Support multiple antenna height

[fgnievinski]

implemented for Fujimura, needs to be done for other algorithms.

main change is positions are returned with coordinate in separate variables.

geo-alhazen.20210929fgn.zip

demo:

e_dom = 1:5:90;
Ha_dom = [10 50 100 200 300 500 1000];
[e_grid, Ha_grid] = meshgrid(e_dom, Ha_dom);

[Di, g, arclen, sldist, xspec, yspec] = get_reflection_spherical (e_grid, Ha_grid);

figure, imagesc(e_dom, Ha_dom, Di)
xlabel('Sat. Elev. (deg.)')
ylabel('Ant. Height (h)')
title('Interf. delay (m)')
grid on
set(gca(), 'YDir','normal')

[vitorhjr]

Is not it better to create grids from the domain inside the function?

[vitorhjr]

I saw that you tried to build a struct of output variables on Fujimura's function. Do you think it is worth?

pos_spec = struct();
pos_spec.X = pos_spec_geo(:,1);
pos_spec.Y = pos_spec_geo(:,2);
pos_spec.x = pos_spec_loc(:,1);
pos_spec.y = pos_spec_loc(:,2);
pos_spec.geo = pos_spec_geo;
pos_spec.loc = pos_spec_loc;

[vitorhjr]

I have released the follow functions:

• get_reflection_spherical
• get_reflection_spherical_fujimura
• get_reflection_spherical_miller
• get_reflection_martinneira
• get_reflection_spherical_helm
• get_reflection_fermat
• get_geocentric_angle

From releases, the following functions were set unused and should be deleted:

• quartic_roots
• z2psi

geo-alhazen-multh_revVitor.zip

[fgnievinski]

Is not it better to create grids from the domain inside the function?

no, because sometimes the user wants just the combinations along the grid diagonal line, instead of the whole grid with all combinations.

[fgnievinski]

I saw that you tried to build a struct of output variables on Fujimura's function. Do you think it is worth?

I contemplated using structures but decided against them because they are difficult to concatenate when comparing results from different algorithms.

[fgnievinski]

I've made the following changes in get_spherical_reflection.m:

• updated documentation in header:
  • copied from github
  • inserted standard first line
  • split optional input
  • noted matrix input
  • added explanatory notes
• applied indentation in code
• created new subfunction for extra results

I've also changed:

• get_spherical_horizon_params, to return coordinates separately
• renamed get_horizon_elevation_angle.m and get_spherical_horizon_params.m, while keeping the old names for backwards compatibility
• created a subfolder to hide internal files from the end user
• made sure demo2 run properly

I've uploaded the new code in a separate branch titled "multh": https://github.com/vitorhjr/geo-alhazen/tree/multh The old main trunk remains available separately: https://github.com/vitorhjr/geo-alhazen/tree/main When we're done, we can merge the branch into the trunk.

Now please do:

• make sure the first demo runs properly
• update the header in get_reflectionspherical*
  • insert standard first line
  • check input/output arguments Download and update the branch only, the trunk is frozen now.

[vitorhjr]

• First demo is running
• Input/output was revised
• Head of function updated
• Other functions get updated in the branch

[vitorhjr]

I've done some changes in the first demo as follow:

• remove the loop of antenna heights;
• change inputs of vectors to matrices of elevation angles and heights

I observed the first demo runs an elevation for each height. The code runs this for each algorithm. For each algorithm loop, only the diagonal elements of the matrix are correct whose we want only results on the spherical horizon.

Currently, the code section of the loop is:

for i=1:n
    Ha = Has(i);
    ehor = ehors(i);
    for j=1:m
        algorithm = algs{j};
        [Di(i,j), g(i,j), arclen(i,j), sldist(i,j), Xspec(i,j),Yspec(i,j)]...
            = get_reflection_spherical (ehor, Ha, [], [], algorithm);
    end
end

I suggest the following:

for i=1:m
    algorithm = algs{i};
    [Di_aux, g_aux, arclen_aux, sldist_aux, Xspec_aux, Yspec_aux]...
            = get_reflection_spherical (e_grid, Ha_grid, [], [], algorithm);

     [Di(:,i), g(:,i), arclen(:,i), sldist(:,i), Xspec(:,i), Yspec(:,i)] ...
         = get_diag(Di_aux, g_aux, arclen_aux, sldist_aux, Xspec_aux, Yspec_aux);
end

Where _getdiag is a local function:

function [Di, g, arclen, sldist, Xspec, Yspec] = get_diag(Di_aux, g_aux, arclen_aux, sldist_aux, Xspec_aux, Yspec_aux)
     Di = diag(Di_aux).'; 
     g = diag(g_aux).';
     arclen= diag(arclen_aux).';
     sldist= diag(sldist_aux).';
     Xspec= diag(Xspec_aux).';
     Yspec= diag(Yspec_aux).';
end

Is it good @fgnievinski?

[fgnievinski]

you can input the diagonal vectors directly:

    for j=1:m
        algorithm = algs{j};
        [Di(i,j), g(i,j), arclen(i,j), sldist(i,j), Xspec(i,j),Yspec(i,j)]...
            = get_reflection_spherical (ehors(:), Has(:), [], [], algorithm);
    end

after all, "matrix input may also be a vector or a scalar": https://github.com/vitorhjr/geo-alhazen/blob/cb7f86693ba571cc95a55e6f1edf1dac1836b60e/get_reflection_spherical.m#L9

[vitorhjr]

You're correct. I thought of the input only as a matrix.

[vitorhjr]

New releases in the first demo on the commit f3a58a1753cb98155cccc08abc42cc94c0420cd1. I've made the following main changes:

• remove the loop of antenna heights;
• inputs column vectors of elevation angle and antenna heights
• include the new function geo-alhazen/get_quasigeo_coord