# User Guide
A general overview of the motivation for and functionality of Plot Curve, as implemented in
**seeq-plot-curve** is provided in this section.
## The Problem
When working with time series data, it is very common to want to create a new signal based on a relationship or function with
an existing signal. When the formula for the calculation is simple and known, it can be directly input into Seeq
via the formula editor. But many relationships are empirical in nature, represented by data points which describe the
relationship between variables.
Some examples may include :
- Equipment Curves
- A [pump curve](https://www.pumpsandsystems.com/understanding-pump-curves) providing the relationships between flow, head, efficiency, etc
- A [valve curve](https://www.industrialcontrolsonline.com/training/online/controlling-flow-ball-valves) describing the relationship between the flow coefficient of a valve and its opening percentage
- Experimental Data
- Product properties (i.e. blend ratio properties, property estimation)
- Physical effects of additives (i.e. [drag reducing agents](https://pdfs.semanticscholar.org/2353/62a58dbe58225041b237051a0c5bcf878879.pdf))
There also may be many unique curves that we wish to integrate into Seeq, and the units may (or may not) match the units
of the input signal. This process can be time-consuming and error-prone.
*Plot Curve* is a minimal tool to solve the problem of efficiently fitting tabular data with polynomial functions that can
be pushed to Seeq as formulas. It allows for previewing of the functions and manual selection of the polynomial order.
## Usage
### Step 1 - Select a File
- Add all relevant dataset signals to the trend view. Any time range is acceptable, but any dependent signals should
be added to the trend view *before* launching the Plot Curve Application.
-
- From the Tools tab in Workbench, select Add On Tools followed by *PlotCurve*. After a moment the tool will load, you
will be prompted to select the data to be plotted. Some instructions are provided on this screen, indicating the
required file format, and [providing a link to supported units](https://seeq.atlassian.net/wiki/spaces/KB/pages/112761878/Units+of+Measure+UOM).
*Units must be in a Seeq supported format to allow for proper conversion.*