How to create a 3D graph with filled-below curves and position the y-ticks?

Question

I am making my first 3D graph in Python on an Anaconda Jupyter Notebook. The idea is to obtain a graph with a format similar to the following:

The code I made is as follows:

import numpy as np
import matplotlib
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
from mpl_toolkits.mplot3d.art3d import Poly3DCollection

fig = plt.figure()
ax = Axes3D(fig)


def func(x, pos):  # formatter function takes tick label and tick position
    s = str(x)
    ind = s.index('.')
    return s[:ind] + ',' + s[ind+1:]   # change dot to comma
x_format = tkr.FuncFormatter(func)
ax.xaxis.set_major_formatter(x_format)
ax.yaxis.set_major_formatter(x_format)
df = pd.read_excel('EDS 7.xlsx', header=None, usecols=[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15], names=['A', 'B', 'C', 'D','E','F','G','H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P'])
plt.rcParams["figure.figsize"] = [14.5,10]
nomes = ['Triângulo de MoSe$_2$','Losango branco','Losango cinzento','Fundo']
ax.set_yticks(range(0,4))
ax.set_yticklabels(nomes)
ax.tick_params(axis='z', pad=10)
ax.tick_params(axis='y', pad=20)
# put 0s on the y-axis, and put the y axis on the z-axis
ax.plot(xs=df['A'], ys=df['B'], zs=df['C'], zdir='z', label='ys=0, zdir=z', color='blue', linewidth=3)
ax.plot(xs=df['D'], ys=df['E'], zs=df['F'], zdir='z', label='ys=0, zdir=z', color='red', linewidth=3)
ax.plot(xs=df['G'], ys=df['H'], zs=df['I'], zdir='z', label='ys=0, zdir=z', color='green', linewidth=3)
ax.plot(xs=df['J'], ys=df['K'], zs=df['L'], zdir='z', label='ys=0, zdir=z', color='orange', linewidth=3)
y=df['M'];
plt.xlim([0.0, 4.0])
#plt.ylim([0.0, 4.0])
ax.set_zlim(0,1400)
plt.rc('xtick', labelsize=16)
plt.rc('ytick', labelsize=16)
#plt.xticks(np.arange(0.0,1.4,0.1).round(decimals=1))
#plt.yticks(np.arange(-0.8,1.3,0.2).round(decimals=1))
ax.w_xaxis.set_pane_color((1.0, 1.0, 1.0, 1.0))
ax.w_yaxis.set_pane_color((1.0, 1.0, 1.0, 1.0))
ax.w_zaxis.set_pane_color((1.0, 1.0, 1.0, 1.0))
ax.xaxis._axinfo["grid"]['linestyle'] = '--'
ax.xaxis._axinfo["grid"]['color'] = 'silver'
ax.yaxis._axinfo["grid"]['linestyle'] = '--'
ax.yaxis._axinfo["grid"]['color'] = 'silver'
ax.zaxis._axinfo["grid"]['linestyle'] = '--'
ax.zaxis._axinfo["grid"]['color'] = 'silver'
ax.set_xlabel('Energia (keV)', fontsize=20, labelpad=18)
ax.set_zlabel('Contagens', fontsize=20, labelpad=18)
#plt.show()
plt.savefig('output.png', dpi=500, bbox_inches='tight')

Excel file:

The graphic I got is this:

I am having two problems that I am unable to solve:

The underside of the lines is not filled with color and I would like them to be opaque.
In the yy axis, the strings are too far to the left and for example the string "Triângulo de MoSe2" of the yy axis is to the left of the number 4.0 of the xx axis. I would like the y-axis strings to be more centered.

How can I adjust the code for the graph to have these two characteristics that I lack?

user_12046409 · Answer

Here is an example to create something similar to the desired plot. Some toy data are used to create 4 curves.

To fill the area below the curves, the approach from this tutorial is used. For the y tick labels, it seems ax.set_yticklabels(..., ha='left') together with ax.tick_params(axis='y', pad=0) get quite close to the desired result.

To make the polygons fully opaque, set the opaqueness alpha in PolyCollection(...) to a value closer to 1. Usually a small bit of transparency gives a better feeling of being a 3D plot. You can leave out the call to ax.plot(...) if the thicker "border" isn't needed.

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
from matplotlib.collections import PolyCollection

def polygon_under_graph(xlist, ylist):
    return [(xlist[0], 0.), *zip(xlist, ylist), (xlist[-1], 0.)]

x_cols = {col: np.linspace(0, 4, 50) for col in [*'ADGJ']}
z_cols = {col: 1400 ** np.random.rand(50) for col in [*'CFIL']}
df = pd.DataFrame({**x_cols, **z_cols})

fig = plt.figure()
ax = Axes3D(fig)

plt.rcParams["figure.figsize"] = [14.5, 10]
nomes = ['Triângulo de MoSe$_2$', 'Losango branco', 'Losango cinzento', 'Fundo']
ax.set_yticks(range(0, 4))
ax.set_yticklabels(nomes, ha='left')
ax.tick_params(axis='z', pad=10)
ax.tick_params(axis='y', pad=0)

color_list = ['cornflowerblue', 'crimson', 'limegreen', 'orange']
verts = []
ys = [3, 2, 1, 0]
for x_col, z_col, y, color in zip(['A', 'D', 'G', 'J'], ['C', 'F', 'I', 'L'], ys, color_list):
    xs = df[x_col].to_numpy()
    zs = df[z_col].to_numpy()
    ax.plot(xs=xs, ys=np.repeat(y, len(xs)), zs=zs, zdir='z', color=color, linewidth=3)
    verts.append(polygon_under_graph(xs, zs))
poly = PolyCollection(verts, facecolors=color_list, alpha=.8)
ax.add_collection3d(poly, zs=ys, zdir='y')

plt.show()

About having the outlines of the 3 panes in black, some experimenting with 3D figures from Matplotlib visibility of pane edge leads to the following. It is unclear to me why that hack works (an other approaches don't).

def lims(mplotlims):
    scale = 1.021
    offset = (mplotlims[1] - mplotlims[0]) * scale
    return mplotlims[1] - offset, mplotlims[0] + offset

xlims, ylims, zlims = lims(ax.get_xlim()), lims(ax.get_ylim()), lims(ax.get_zlim())
i = np.array([xlims[0], ylims[0], zlims[0]])
f = np.array([xlims[0], ylims[0], zlims[1]])
p = art3d.Poly3DCollection(np.array([[i, f]]))
p.set_color('black')
ax.add_collection3d(p)

ax.xaxis.pane.set_edgecolor('#000000FF')
ax.yaxis.pane.set_edgecolor('#000000FF')
ax.zaxis.pane.set_edgecolor('#000000FF')

How to create a 3D graph with filled-below curves and position the y-ticks?

1 Answers