我正在绘制一个点云,并通过残差误差进行着色。我希望色图保持在0的中心,以便0误差为白色。
我看到 matplotlib的答案。那么Mayavi呢?
from mayavi import mlab
mlab.points3d(x, y, z, e, colormap='RdBu')
from mayavi import mlab
mlab.points3d(x, y, z, e, colormap='RdBu')
如果有人想要这样做,但希望使用整个色条的范围,那么我做了一个解决方案(在这里得到帮助),可以将mayavi的色条拉伸,使其中心位于零:
#Mayavi surface
s = mlab.surf(data)
#Get the lut table of the data
lut = s.module_manager.scalar_lut_manager.lut.table.asarray()
maxd = np.max(data)
mind = np.min(data)
#Data range
dran = maxd - mind
#Proportion of the data range at which the centred value lies
zdp = abs(mind / dran)
#The +0.5's here are because floats are rounded down when converted to ints
#index equal portion of distance along colormap
cmzi = int(zdp * 255 + 0.5)
#linspace from zero to 128, with number of points matching portion to side of zero
topi = np.linspace(0, 127, cmzi) + 0.5
#and for other side
boti = np.linspace(128, 255, 255 - cmzi) + 0.5
#convert these linspaces to ints and map the new lut from these
shift_index = np.hstack([topi.astype(int), boti.astype(int)])
s.module_manager.scalar_lut_manager.lut.table = self.lut[shift_index]
#Force update of the figure now that we have changed the LUT
mlab.draw()
mlab.points3d
显式设置颜色映射的vmin
和vmax
。所以,您只需要确保vmin
= -vmax
即可。类似于这样:mylimit = 10
mlab.points3d(x, y, z, e, colormap='RdBu',vmin=-mylimit,vmax=mylimit)
或者,您可以使用类似以下的方式自动设置限制:
mylimit = max(abs(e.min()),abs(e.max()))