I’m working with a 3D dataset in Python where some (x,y) points create frame-like structures, some of them with multiple z-values per (x,y) pair, which seems to lead to a problem with griddata. The provided code produces the interpolation between 2 data sets as a working example, and then tries to interpolate 2 data sets, where one has multiple z values. The data and the interpolation are plotted for each case. I also provide an image with a marking, what seems to create the problem afaik. How can I interpolate such data with griddata or is there another way?  Code contains part of the original (simulation) data. import numpy as np import matplotlib.pyplot as plt from scipy.spatial import distance from scipy.interpolate import griddata from scipy.ndimage import gaussian_filter from mpl_toolkits.mplot3d.art3d import Poly3DCollection from matplotlib.colors import Normalize from matplotlib import cm import matplotlib.tri as mtri from scipy.interpolate import LinearNDInterpolator x1 = np.array([ 0, 0.08317108166803, 0.16393703317322, 0.24010197356808, 0.31189968667059, 0.37964309047995, 0.44362962064596, 0.50416941327588, 0.56154833462750, 0.61603270573008, 0.66785467575344, 0.71722870327800, 0.76434124363645, 0.80936126105512, 0.85243882934910, 0.89371020366228, 0.93330023252176, 0.97132031393031, 1.0078733278234, 1.04305186588065, 1.07694164659622, 1.10962198351184, 1.14116475234496, 1.17163490787683, 1.20109277181813, 1.22959493653164, 1.25719327772516, 1.28393541084346, 1.30986533211137, 1.33502459428484, 1.3594517119059, 1.38318253432743, 1.40625054167016, 1.428687092237, 1.45052182005806, 1.47178239513572, 1.4924946731886, 1.51268282564772, 1.53236959683959, 1.55157657215197, 1.5703240685486, 1.58863120287582, 1.60651600994447, 1.62399550071956, 1.64108576853907, 1.65780207082065, 1.67415889980995, 1.69017008507776, 1.70584884180465, 1.72120783285127, 1.73625905724844, 1.75101389043042, 1.76548311976239, 1.77967698639756, 1.79360519288652, 1.80727689980216, 1.8207008202846, 1.83388518878035, 1.84683777315861, 1.85956584789141, 1.87207616663999, 1.88437496210868, 1.89646789288332, 1.90835992552183, 1.92005539714572, 1.9315578245162, 1.94286977773435, 1.95399269320514, 1.96492669014037, 1.97567031873621, 1.98622026624029, 1.99657105652974, 2.00671480587649, 2.01664080378909, 2.02633512036696, 2.03578034488985, 2.04495553215686, 2.05383630364206, 2.0623951776226, 2.0706018164916, 2.07842481734728, 2.0858329876037, 2.09279775917234, 2.09929633971377, 2.10531538227125, 2.11085508513429, 2.11593338459342, 2.12058937638755, 2.12488319044411, 2.12889284005344, 2.13270923022591, 2.13642524129613 ]) z1 = np.array([ 28.6619989743589, 28.6049608580482, 28.5450559014246, 28.4794835365082, 28.4092022241029, 28.3350387336261, 28.2576380039013, 28.1775367384564, 28.0951654495223, 28.0108638015799, 27.9249204615456, 27.8375597971889, 27.7489735572062, 27.6593178994861, 27.5687237423079, 27.4773041964674, 27.385152945665, 27.2923533725037, 27.1989741902862, 27.1050785554844, 27.0107190614389, 26.9159392616942, 26.8207798998579, 26.7252795524418, 26.6294706791138, 26.5333790187747, 26.4370286448011, 26.3404423792824, 26.2436415876413, 26.1466433615791, 26.0494627200553, 25.9521139974702, 25.8546109832136, 25.7569659319296, 25.6591888403289, 25.5612891089313, 25.4632757574251, 25.3651575801692, 25.2669423848755, 25.168636129068, 25.0702443614344, 24.9717723691753, 24.8732252294088, 24.7746078436806, 24.6759249761952, 24.5771812831842, 24.4783811991822, 24.3795278208977, 24.2806239242195, 24.1816722476486, 24.082675412506, 23.9836359405196, 23.8845562687947, 23.7854387639056, 23.6862857298263, 23.5870993764416, 23.4878813512533, 23.3886330916743, 23.2893560024275, 23.1900514136945, 23.0907205842034, 22.9913647072391, 22.8919849096176, 22.792582243255, 22.6931576855678, 22.5937118769204, 22.4942453558146, 22.3947585791552, 22.2952518558259, 22.1957253129467, 22.0961789025235, 21.9966124171542, 21.8970253898987, 21.7974170708687, 21.6977864181452, 21.5981324310853, 21.4984538542985, 21.398749114135, 21.2990163991982, 21.1992542481573, 