Plotly等高线图如何实现坐标轴刻度等间距分布而非按数值缩放

你可以将数值坐标轴改为类别坐标轴，使用数组索引作为坐标值，再替换刻度文本为原始数值即可实现所有刻度等间距，修改后的完整代码如下：

import numpy as np
import plotly.graph_objects as go

Q_0 = [0.01, 0.02, 0.05, 0.08, 0.15, 0.4, 1., 5., 10., 20., 50.] 
w_0 = [0., 1., 2., 3., 4., 5., 8.,15]

def f(q,w):
  return np.sqrt(q*w)

x_idx = np.zeros([len(Q_0), len(w_0)])
y_idx = np.zeros([len(Q_0), len(w_0)])
z = np.zeros([len(Q_0), len(w_0)])
# 存储原始数值用于悬浮显示
x_original = np.zeros_like(x_idx)
y_original = np.zeros_like(y_idx)

for i, q in enumerate(Q_0):
  for j,w in enumerate(w_0):
      z[i,j] = f(q,w)
      x_idx[i,j] = i # 用索引作为坐标值，保证间距相等
      y_idx[i,j] = j
      x_original[i,j] = q
      y_original[i,j] = w

fig = go.Figure(go.Contour(
        x = x_idx.reshape(-1),
        y = y_idx.reshape(-1),
        z = z.reshape(-1),
        # 配置悬浮显示原始数值
        customdata = np.stack((x_original.reshape(-1), y_original.reshape(-1)), axis=-1),
        hovertemplate = 'Q_0: %{customdata[0]}<br>w_0: %{customdata[1]}<br>z值: %{z:.2f}<extra></extra>',
        colorscale = 'Blues',
        contours = dict(
            showlabels = True,
            labelfont = dict(
                family = 'Raleway',
                color = 'white'
            )
        ),
        hoverlabel = dict(
            bgcolor = 'white',
            bordercolor = 'black',
            font = dict(
                family = 'Raleway',
                color = 'black'
            )
        )
))
fig.update_layout(
    xaxis_title="$Q_0$",
    yaxis_title="$w_0$",
    xaxis = dict(
        tickmode = 'array',
        tickvals = list(range(len(Q_0))), # 刻度位置对应索引
        ticktext = [str(i) for i in Q_0] # 刻度文本显示原始数值
    ),
    yaxis = dict(
        tickmode = 'array',
        tickvals = list(range(len(w_0))),
        ticktext = [str(i) for i in w_0]
    )
)
fig.show()

核心修改点 #

• 生成坐标时用Q_0和w_0的索引作为x、y的坐标值，从根源上保证每个刻度的间距完全相等
• 坐标轴配置中，tickvals对应索引值，ticktext保留原始数值标签，显示效果和需求完全一致
• 新增customdata和hovertemplate配置，保证鼠标悬浮时显示原始的Q_0、w_0数值，不会出现显示索引的问题

内容的提问来源于stack exchange，提问作者jon