make a contour from a set of points

Hi I am trying to implement from scratch (i.e., without using any library functions for contouring or interpolation ) an iso contour algorithm.

This is my code where i am using pyvista to plot

isovalue = 0.15

def f(x, y):
    return np.sin(10*x)+np.cos(4*y)-np.cos(3*x*y)

x = np.arange(0, 1, 0.05)
y = np.arange(0, 1, 0.05)
XX, YY = np.meshgrid(x, y)
data = f(XX, YY)

def iso_contour(array, target_value):
    contours = []
    rows, cols = array.shape
    # Loop through each cell in the array
    for i in range(rows-1):
        for j in range(cols-1):
            cell_verts = []
            # Check each corner of the cell
            for corner in [(i,j), (i+1,j), (i+1,j+1), (i,j+1)]:
                x, y = corner
                cell_verts.append((x, y, array[x,y]))

                # Check each edge of the cell
            for k in range(4):
                p1, p2 = cell_verts[k], cell_verts[(k+1)%4]
                if (p1[2] >= target_value) != (p2[2] >= target_value):
                    # Calculate intersection point
                    t = (target_value - p1[2]) / (p2[2] - p1[2])
                    x, y = p1[:2] + t * (np.array(p2[:2]) - np.array(p1[:2]))
                    contours.append((y, x, 0.0))
    return contours

contour_points = iso_contour(data, isovalue)
pl = pv.Plotter()
pl.add_mesh(grid, show_edges = True)
for i in range(len(contour_points)-1):
    line = pv.Line(contour_points[i], contour_points[i+1])
    pl.add_mesh(line, color='r', line_width=5)

I wanted to get the contour like this


but i am getting

is there any filter or anything that i can use to make it like contour line !

Thank you !!

you’re looping twice on the same edges.
moreover you will not get lines from joining points which are scanned along x and y.