21.0994617682189, 20.9996381351822, 20.8997827371874, 20.799896002592, 20.6999792732694, 20.6000347502029, 20.5000657435458, 20.4000764848403, 20.3000713432661, 20.2000540343164, 20.1000287433225, 20 ]) y1 = np.full(len(x1),1) x2 = np.array([ 0, 0.09970480868419, 0.19934990930324, 0.29892560671855, 0.39845053029212, 0.49791294847979, 0.59729126792395, 0.69654894215390, 0.79562230931157, 0.89441829468223, 0.99278184799703, 1.09041596346573, 1.18680564093363, 1.2811247216627, 1.37173821384615, 1.45615592046124, 1.53140709459726, 1.59481447147833, 1.64540118865725, 1.68420020117436, 1.7139567901805, 1.73739377080012, 1.75669514508293, 1.77341533375185, 1.78855241978336, 1.80270054725639, 1.81619925811863, 1.82923458834867, 1.84190868011591, 1.8542787909028, 1.86637895717989, 1.87823123253782, 1.8898513429009, 1.90125155489232, 1.91244211394041, 1.92343198232874, 1.93422925599876, 1.94484137307261, 1.95527523060825, 1.96553726952681, 1.97563352932633, 1.98556968830044, 1.99535109412568, 2.00498278811171, 2.01446952528177, 2.02381579222306, 2.03302582656997, 2.04210365316528, 2.05105308938297, 2.05987776623044, 2.06858114998522, 2.07716655334668, 2.08563714669058, 2.09399597192344, 2.1022459544216, 2.11038991079032, 2.11843055346434, 2.12637049464471, 2.13421224945851, 2.14195824744614, 2.14961083302462, 2.15717226465044, 2.16464472287464, 2.17203031834828, 2.17933109740207, 2.18654904729014, 2.19368610417827, 2.20074416242255, 2.20772507771543, 2.21463066429355, 2.2214626950629, 2.22822290393084, 2.23491298448034, 2.24153458547506, 2.24808930743357, 2.25457870003345, 2.26100425466765, 2.26736739519304, 2.27366947406393, 2.27991176845626, 2.28609547194039, 2.29222169050455, 2.29829141992375, 2.30430552303668, 2.31026470050494, 2.31616945318094, 2.32202003758885, 2.32781640900641, 2.33355814983544, 2.33924438051412, 2.3448736508916, 2.35044381228348, 2.3559518778997, 2.36139385612463, 2.36676455738366, 2.37205741259143, 2.37726426201264, 2.38237517331566, 2.38737831946074, 2.39225993069978, 2.39700436076639, 2.40159431859356, 2.40601130725183, 2.41023630806784, 2.4142507588751, 2.418037990112, 2.42158487083293, 2.42488372545427, 2.42793436504128, 2.43074593332474, 2.4333379706335, 2.43574001568792, 2.4379889754186, 2.44012113735539, 2.44214574160271 ]) z2 = np.array([ 30.0078688964104, 30.0065512265173, 30.0029356360187, 29.9976735322442, 29.9915262693748, 29.9844424862537, 29.9762659464609, 29.9667364364951, 29.9554600427241, 29.9419800400481, 29.9256478232344, 29.9054159211507, 29.8799561681087, 29.8476996253689, 29.8061730864421, 29.7532731986494, 29.6880451094337, 29.6112448542866, 29.5253946922475, 29.4335819554567, 29.3384411867613, 29.2415312959595, 29.1437049711797, 29.04539962879, 28.9468401079325, 28.8481308935213, 28.7493306654707, 28.6504694225423, 28.5515612207417, 28.4526148172972, 28.3536354145385, 28.2546261943038, 28.1555895272291, 28.0565273761794, 27.9574414945533, 27.8583335076939, 27.7592047062979, 27.6600561309973, 27.5608887508238, 27.4617034796921, 27.3625011864055, 27.2632827022544, 27.1640488269094, 27.0648003331593, 26.9655379708194, 26.866262470073, 26.7669745291472, 26.6676746328858, 26.5683632230419, 26.4690407437848, 26.3697076224236, 26.2703642715209, 26.171011090825, 26.0716484692661, 25.9722767866544, 25.8728964148864, 25.7735077188227, 25.6741110570318, 25.5747068020388, 25.4752952472731, 25.3758766209457, 25.2764511425401, 25.1770190239312, 25.077580470411, 24.978135681488, 24.8786848515835, 24.7792281708969, 24.6797658262875, 24.5802980016905, 24.4808248780774, 24.381346633632, 24.2818634440495, 24.1823754825859, 24.0828829198801, 23.9833859238618, 23.8838846597107, 23.7843792895138, 23.6848699718101, 23.5853568615186, 23.4858401098541, 23.3863198605794, 23.2867961336504, 23.1872689742316, 23.0877384678003, 22.9882046876333, 22.8886676931036, 22.7891275276662, 22.6895842161987, 22.5900377616683, 22.4904881410033, 22.3909353002525, 22.2913791491932, 22.1918194461756, 22.0922558825952, 21.9926883788735, 21.8931167722048, 21.7935407990426, 21.6939600883707, 21.5943741599893, 