I created 3d bar graph with matplotlib with the following code:
fig = plt.figure()
cmap = get_cmap(len(os.listdir(conv1d_kernel_path)))
ax = fig.add_subplot(111, projection='3d')
for f in os.listdir(conv1d_kernel_path):
step = int(re.findall(r'\d+', f)[0])
conv1d_kernel_histo[f]['bins'] = convert_bins(30, min_weight, max_weight, conv1d_kernel_histo[f])
bin_counts = conv1d_kernel_histo[f]['bins'][:, 2]
width = (max_weight-min_weight)/30 #ToDo change 30 to numbins
xs = conv1d_kernel_histo[f]['bins'][:, 0] + width / 2
ax.bar(xs, list(bin_counts), width=width, zs=step, zdir='y', color=cmap(step), ec=cmap(step+20), alpha=0.8)
ax.set_xlabel('weights')
ax.set_ylabel('step')
ax.set_zlabel('count')
plt.show()
The directory and convert bins function isn't so important, just that it gives me the info I can use to define the input data that I iteratively pass to the ax.bar function. Anyways, I receive the following output:
I want to invert the axis titled 'steps', and this question seems to be nearly what I need; however, when I used ax.invert_yaxis() the axis titled 'weights' is inverted. When I alternatively use ax.invert_xaxis() the same axis is inverted. Out of curiosity, I tried ax.invert_zaxis() but that worked as one would think, and flipped the whole graph upside down. Does anybody have a solution to this problem? A different method for inverting the axis? Thanks, all help is appreciated
Well inverting the axis limits like ax.set_ylim(150,0) should work fine. Sample plot:
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter
import numpy as np
fig = plt.figure()
ax = fig.gca(projection='3d')
# Make data.
X = np.arange(-5, 5, 0.25)
Y = np.arange(-5, 5, 0.25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = np.sin(R)
# Plot the surface.
surf = ax.plot_surface(X, Y, Z, cmap=cm.coolwarm,
linewidth=0, antialiased=False)
# Invert Y-Axis
ax.set_ylim(4,-4)
# Customize the z axis.
ax.set_zlim(-1.01, 1.01)
ax.zaxis.set_major_locator(LinearLocator(10))
ax.zaxis.set_major_formatter(FormatStrFormatter('%.02f'))
# Add a color bar which maps values to colors.
fig.colorbar(surf, shrink=0.5, aspect=5)
plt.show()
Original:
Inverted Y-Axis:
Related
Trying to visualize hyperparamt and the result of them, I CAN NOT get to plot them in a 3d plot
I try to build a function as:
PlotGridSearch(grid,xparam,yparam,zlabels):
to be called as
gs= GridSearchCV(DecisionTreeClassifier()
,HyperParams
, scoring='accuracy'
, cv=50).fit(train_data,train_labels)
PlotGridSearch(gs
,'param_max_depth'
,'param_max_leaf_nodes'
,'mean_test_score')
But I can get to convert the mean_test_score columns to the necesary matrix (2 dimensional arrray) with the correct labels stracted from param_max_depth y param_max_leaf_nodes
any tips ?
There's a nice official documentation about 3D surface matplotlib plot.
# This import registers the 3D projection, but is otherwise unused.
from mpl_toolkits.mplot3d import Axes3D # noqa: F401 unused import
import matplotlib.pyplot as plt
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter
import numpy as np
fig = plt.figure()
ax = fig.gca(projection='3d')
# Make data.
X = np.arange(-5, 5, 0.25)
Y = np.arange(-5, 5, 0.25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = np.sin(R)
# Plot the surface.
surf = ax.plot_surface(X, Y, Z, cmap=cm.coolwarm,
linewidth=0, antialiased=False)
# Customize the z axis.
ax.set_zlim(-1.01, 1.01)
ax.zaxis.set_major_locator(LinearLocator(10))
ax.zaxis.set_major_formatter(FormatStrFormatter('%.02f'))
# Add a color bar which maps values to colors.
fig.colorbar(surf, shrink=0.5, aspect=5)
plt.show()
If you are running python in Jupyter Notebook, you can use %matplotlib notebook to make it interactive.
