Waterfall plots, colloquially known as “spectragrams” are extremely useful for displaying multiple sets of data across the same time series, allowing readers to easily distinguish the influence of variables across multiple iterations.
When making these plots, oftentimes you’ll want to connect a line across the end points of your data to illustrate how these variables, in this case the pressure and amperage of a system, influence one another across a time series. In the coming Origin 2016 SR1 release, this can be easily accomplished with a few basic manipulations of one’s worksheet data.
Here we have some sample data (which can be downloaded here) showing changes in amperage over time in response under varying levels of pressures. First let’s plot this data as a waterfall graph by selecting Plot>3D XYY>3D Waterfall.
As you can see from our graph, the rate of change of pressure and amperage is significantly different between the initial and final times that our data is collected. To display the trend across this data series let’s copy the values of our end points, the amperage data for time t=10, and paste it in the y-column of a new worksheet by right-clicking on the first cell and selecting Paste Transpose to set these figures in a single column.
Next enter the corresponding x value of our data and double click on the small black box in the lower right hand corner of the cell to place this value in all rows with preexisting y-data. Add another column to the worksheet, set this as a z column, and repeat the copy/paste transpose step for our pressure values.
With our x, y, and z columns selected, move your cursor to the right edge of these cells until the graph cursor appears, and then drag and drop these values to our waterfall plot. If a prompt appears asking to change the axes values, select “no”. To convert our points to a line, double click one to go into Plot Details and in the Line tab check the Connect Symbols tickbox. Click apply. Before we close out of Plot Details, if the line appears to be going beyond the boundaries of our graph as it does in the below figure, go to the Drop Lines tab and uncheck Parallel to Z Axis.
If we want to add another YZ line across the beginning of our graph, in the Plot Details dialog, let’s first remove the fill below our lines by going to the first plot after Layer1. With this selected, go to the Pattern tab and set the fill color to None. To add the line for our first set of data repeat the previous steps in a new worksheet but instead of using 10, repeat these steps for time t=1. To compare these two lines, simply go back to Plot Details and check the box labelled YZ Projection.
Modify the colors, transparency, and other formatting of your graph, a