21.4947824294466, 21.395184222527, 21.2955788018895, 21.1959654064542, 21.0963434196656, 20.9967131851386, 20.8970742537356, 20.7974262724062, 20.6977693400472, 20.5981040167542, 20.4984312619284, 20.3987523065558, 20.2990684973495, 20.1993811617366, 20.099691467103, 20 ]) y2 = np.full(len(x2),2) x3 = np.array([ 0, 0.106091997247487, 0.212282862868987, 0.318600341722176, 0.425123104761527, 0.531901352872626, 0.638980673349671, 0.746408888895399, 0.85423835573243, 0.962522013543275, 1.07131093710695, 1.18064439993891, 1.29054534660613, 1.40102082494537, 1.51205952335725, 1.62363164712265, 1.73568405272677, 1.84814589283292, 1.96093277164309, 2.07395098084042, 2.18706544796369, 2.30006049798178, 2.41251892919309, 2.52351045392648, 2.63096976610101, 2.73100121086301, 2.77148016441521, 2.78453458174498, 2.79186010794094, 2.79751816975908, 2.80236248394865, 2.80670132496914, 2.81067659404222, 2.81436810315714, 2.81782835677761, 2.81838473210957, 2.82109652791738, 2.82420427153188, 2.82717868109766, 2.83004342751941, 2.83281945446213, 2.83552519787279, 2.83817680575457, 2.84078819902162, 2.84337124785453, 2.84593589783908, 2.84849035993836, 2.85104128587469, 2.85359396537556, 2.85615250287907, 2.85872000627528, 2.86129873724824, 2.86389026304064, 2.86649557135293, 2.86911518641933, 2.8717492484006, 2.87439759958004, 2.87705983816952, 2.87973537526801, 2.88242347197052, 2.88512327706806, 2.88783385231766, 2.88845703622116, 2.89055419723002, 2.89328326484414, 2.89601997738632, 2.89876323695298, 2.90151193463858, 2.90426495815636, 2.90702119863042, 2.90977955571619, 2.91253894330014, 2.91529829288703, 2.91805655711182, 2.92081271230053, 2.92356576021251, 2.92631472933472, 2.92905867580467, 2.93179668334584, 2.93452786251032, 2.93725134958514, 2.93965292016822, 2.93996630533669, 2.94267191310587, 2.94536737736262, 2.94805192150669, 2.95072478659992, 2.95338522921948, 2.9560325199586, 2.95866594104728, 2.96128478419988, 2.96388834746919, 2.96647593163284, 2.96904683568692, 2.97160035145282, 2.97413575724706, 2.97425125556441, 2.97665231021929, 2.97914923756346, 2.98162572566976, 2.98408090824307, 2.98651385151949, 2.98892353757412, 2.99130884415201, 2.99366851923393, 2.99600114768388, 2.9962606601005, 2.99830510879971, 3.00057851901249, 3.00281914620488, 3.00502428120326, 3.00719053828585, 3.00931351650196, 3.00952011645174, 3.01138721018009, 3.0134029388599, 3.01534737564675, 3.01699921085196, 3.01719889804888, 3.01892089400833, 3.02044973125651, 3.02078939388317, 3.02167377283328, 3.02228920892799, 3.02239824880744 ]) z3 = np.array([ 30.1186241174416, 30.1184849219899, 30.1171034471136, 30.1152951272103, 30.1133655615441, 30.1113195993005, 30.1091433108655, 30.1068210776114, 30.1043270725803, 30.1016326866963, 30.0986949871154, 30.095463219881, 30.091866695563, 30.087823561571, 30.0832240264785, 30.0779411584852, 30.0718042824719, 30.064598064254, 30.0560271138372, 30.0456642379577, 30.0328664792409, 30.0166381634173, 29.995383512023, 29.9666311419869, 29.9269062544625, 29.8724446142301, 20, 20.0992866487574, 20.1987778658839, 20.2983155533319, 20.3978803414887, 20.4974615256815, 20.5970538814448, 20.6966543922422, 20.796260963899, 29.8010645620936, 20.8958720196992, 20.9954865830927, 21.0951039613303, 21.1947236485541, 21.2943452750121, 21.3939685837807, 21.493593496968, 21.5932201164118, 21.6928485704969, 21.7924790313127, 21.8921116969745, 21.9917467869875, 22.0913845424964, 22.1910252330904, 22.2906691240923, 22.3903164843267, 22.4899675841224, 22.5896226941457, 22.6892820856006, 22.7889460266206, 22.888614783746, 22.988288620861, 23.0879678014928, 23.1876525873797, 23.287343240002, 23.3870400197103, 29.7142868959217, 23.486743187404, 23.5864530033367, 23.6861697290352, 23.7858936263979, 23.885624958565, 23.9853639878029, 24.0851109788725, 24.1848661985415, 24.2846299172733, 24.3844024085183, 24.4841839497909, 24.5839748236319, 24.6837753181654, 24.7835857287758, 24.8834063591202, 24.9832375223667, 25.0830795430067, 25.1829327578276, 29.6171448515155, 25.2827975190689, 25.3826741941813, 25.4825631716602, 25.5824648589361, 