And in your case, if you want to get the proper X,Y and Z, you could get the values from gs.cv_results_, which is:
m = len(param_grid['max_depth'])
n = len(param_grid['max_leaf_nodes'])
X = np.reshape(gs.cv_results_['param_max_depth'].data,[n,m]) # do mind the order of reshape, it might diff
Y = np.reshape(gs.cv_results_['param_max_leaf_nodes'].data,[n,m])
Z = np.reshape(gs.cv_results_['mean_test_score'],[n,m])
I'm fairly new to scatter plots and python in general. I am trying to plot a third variable against an x and a y, however, I'm not quite sure how to about specifying that argument? So I would have X values which are ints, y values which are also ints and then on the graph itself I want the model scores to show. Is there any way to do this sort of thing?
Thank you.
You can use color to plot a third value. Here is a very minimal example :
import matplotlib.pyplot as plt
import matplotlib.cm as cm
import numpy as np
x = np.random.rand(100)
y = np.random.rand(100)
z = np.random.rand(100)
plt.scatter(x,y, c=z, s=5, cmap=cm.hsv)
cbar= plt.colorbar()
plt.show()
Edit
You could also use the size of markers, their transparency, hue or rgb values to depict even more information. Here is an example with marker size, alpha level and color on a perceptually uniform colormap.
import matplotlib.pyplot as plt
import numpy as np
import matplotlib.colors as colors
import matplotlib.cm as cmx
x = np.random.rand(100)
y = np.random.rand(100)
z = np.random.rand(100)
t = np.random.rand(100)
w = np.random.rand(100)
fig, ax = plt.subplots(1, 1)
cmap = plt.get_cmap('plasma')
cNorm = colors.Normalize(vmin=0, vmax=max(z))
scalarMap = cmx.ScalarMappable(norm=cNorm, cmap=cmap)
for i in range(100):
ax.scatter(x[i],y[i], c=scalarMap.to_rgba(z[i]), s=t[i]*100, cmap=cmx.plasma, alpha=w[i], edgecolor='none')
scalarMap.set_array([])
fig.colorbar(scalarMap,ax=ax)
for a in [0.1, 0.5, 0.9]:
ax.scatter([], [], c='k', alpha=0.5, s=a*100, label=str(a), edgecolors='none')
l1 = ax.legend(scatterpoints=1, frameon=True, loc='lower left' ,markerscale=1)
for b in [0.25, 0.5, 0.75]:
ax.scatter([], [], c='k', alpha=b, s=50, label=str(b), edgecolors='none')
ax.legend(scatterpoints=1, frameon=True, loc='lower right' ,markerscale=1)
fig.show()
At face value, that question doesn't really make sense because a conventional scatterplot has only two axes, and of course you can't plot points with three dimensions (x, y and accuracy).
However, there are alternative ways to do so.
Use colours
import numpy as np
from matplotlib import pyplot as plt
x = np.random.rand(200)
y = np.random.rand(200)
fig, ax = plt.subplots(figsize=(5, 5))
ax.scatter(x, y, c=(x + y), cmap='RdPu')
scatter takes a c argument, which can be a numeric value, as well as a cmap argument, which can be a string referencing a colormap.
The colormap object translates the numbers provided in c into points along a colour mapping, which you can think of as a gradient bar.
Use 3D axes
from mpl_toolkits.mplot3d import Axes3D
fig = plt.figure(figsize=(5, 5))
ax = Axes3D(fig)
ax.scatter(x, y, (x + y))
This turns your 3rd dimension, accuracy, into an ordinary spatial dimension.
Use size of the markers
Very similar to the color option in the first part, you can change the size of the scatter markers (given you have some idea about the scale of the values). So based on the first example, you can also do;
import numpy as np
from matplotlib import pyplot as plt
x = np.random.rand(200)
y = np.random.rand(200)
fig, ax = plt.subplots(figsize=(5, 5))
ax.scatter(x, y, c='k', s=5*(x + y), cmap='RdPu')
scatter takes also the s argument, that changes the size of the markers.
I'm using a newer version of matplotlib and the argument that sets the linewidth was removed. They seem to have changed it so I set it in Collections object, but I can't find a way of doing this.
