# Create a Rose Plot Bin That Crosses 0 Degrees in Grapher

A rose diagram has bins that go from 0 to 360. If you need to create a bin that crosses the 0 degree line (for example, suppose you want to create a bin that goes from -15° to +15°), follow the instructions below.
1. Click the File | Open command.
2. Select the data file and click Open. The data will open in the Grapher worksheet.

Original data displayed in worksheet.

1. Highlight the Direction column.
2. Click the Data Tools | Data | Transform command.
3. For the Transform equation, type C=IF(A>345,0,A). This assumes that the direction column is column A and the new blank column is column C. Replace the C and A with the appropriate columns for your data.

Enter the equation to transform all values greater than 345 to 0.

1. Click OK. All values greater than 345 are replaced with 0.
2. Click the Data Tools | Data | Transform command.
3. For the Transform equation, type C=IF(C<0,0,C). This assumes that column C is the new column from Step 5. Replace the C with the appropriate columns for your data

Enter the equation to transform all values less than 0 to 0.

1. Click OK. All values less than 0 are replaced with 0.

Altered data displayed in the worksheet.

1. Click the File | Save command to save the file.
2. Click the File | Close command to close the file and return to the Grapher plot window.

Back in the Grapher plot window, create a new rose plot.

1. Click the Home | New Graph | Polar | Polar Rose Chart command.
2. Select the data file edited above and click Open.
3. Click on the plot in the Object Manager to select it.
4. In the Property Manager, click on the Plot tab.
5. Set the Direction column or Data variable column to the transformed column above, Column C.
6. Set the Bar width bins type field to Custom bins.
7. Click the Edit button next to Bins.
8. Set the first bin to have a Minimum (>): value of -15.
9. Adjust any other bin values and click OK.

The first bin will cross the zero line, displaying the desired data.

Updated May 2023