25.6823796912861, 25.7823081276471, 25.8822506637417, 25.9822078278468, 26.0821801933113, 26.1821683788585, 26.2821730607998, 26.3821949758609, 26.482234934283, 26.5822938276285, 29.5148759694037, 26.6823726493158, 26.7824724970099, 26.8825946040959, 26.9827403478161, 27.0829112850487, 27.1831091758242, 27.283336026885, 27.3835941282532, 27.4838861281617, 29.4108704451581, 27.5842150845333, 27.6845846449453, 27.7849990464475, 27.8854632367103, 27.9859831360428, 28.0865659498792, 29.3067361736195, 28.1872205245328, 28.2879579643369, 28.3887923780716, 29.2030641097122, 28.4897421297855, 28.5908314496745, 28.6920929845482, 29.0999759013086, 28.7935707828626, 28.997430828688, 28.8953250739844 ]) y3 = np.full(len(x3),3) def filter_data_by_indices(data, indices_to_keep): # Convert 1-based indices to 0-based indices for Python indexing indices_to_keep = [i - 1 for i in indices_to_keep] # Filter the data by the specified indices filtered_data = [data[i] for i in indices_to_keep if 0 <= i < len(data)] return filtered_data def mirror_data(data): mirrored_data = [] for x,y,z in data: # Combine positive and negative r values x_combined = np.concatenate([-x[::-1], x]) z_combined = np.concatenate( [z[::-1], z ])-20 #offset of sim raw data y_combined = np.full_like(x_combined, y[0]) mirrored_data.append((x_combined, y_combined, z_combined)) return mirrored_data def nearest_neighbor_sort(data): sorted_data = [] for x, y, z in data: # Stack x and z to form (x, z) pairs xz_pairs = np.column_stack((x, z)) # Nearest neighbor sorting sorted_indices = [0] # Start with the first point remaining_indices = list(range(1, len(xz_pairs))) while remaining_indices: last_index = sorted_indices[-1] distances = [ distance.euclidean(xz_pairs[last_index], xz_pairs[i]) for i in remaining_indices ] nearest_index = remaining_indices[np.argmin(distances)] sorted_indices.append(nearest_index) remaining_indices.remove(nearest_index) # Apply the sorted indices to x and z, y remains unchanged x_sorted = x[sorted_indices] z_sorted = z[sorted_indices] sorted_data.append((x_sorted, y, z_sorted)) return sorted_data def plot_data(filtered_data): fig = plt.figure() ax = fig.add_subplot(111, projection='3d') all_x, all_y, all_z = [], [], [] for x, y, z in filtered_data: # log_t = np.log10(t) all_x.extend(x) all_y.extend(y) all_z.extend(z) ax.plot(x, y, z, color='black', alpha=0.8, linewidth=1.5) plt.show() # Interpolate surface X, Y, Z = interpolate_surface(all_x, all_y, all_z) X_flat, Y_flat, Z_flat = X.flatten(), Y.flatten(), Z.flatten() triangles = mtri.Triangulation(X_flat, Y_flat) norm = Normalize(vmin=min(Y_flat), vmax=max(Y_flat)) cmap = cm.gnuplot colors = cmap(norm(Y_flat)) fig = plt.figure() ax = fig.add_subplot(111, projection='3d') # Build Poly3DCollection poly3d = [] for tri in triangles.triangles: poly3d.append([(X_flat[tri[0]], Y_flat[tri[0]], Z_flat[tri[0]]), (X_flat[tri[1]], Y_flat[tri[1]], Z_flat[tri[1]]), (X_flat[tri[2]], Y_flat[tri[2]], Z_flat[tri[2]])]) poly_collection = Poly3DCollection(poly3d, facecolors=colors[triangles.triangles].mean(axis=1), edgecolors='black', linewidths=0.06, alpha=1) ax.add_collection3d(poly_collection) plt.show() def interpolate_surface(all_r, all_log_t, all_z, num_points=100, sigma=1): r_vals = np.linspace(min(all_r), max(all_r), num_points) t_vals = np.linspace(min(all_log_t), max(all_log_t), num_points) R, T = np.meshgrid(r_vals, t_vals) points = np.vstack((all_r, all_log_t)).T values = np.array(all_z) Z = griddata(points, values, (R, T), method='linear') # 'cubic' or 'nearest' ## Interpolate the data with linearNDInterpolator # interpolator = LinearNDInterpolator(points, values) # Z = interpolator(np.array([R.flatten(), T.flatten()]).T).reshape(R.shape) Z = np.nan_to_num(Z, nan=0) # Z = gaussian_filter(Z, sigma=sigma) return R, T, Z data = [(x1,y1,z1),(x2,y2,z2),(x3,y3,z3)] # plot first 2 data sets filtered_data = filter_data_by_indices(data, [1,2]) sorted_data = nearest_neighbor_sort(filtered_data) mirrored_data = mirror_data(sorted_data) plot_data(mirrored_data) # plot last 2 data sets (here interpolation is wrong) filtered_data = filter_data_by_indices(data, [2,3]) sorted_data = nearest_neighbor_sort(filtered_data) mirrored_data = mirror_data(sorted_data) plot_data(mirrored_data) 
