contour_colored: Error with default assignment of levels variable and non-symmetric contour plots

[WaveHello]

Hello,

I was playing around with the

default_gaussian_example

and ran into two errors.

1. Required to be fixed first: The levels is allocated to zero size and not assigned a value. This trickle dows and eventually leads the plots levels to be set to null.
2. For non-origin symmetric contour plots, colored contour lines are plotted but there is no fill between the lines.

Minimal working example is here: wave_gaussian_example.txt. The file extension needs to be changed back to .f90.

Stack and Suggested Change

The problems starts from w_levels being allocated to a zero size array in

subroutine convert_contour_arrays(..)

w_levels (as levels) eventually makes it to

subroutine add_colored_contour_plot_data(plots, plot_count, max_plots, &
                                            x_grid, y_grid, z_grid, levels, &
                                            colormap, show_colorbar, label)
     ...

! NOTE: Suggested change, include size check on levels        
         if (present(levels)) then 
            allocate(plots(plot_count)%contour_levels(size(levels)))
            plots(plot_count)%contour_levels = levels
        else
            call generate_default_contour_levels(plots(plot_count))
        end if

and since it's present and allocated (even though it doesn't have a value) it makes it through

if (present(levels)) then 

and

 plots(plot_count)%contour_levels = levels

ends up being set to nothing.

The minimal change to get it working is to change the if statement to

if (present(levels) .and. size(levels) .gt. 0) then

General Note

I would have made a pull request but I can't figure out how square domains generate levels.

Change Locations

The change to the if statement needs to be made in four subroutines:
1)
subroutine add_contour_plot_data(plots, plot_count, max_plots, colors, x_grid, y_grid, z_grid, levels, label)

subroutine add_colored_contour_plot_data(plots, plot_count, max_plots, x_grid, y_grid, z_grid, levels, colormap, show_colorbar, label)

subroutine add_contour_plot_data(self, x_grid, y_grid, z_grid, levels, label)

 subroutine add_colored_contour_plot_data(self, x_grid, y_grid, z_grid, levels, colormap, show_colorbar, label)

General question

It seems like the oop interface could wrap the functional one, instead of re-implementing the same procedures. Was duplicating the implementation a purposeful design choice or was claude being an overachiever?