I tried their example with a different linewidth:
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter
import numpy as np
fig = plt.figure()
ax = fig.gca(projection='3d')
# Make data.
X = np.arange(-5, 5, 0.25)
Y = np.arange(-5, 5, 0.25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = np.sin(R)
# Plot the surface.
surf = ax.plot_surface(X, Y, Z, cmap=cm.coolwarm,
linewidth=10, antialiased=False)
# Customize the z axis.
ax.set_zlim(-1.01, 1.01)
ax.zaxis.set_major_locator(LinearLocator(10))
ax.zaxis.set_major_formatter(FormatStrFormatter('%.02f'))
# Add a color bar which maps values to colors.
fig.colorbar(surf, shrink=0.5, aspect=5)
plt.show()
But as the figure shows, it doesn't add lines to my surface.
What is the new method for setting linewidths?
Thanks!
The linewidth can of course only take effect if there is actually a line to be shown. So one would need to specify the color of the lines to show in order to see them.
surf = ax.plot_surface(X, Y, Z, cmap="RdYlGn", linewidth=2, edgecolor="limegreen")
I have an issue (bug?) with 3D plotting in matplotlib that I wonder if anyone may be able to help with please?
As can be seen by the matplotlib gallery example plots (e.g. from: https://matplotlib.org/examples/mplot3d/surface3d_demo.html), when the user sets the axis limits manually, and a tick is placed at the limit, the axis bound is extended a little:
I want the axis to show the 1.01 tick label, but this should be the vertex of the cube (with no grey space / black axis line above it). Is this possible please?
As a separate, more minor request, I'd then like to draw a solid black line around the edge of the grid to make it stand out. This is less important than fixing the bounds, however.
For reference, here is the code that makes the above plot:
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter
import numpy as np
fig = plt.figure()
ax = fig.gca(projection='3d')
# Make data.
X = np.arange(-5, 5, 0.25)
Y = np.arange(-5, 5, 0.25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = np.sin(R)
# Plot the surface.
surf = ax.plot_surface(X, Y, Z, cmap=cm.coolwarm, linewidth=0, antialiased=False)
# Customize the z axis.
ax.set_zlim(-1.01, 1.01)
ax.zaxis.set_major_locator(LinearLocator(10))
ax.zaxis.set_major_formatter(FormatStrFormatter('%.02f'))
# Add a color bar which maps values to colors.
fig.colorbar(surf, shrink=0.5, aspect=5)
plt.show()
Is it possible to disable the perspective when plotting in mplot3d, i.e. to use the orthogonal projection?
This is now official included since matplot version 2.2.2 Whats new | github
So for plotting a perspective orthogonal plot you have to add proj_type = 'ortho' then you should have something like that:
fig.add_subplot(121, projection='3d', proj_type = 'ortho')
Example Picture
]2
Example is taken from the official example script and edited
'''
======================
3D surface (color map)
======================
Demonstrates plotting a 3D surface colored with the coolwarm color map.
The surface is made opaque by using antialiased=False.
Also demonstrates using the LinearLocator and custom formatting for the
z axis tick labels.
'''
from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter
import numpy as np
# Make data.
X = np.arange(-5, 5, 0.25)
Y = np.arange(-5, 5, 0.25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = np.sin(R)
# Plot the surface.
fig = plt.figure(figsize=(16,4))
ax.view_init(40, 60)
ax = fig.add_subplot(121, projection='3d')
surf = ax.plot_surface(X, Y, Z, cmap=cm.coolwarm,
linewidth=0, antialiased=False)
ax.set_zlim(-1.01, 1.01)
ax.zaxis.set_major_locator(LinearLocator(10))
ax.zaxis.set_major_formatter(FormatStrFormatter('%.02f'))
ax = fig.add_subplot(122, projection='3d', proj_type = 'ortho')
# Plot the surface.
surf = ax.plot_surface(X, Y, Z, cmap=cm.viridis, linewidth=0, antialiased=False)
ax.set_zlim(-1.01, 1.01)
ax.zaxis.set_major_locator(LinearLocator(10))
ax.zaxis.set_major_formatter(FormatStrFormatter('%.02f'))
plt.show()
NOTE: This has been updated see this answer instead.
Sort of, you can run this snippet of code before you plot:
import numpy
from mpl_toolkits.mplot3d import proj3d
def orthogonal_proj(zfront, zback):
a = (zfront+zback)/(zfront-zback)
b = -2*(zfront*zback)/(zfront-zback)
return numpy.array([[1,0,0,0],
[0,1,0,0],
[0,0,a,b],
[0,0,0,zback]])
proj3d.persp_transformation = orthogonal_proj
It is currently an open issue found here.