Don't interpolate in a rectilinear parameter space. Instead, you need to  Transform to a semipolar (cylindrical) coordinate space with y as linear, and xz radius and xz angle as the other axes. If I had to guess a safe x-z origin, it would be (0, 0). Interpolate on that. Prior to graphing, transform back to xyz.  This is the safest "dumb" solution that will fit your data. If your data have a different hidden parameter space that produce unique, somewhat uniform dependent coordinates then you should use that instead. I also don't understand you're making your own triangle mesh. It causes problems even with a well-parameterized dataset. Just use plot_surface instead: import typing import matplotlib import numpy as np import matplotlib.pyplot as plt import scipy from scipy.spatial.distance import euclidean from mpl_toolkits.mplot3d.art3d import Poly3DCollection def mirror_data( data: list[tuple[np.ndarray, np.ndarray, np.ndarray]], ) -> list[np.ndarray]: mirrored_data = [] for x, y, z in data: # Combine positive and negative r values x_combined = np.concatenate([-x[::-1], x]) z_combined = np.concatenate([z[::-1], z]) - 20 # offset of sim raw data y_combined = np.full_like(x_combined, y[0]) mirrored_data.append(np.array((x_combined, y_combined, z_combined))) return mirrored_data def nearest_neighbor_sort(data: typing.Sequence[np.ndarray]) -> list[np.ndarray]: sorted_data = [] for x, y, z in data: # Stack x and z to form (x, z) pairs xz_pairs = np.column_stack((x, z)) # Nearest neighbor sorting sorted_indices = [0] # Start with the first point remaining_indices = list(range(1, len(xz_pairs))) while remaining_indices: last_index = sorted_indices[-1] distances = [ euclidean(xz_pairs[last_index], xz_pairs[i]) for i in remaining_indices ] nearest_index = remaining_indices[np.argmin(distances)] sorted_indices.append(nearest_index) remaining_indices.remove(nearest_index) # Apply the sorted indices to x and z, y remains unchanged x_sorted = x[sorted_indices] z_sorted = z[sorted_indices] sorted_data.append(np.array((x_sorted, y, z_sorted))) return sorted_data def plot_data(filtered_data: list[np.ndarray]) -> None: fig, ax = plt.subplots(subplot_kw={'projection': '3d'}) ax.set_xlabel('R') ax.set_ylabel('T') ax.set_zlabel('Z') all_x, all_y, all_z = np.concatenate(filtered_data, axis=-1) for x, y, z in filtered_data: # log_t = np.log10(t) ax.plot(x, y, z, color='black', alpha=0.8, linewidth=1.5) # Interpolate surface X, Y, Z = interpolate_surface(all_x, all_y, all_z, num_points=50) fig, ax = plt.subplots(subplot_kw={'projection': '3d'}) ax.set_xlabel('R') ax.set_ylabel('T') ax.set_zlabel('Z') ax.plot_surface(X, Y, Z, cmap=matplotlib.cm.plasma) def interpolate_surface( all_r: np.ndarray, all_log_t: np.ndarray, all_z: np.ndarray, num_points: int = 100, sigma: float = 1., gaussian: bool = False, ) -> tuple[ np.ndarray, # R np.ndarray, # T np.ndarray, # Z ]: # r_vals = np.linspace(all_r.min(), all_r.max(), num_points) t_vals = np.linspace(all_log_t.min(), all_log_t.max(), num_points) phi_vals = np.linspace(0, np.pi, num_points) P, T = np.meshgrid(phi_vals, t_vals) # t is kept as linear. Transform r,z to a cylindrical system. rmax = np.abs(all_r).max() zmax = np.abs(all_z).max() rscale = all_r/rmax zscale = all_z/zmax radius = np.hypot(zscale, rscale) angle = np.atan2(zscale, rscale) points = np.stack((angle, all_log_t), axis=-1) grid_radius = scipy.interpolate.griddata(points, radius, (P, T), method='linear') # 'cubic' or 'nearest' if gaussian: grid_radius = scipy.ndimage.gaussian_filter(grid_radius, sigma=sigma) # Transform from cylindrical angle (P), T, grid_radius to R, T, Z R = rmax * grid_radius * np.cos(P) Z = zmax * grid_radius * np.sin(P) return R, T, Z def demo() -> None: x1 = np.array(( 0, 0.08317108166803, 0.16393703317322, 0.24010197356808, 0.31189968667059, 0.37964309047995, 0.44362962064596, 0.50416941327588, 0.56154833462750, 0.61603270573008, 