Table

Line from Data Table will add straight lines and only straight lines (horizontal and vertical) to a visualization from a table.  This is useful for adding targets to a visualizaiton. The user can reference only a single column of data and cannot apply expressions or otherwise use functions and properties.

Stay tuned over the next four weeks for examples using each of these Lines & Curves functions.