# 29.12.3 Piper/Trilinear Diagram

## Data Requirements

A piper (trilinear) diagram is a specialized graph type for charting the chemistry of a water samples.

Origin's piper diagram is created from worksheet data with column plot designations XYZXYZ. Each column contains the percentage value of each ion group. Column order is critical and should be: $Ca^{2+}, Mg^{2+}, Na^{+}+K^{+}, Cl^{-}, SO_{4}^{2-}, CO_{3}^{2-}+HCO_{3}^{-}$ The percentage value of each cation group is calculated based on the total concentration of calcium, magnesium, and sodium plus potassium cations; The percentage of each anion group is based on the total concentration of sulfate, chloride, and carbonate plus hydrogen carbonate anions.

## Creating the Graph

Highlight the source data and open the plotpiper dialog by either of the following:

• select Plot > Specialized: Piper from top menu

OR

• click the button in the 2D Graphs toolbar.

### The plotpiper Dialog Box

Input Specify the XYZXYZ input data range for the piper plot. Specify the column used for the sample ID. This column will be used as the symbol color and shape indexing column in the piper plot, and this column will supply labels in the point by point legend. Specify the data range for the amount of total dissolved solid. This column will be used to control symbol size in Layer 1 (the "diamond") of the piper plot. Specify where to output the graph.

## Controls

Three worksheet templates are provided to convert the original concentration data to percentage values and organize them according to data requirements for piper plot.

To open these three templates, you can

1. Select Help: Open Folder: Program Folder menu to open the Origin's program folder.
2. Open the sub-folder "\Templates\Analysis", all the desired templates will be listed there: "Convert MEq to Percentage.ogw", "Convert mgl to Percentage.ogw" and "Convert PPM to Percentage.ogw".
3. Drag and drop one of them to Origin workspace to open it.

To control the gaps between each layer (i.e. each rhomb), you can

• Open the Layer Properties dialog by Format: Layer menu item and go to the Size/Speed tab for Layer 2 and change the value in the Left text box.

A user-defined dataset can be used to index the color/shape/interior of the symbols in the piper chart. You can also customize the increment list of color, shape and interior in the Increment Editor, Shape List and Interior List tabs in the Plot Details dialog.