0.66785467575344, 0.71722870327800, 0.76434124363645, 0.80936126105512, 0.85243882934910, 0.89371020366228, 0.93330023252176, 0.97132031393031, 1.0078733278234, 1.04305186588065, 1.07694164659622, 1.10962198351184, 1.14116475234496, 1.17163490787683, 1.20109277181813, 1.22959493653164, 1.25719327772516, 1.28393541084346, 1.30986533211137, 1.33502459428484, 1.3594517119059, 1.38318253432743, 1.40625054167016, 1.428687092237, 1.45052182005806, 1.47178239513572, 1.4924946731886, 1.51268282564772, 1.53236959683959, 1.55157657215197, 1.5703240685486, 1.58863120287582, 1.60651600994447, 1.62399550071956, 1.64108576853907, 1.65780207082065, 1.67415889980995, 1.69017008507776, 1.70584884180465, 1.72120783285127, 1.73625905724844, 1.75101389043042, 1.76548311976239, 1.77967698639756, 1.79360519288652, 1.80727689980216, 1.8207008202846, 1.83388518878035, 1.84683777315861, 1.85956584789141, 1.87207616663999, 1.88437496210868, 1.89646789288332, 1.90835992552183, 1.92005539714572, 1.9315578245162, 1.94286977773435, 1.95399269320514, 1.96492669014037, 1.97567031873621, 1.98622026624029, 1.99657105652974, 2.00671480587649, 2.01664080378909, 2.02633512036696, 2.03578034488985, 2.04495553215686, 2.05383630364206, 2.0623951776226, 2.0706018164916, 2.07842481734728, 2.0858329876037, 2.09279775917234, 2.09929633971377, 2.10531538227125, 2.11085508513429, 2.11593338459342, 2.12058937638755, 2.12488319044411, 2.12889284005344, 2.13270923022591, 2.13642524129613 )) z1 = np.array(( 28.6619989743589, 28.6049608580482, 28.5450559014246, 28.4794835365082, 28.4092022241029, 28.3350387336261, 28.2576380039013, 28.1775367384564, 28.0951654495223, 28.0108638015799, 27.9249204615456, 27.8375597971889, 27.7489735572062, 27.6593178994861, 27.5687237423079, 27.4773041964674, 27.385152945665, 27.2923533725037, 27.1989741902862, 27.1050785554844, 27.0107190614389, 26.9159392616942, 26.8207798998579, 26.7252795524418, 26.6294706791138, 26.5333790187747, 26.4370286448011, 26.3404423792824, 26.2436415876413, 26.1466433615791, 26.0494627200553, 25.9521139974702, 25.8546109832136, 25.7569659319296, 25.6591888403289, 25.5612891089313, 25.4632757574251, 25.3651575801692, 25.2669423848755, 25.168636129068, 25.0702443614344, 24.9717723691753, 24.8732252294088, 24.7746078436806, 24.6759249761952, 24.5771812831842, 24.4783811991822, 24.3795278208977, 24.2806239242195, 24.1816722476486, 24.082675412506, 23.9836359405196, 23.8845562687947, 23.7854387639056, 23.6862857298263, 23.5870993764416, 23.4878813512533, 23.3886330916743, 23.2893560024275, 23.1900514136945, 23.0907205842034, 22.9913647072391, 22.8919849096176, 22.792582243255, 22.6931576855678, 22.5937118769204, 22.4942453558146, 22.3947585791552, 22.2952518558259, 22.1957253129467, 22.0961789025235, 21.9966124171542, 21.8970253898987, 21.7974170708687, 21.6977864181452, 21.5981324310853, 21.4984538542985, 21.398749114135, 21.2990163991982, 21.1992542481573, 21.0994617682189, 20.9996381351822, 20.8997827371874, 20.799896002592, 20.6999792732694, 20.6000347502029, 20.5000657435458, 20.4000764848403, 20.3000713432661, 20.2000540343164, 20.1000287433225, 20 )) x2 = np.array(( 0, 0.09970480868419, 0.19934990930324, 0.29892560671855, 0.39845053029212, 0.49791294847979, 0.59729126792395, 0.69654894215390, 0.79562230931157, 0.89441829468223, 0.99278184799703, 1.09041596346573, 1.18680564093363, 1.2811247216627, 1.37173821384615, 1.45615592046124, 1.53140709459726, 1.59481447147833, 1.64540118865725, 1.68420020117436, 1.7139567901805, 1.73739377080012, 1.75669514508293, 1.77341533375185, 1.78855241978336, 1.80270054725639, 1.81619925811863, 1.82923458834867, 1.84190868011591, 1.8542787909028, 1.86637895717989, 1.87823123253782, 1.8898513429009, 1.90125155489232, 1.91244211394041, 1.92343198232874, 1.93422925599876, 1.94484137307261, 1.95527523060825, 1.96553726952681, 1.97563352932633, 1.98556968830044, 1.99535109412568, 2.00498278811171, 2.01446952528177, 2.02381579222306, 2.03302582656997, 2.04210365316528, 2.05105308938297, 2.05987776623044, 2.06858114998522, 2.07716655334668, 2.08563714669058, 