Every now and then your project may demand a polar bar graph or other similar plots that make use of variable column width. Origin 2016 doesn’t have an included template for this kind of graph but this can easily be accommodated for with some modifications to your standard Polar Theta(x) plot. To follow along with this blog post, you can download the source Origin Project File here. Let’s say we have some data that is organized into angles (col. A) and values (col. B).
We can easily plot this as a polar bar graph by selecting our Y value column and going to Plot>Specialized>Polar theta(X) r(Y), generating a graph that should look like this–
If we still want to display the values of our data without the axes seen above, we’ll need to make use of labels. By default, polar plots don’t allow one to add labels for each point, however this can easily be fixed by clicking on the Line+Symbol button with our graph already selected. Now our graph appears exactly as before, but with squares representing each point of data.
To remove these symbols, let’s double-click on our graph to open the Plot Details dialog, and under the Symbol tab set our symbol size from the default to 0.
The graph should now appear exactly as it did before.
1. Now to rotate our graph and set it to display within the conventional axis values, double click on one of them to open the axis dialog box. From there we will modify our angular axes to be set Clockwise, and set our Axis Start to 90 degrees.
2. Under the Angular Axes Scale menu, let’s set our scale to begin From 0 to 180. Then under the Radial Axes Scale menu change the From value to 0, keeping the To value the same.
3. In order to hide our axes, under the Angular Axes main tab, uncheck the Show Outer Axis tickbox.
In the Angular Axes Grids submenu uncheck Major and Minor Gridlines; then do the same in Radial Axes Grids, and uncheck the Show tickbox in the Outer Axis 1 & 2 sections as well. At this point we should have just a line in our graph window that looks like this–
4. To make this into our offset polar chart, we’ll need to make some changes in the Plot Details dialog. In the Line tab for our series of data change the Connect dropdown from Straight to Step Horz, and then check off the Fill Area Under Curve tickbox. Press Apply, and you should see that your line is now one black wedge shape.
5. To add some colors, first let’s change our line Color from black to an increment list. Selecting the Color dropdown, go to the By Points tab and set Indexing to Col(B). Under the Pattern tab, do the same for the fill color.
Then in the Color List tab, check off the Use custom increment list tickbox, right click on one of the colors and go to the Load Increment List menu. In this example we’ve selected the “Season Spring” increment list.
Lastly, go to the Label tab, and check of the Enable tickbox. Once this has been done, make sure Label Form is set to Y to display the values of each wedge, and then adjust the label size and font formatting accordingly.
Below we see our modified polar graph/pie with values displayed for each section in question. These numbers can be changed to display strings of text or the values in any other column on the active worksheet.
Addendum: Label text that’s too large or too far from the graph itself might get cropped by the boundaries of the graph frame; to rectify this go back into Plot Details dialog; select Layer1 on the left panel; On Display tab, uncheck the Clip Data to Frame tickbox in Data Drawing Options group.