Problem with getting an RHI using a specific Azimuth

[GGDLW]

Hello,

I am unsure what I am looking at when I used the following function:

display.plot_rhi(field,vmin=vmin, vmax=vmax, title_flag=False, cmap=cmap)

It appears that it defaulted to an azimuth angle of ~0.5deg.

However, when I tried to specify the azimuth angle with the function plot_azimuth_to_rhi like this:

display.plot_azimuth_to_rhi(field,target_azimuth=90,vmin=vmin, vmax=vmax, title_flag=False, cmap=cmap)

I get the following error:

IndexError: index 15169 is out of bounds for axis 0 with size 14953
Would anyone happen to know a workaround for this error?

[zssherman]

@GGDLW Hello, I think I've seen this before. Can you do a radar.scan_type? I want to see if maybe its picking up something else for the scan

[GGDLW]

Hello,

Here are the results from making a ppi and vpt, respectively:

[zssherman]

@GGDLW Ah ok, so yeah looks like PPI for sure, explains the image in the first plot. The psuedo RHI plot plot_azimuth_to_rhi function you were using above should work, not sure why it threw an index error, do any other azimuths work for the target azimuth?

[GGDLW]

None of the numbers I select (10,15,20,25, ..., 90) have worked for this function. However, when I change the azimuth angle I select, the index seems to increase. For example, when I enter 0 for my azimuth angle, i get an index of 14990, and when I use 15, i get and index of 15019.

[zssherman]

Gotcha, does it show that function failing or is there an underlying function that is popping up thats failing within the plot_azimuth_to_rhi? Trying to pinpoint what the code is failing on in the dataset

[GGDLW]

Here is the error log when I run my script.

Traceback (most recent call last): File "c:\Users\<username>\VSCodeProjects\Python\radar.py", line 57, in <module> display.plot_azimuth_to_rhi(field,target_azimuth=15,vmin=vmin, vmax=vmax, title_flag=False, cmap=cmap) File "C:\Users\<username>\AppData\Local\Programs\Python\Python310\lib\site-packages\pyart\graph\radardisplay.py", line 769, in plot_azimuth_to_rhi data, x, y, z = self._get_azimuth_rhi_data_x_y_z( File "C:\Users\<username>\AppData\Local\Programs\Python\Python310\lib\site-packages\pyart\graph\radardisplay.py", line 1549, in _get_azimuth_rhi_data_x_y_z data = data[prhi_rays] File "C:\Users\<username>\AppData\Local\Programs\Python\Python310\lib\site-packages\numpy\ma\core.py", line 3216, in __getitem__ dout = self.data[indx] IndexError: index 15019 is out of bounds for axis 0 with size 14953

[zssherman]

@GGDLW Can you try setting filter_transitions to false? I'm not entirely sure the cause, it looks like the azimuths its trying to pull has a larger array then the data array. What does radar.azimuth['data'] look like?

[GGDLW]

It looks like setting filter transitions to false resolved the IndexError. However, when I extracted my azimuths, it yielded a (15838,) shape array.

[zssherman]

Ah glad that worked! My guess then is that the radar.antenna_transition array for that data has extra values due to the merging. That's what is checked if filter_transition is True.