2.09399597192344, 2.1022459544216, 2.11038991079032, 2.11843055346434, 2.12637049464471, 2.13421224945851, 2.14195824744614, 2.14961083302462, 2.15717226465044, 2.16464472287464, 2.17203031834828, 2.17933109740207, 2.18654904729014, 2.19368610417827, 2.20074416242255, 2.20772507771543, 2.21463066429355, 2.2214626950629, 2.22822290393084, 2.23491298448034, 2.24153458547506, 2.24808930743357, 2.25457870003345, 2.26100425466765, 2.26736739519304, 2.27366947406393, 2.27991176845626, 2.28609547194039, 2.29222169050455, 2.29829141992375, 2.30430552303668, 2.31026470050494, 2.31616945318094, 2.32202003758885, 2.32781640900641, 2.33355814983544, 2.33924438051412, 2.3448736508916, 2.35044381228348, 2.3559518778997, 2.36139385612463, 2.36676455738366, 2.37205741259143, 2.37726426201264, 2.38237517331566, 2.38737831946074, 2.39225993069978, 2.39700436076639, 2.40159431859356, 2.40601130725183, 2.41023630806784, 2.4142507588751, 2.418037990112, 2.42158487083293, 2.42488372545427, 2.42793436504128, 2.43074593332474, 2.4333379706335, 2.43574001568792, 2.4379889754186, 2.44012113735539, 2.44214574160271 )) z2 = np.array(( 30.0078688964104, 30.0065512265173, 30.0029356360187, 29.9976735322442, 29.9915262693748, 29.9844424862537, 29.9762659464609, 29.9667364364951, 29.9554600427241, 29.9419800400481, 29.9256478232344, 29.9054159211507, 29.8799561681087, 29.8476996253689, 29.8061730864421, 29.7532731986494, 29.6880451094337, 29.6112448542866, 29.5253946922475, 29.4335819554567, 29.3384411867613, 29.2415312959595, 29.1437049711797, 29.04539962879, 28.9468401079325, 28.8481308935213, 28.7493306654707, 28.6504694225423, 28.5515612207417, 28.4526148172972, 28.3536354145385, 28.2546261943038, 28.1555895272291, 28.0565273761794, 27.9574414945533, 27.8583335076939, 27.7592047062979, 27.6600561309973, 27.5608887508238, 27.4617034796921, 27.3625011864055, 27.2632827022544, 27.1640488269094, 27.0648003331593, 26.9655379708194, 26.866262470073, 26.7669745291472, 26.6676746328858, 26.5683632230419, 26.4690407437848, 26.3697076224236, 26.2703642715209, 26.171011090825, 26.0716484692661, 25.9722767866544, 25.8728964148864, 25.7735077188227, 25.6741110570318, 25.5747068020388, 25.4752952472731, 25.3758766209457, 25.2764511425401, 25.1770190239312, 25.077580470411, 24.978135681488, 24.8786848515835, 24.7792281708969, 24.6797658262875, 24.5802980016905, 24.4808248780774, 24.381346633632, 24.2818634440495, 24.1823754825859, 24.0828829198801, 23.9833859238618, 23.8838846597107, 23.7843792895138, 23.6848699718101, 23.5853568615186, 23.4858401098541, 23.3863198605794, 23.2867961336504, 23.1872689742316, 23.0877384678003, 22.9882046876333, 22.8886676931036, 22.7891275276662, 22.6895842161987, 22.5900377616683, 22.4904881410033, 22.3909353002525, 22.2913791491932, 22.1918194461756, 22.0922558825952, 21.9926883788735, 21.8931167722048, 21.7935407990426, 21.6939600883707, 21.5943741599893, 21.4947824294466, 21.395184222527, 21.2955788018895, 21.1959654064542, 21.0963434196656, 20.9967131851386, 20.8970742537356, 20.7974262724062, 20.6977693400472, 20.5981040167542, 20.4984312619284, 20.3987523065558, 20.2990684973495, 20.1993811617366, 20.099691467103, 20 )) x3 = np.array(( 0, 0.106091997247487, 0.212282862868987, 0.318600341722176, 0.425123104761527, 0.531901352872626, 0.638980673349671, 0.746408888895399, 0.85423835573243, 0.962522013543275, 1.07131093710695, 1.18064439993891, 1.29054534660613, 1.40102082494537, 1.51205952335725, 1.62363164712265, 1.73568405272677, 1.84814589283292, 1.96093277164309, 2.07395098084042, 2.18706544796369, 2.30006049798178, 2.41251892919309, 2.52351045392648, 2.63096976610101, 2.73100121086301, 2.77148016441521, 2.78453458174498, 2.79186010794094, 2.79751816975908, 2.80236248394865, 2.80670132496914, 2.81067659404222, 2.81436810315714, 2.81782835677761, 2.81838473210957, 2.82109652791738, 2.82420427153188, 2.82717868109766, 2.83004342751941, 2.83281945446213, 2.83552519787279, 2.83817680575457, 2.84078819902162, 2.84337124785453, 2.84593589783908, 2.84849035993836, 2.85104128587469, 2.85359396537556, 2.85615250287907, 