PanelArray.show() displays same antenna orientation for different polarization types.

[echacko]

Describe the bug
While plotting the panel array geometry using the PanelArray.show() function, the same antenna array is shown for both polarization type 'VH' and 'cross'. Ideally, the antenna orientation for cross polarization should be rotated by 45 degree w.r.t. polarization type 'VH.

To Reproduce

from sionna.channel.tr38901 import PanelArray

array = PanelArray(num_rows_per_panel = 4,
                   num_cols_per_panel = 4,
                   polarization = 'dual',
                   polarization_type = 'cross',
                   antenna_pattern = '38.901',
                   carrier_frequency = 3.5e9)

array.show()

Expected behavior
The plot when polarization type is set to 'cross' should be as below:

Proposed solution
The markers for antenna, when plotting figure with polarization type 'cross', should be rotated by 45 degrees.
Please find the modified PanelArray.show() function:

def show(self):
    """Show the panel array geometry"""
    marker_vert = MarkerStyle("|")
    marker_horz = MarkerStyle("_")
    if self._polarization == 'dual' and self._polarization_type == 'cross':
        marker_vert = MarkerStyle("|")
        marker_vert._transform.rotate_deg(-45)
        marker_horz = MarkerStyle("_")
        marker_horz._transform.rotate_deg(-45)

    fig = plt.figure()
    pos_pol1 = self._ant_pos_pol1
    plt.plot(pos_pol1[:,1], pos_pol1[:,2], marker = marker_vert,
        markeredgecolor='red', markersize="20", linestyle="None",
        markeredgewidth="2")
    for i, p in enumerate(pos_pol1):
        fig.axes[0].annotate(self._ant_ind_pol1[i].numpy()+1, (p[1], p[2]))
    if self._polarization == 'dual':
        pos_pol2 = self._ant_pos_pol2
        plt.plot(pos_pol2[:,1], pos_pol2[:,2], marker = marker_horz,
            markeredgecolor='black', markersize="20", linestyle="None",
            markeredgewidth="1")
    plt.xlabel("y (m)")
    plt.ylabel("z (m)")
    plt.title("Panel Array")
    plt.legend(["Polarization 1", "Polarization 2"], loc="upper right")

[faycalaa]

Hi,

Thank you for reporting this bug.

We could reproduce the error. The fix you have suggested seems to work fine for dual polarization, but always display vertical polarization for the single polarisation configuration.

Do you want to update your code and make a pull request?

[echacko]

Hi,

The original show() function displays antenna orientation as | irrespective of the polarization type in single polarization configuration.

I will update my code to fix this issue as well and then submit a pull request.

Thanks for pointing out the new error, I did not check with single polarization configuration.

[echacko]

Hi,

I have made the pull request.

Since this was my first pull request, hope I did everything right.

Thanks

[faycalaa]

Thank you.

We will review it and merge it.

[gmarcusm]

Thanks, fixed in 0.9.1