2.85872000627528, 2.86129873724824, 2.86389026304064, 2.86649557135293, 2.86911518641933, 2.8717492484006, 2.87439759958004, 2.87705983816952, 2.87973537526801, 2.88242347197052, 2.88512327706806, 2.88783385231766, 2.88845703622116, 2.89055419723002, 2.89328326484414, 2.89601997738632, 2.89876323695298, 2.90151193463858, 2.90426495815636, 2.90702119863042, 2.90977955571619, 2.91253894330014, 2.91529829288703, 2.91805655711182, 2.92081271230053, 2.92356576021251, 2.92631472933472, 2.92905867580467, 2.93179668334584, 2.93452786251032, 2.93725134958514, 2.93965292016822, 2.93996630533669, 2.94267191310587, 2.94536737736262, 2.94805192150669, 2.95072478659992, 2.95338522921948, 2.9560325199586, 2.95866594104728, 2.96128478419988, 2.96388834746919, 2.96647593163284, 2.96904683568692, 2.97160035145282, 2.97413575724706, 2.97425125556441, 2.97665231021929, 2.97914923756346, 2.98162572566976, 2.98408090824307, 2.98651385151949, 2.98892353757412, 2.99130884415201, 2.99366851923393, 2.99600114768388, 2.9962606601005, 2.99830510879971, 3.00057851901249, 3.00281914620488, 3.00502428120326, 3.00719053828585, 3.00931351650196, 3.00952011645174, 3.01138721018009, 3.0134029388599, 3.01534737564675, 3.01699921085196, 3.01719889804888, 3.01892089400833, 3.02044973125651, 3.02078939388317, 3.02167377283328, 3.02228920892799, 3.02239824880744 )) z3 = np.array(( 30.1186241174416, 30.1184849219899, 30.1171034471136, 30.1152951272103, 30.1133655615441, 30.1113195993005, 30.1091433108655, 30.1068210776114, 30.1043270725803, 30.1016326866963, 30.0986949871154, 30.095463219881, 30.091866695563, 30.087823561571, 30.0832240264785, 30.0779411584852, 30.0718042824719, 30.064598064254, 30.0560271138372, 30.0456642379577, 30.0328664792409, 30.0166381634173, 29.995383512023, 29.9666311419869, 29.9269062544625, 29.8724446142301, 20, 20.0992866487574, 20.1987778658839, 20.2983155533319, 20.3978803414887, 20.4974615256815, 20.5970538814448, 20.6966543922422, 20.796260963899, 29.8010645620936, 20.8958720196992, 20.9954865830927, 21.0951039613303, 21.1947236485541, 21.2943452750121, 21.3939685837807, 21.493593496968, 21.5932201164118, 21.6928485704969, 21.7924790313127, 21.8921116969745, 21.9917467869875, 22.0913845424964, 22.1910252330904, 22.2906691240923, 22.3903164843267, 22.4899675841224, 22.5896226941457, 22.6892820856006, 22.7889460266206, 22.888614783746, 22.988288620861, 23.0879678014928, 23.1876525873797, 23.287343240002, 23.3870400197103, 29.7142868959217, 23.486743187404, 23.5864530033367, 23.6861697290352, 23.7858936263979, 23.885624958565, 23.9853639878029, 24.0851109788725, 24.1848661985415, 24.2846299172733, 24.3844024085183, 24.4841839497909, 24.5839748236319, 24.6837753181654, 24.7835857287758, 24.8834063591202, 24.9832375223667, 25.0830795430067, 25.1829327578276, 29.6171448515155, 25.2827975190689, 25.3826741941813, 25.4825631716602, 25.5824648589361, 25.6823796912861, 25.7823081276471, 25.8822506637417, 25.9822078278468, 26.0821801933113, 26.1821683788585, 26.2821730607998, 26.3821949758609, 26.482234934283, 26.5822938276285, 29.5148759694037, 26.6823726493158, 26.7824724970099, 26.8825946040959, 26.9827403478161, 27.0829112850487, 27.1831091758242, 27.283336026885, 27.3835941282532, 27.4838861281617, 29.4108704451581, 27.5842150845333, 27.6845846449453, 27.7849990464475, 27.8854632367103, 27.9859831360428, 28.0865659498792, 29.3067361736195, 28.1872205245328, 28.2879579643369, 28.3887923780716, 29.2030641097122, 28.4897421297855, 28.5908314496745, 28.6920929845482, 29.0999759013086, 28.7935707828626, 28.997430828688, 28.8953250739844 )) y1 = np.full_like(x1, 1) y2 = np.full_like(x2, 2) y3 = np.full_like(x3, 3) data = ( np.array((x1, y1, z1)), np.array((x2, y2, z2)), np.array((x3, y3, z3)), ) # plot first 2 data sets sorted_data = nearest_neighbor_sort(data[:2]) mirrored_data = mirror_data(sorted_data) plot_data(mirrored_data) # plot last 2 data sets (here interpolation is wrong) sorted_data = nearest_neighbor_sort(data[1:]) mirrored_data = mirror_data(sorted_data) plot_data(mirrored_data) plt.show() if __name__ == '__main__': demo()  