Overlapping/crowded labels on y-axis python [duplicate] - python-3.x

This question already has answers here:
How to change spacing between ticks
(4 answers)
Closed 5 months ago.
I'am kind of in a rush to finish this for tomorrows presentation towards the project owner. We are a small group of economic students in germany trying to figure out machine learning with python. We set up a Random Forest Classifier and are desperate to show the estimators important features in a neat plot. By applying google search we came up with the following solution that kind of does the trick, but leaves us unsatisfied due to the overlapping of the labels on the y-axis. The code we used looks like this:
feature_importances = clf.best_estimator_.feature_importances_
feature_importances = 100 * (feature_importances / feature_importances.max())
sorted_idx = np.argsort(feature_importances)
pos = np.arange(sorted_idx.shape[0])
plt.barh(pos, feature_importances[sorted_idx], align='center', height=0.8)
plt.yticks(pos, df_year_four.columns[sorted_idx])
plt.show()
Due to privacy let me say this: The feature names on the y-axis are overlapping (there are about 30 of them). I was looking into the documentation of matplotlib in order to get an understanding of how to do this by myself, unfortunately I couldn't find anything helpful. Seems like training and testing models is easier than understanding matplotlib and creating plots :D
Thank you so much for helping out and taking the time, I appreciate it.

I see your solution, and I want to just add this link here to explain why: How to change spacing between ticks in matplotlib?
The spacing between ticklabels is exclusively determined by the space between ticks on the axes. Therefore the only way to obtain more space between given ticklabels is to make the axes larger.
The question I linked shows that by making the graph large enough, your axis labels would naturally be spaced better.

You are using np.argsort that will return a numpy array with many indices. And you are using that array as labels for your Y-Axis thus there is overlapping of labels.
My suggestion will be to use an index for sorted_idx like,
plt.yticks(pos, df_year_four.columns[sorted_idx[0]])
This will plot only for 1 label.

Got it guys!
'Geistesblitz' as we say in germany! (spiritual lightening)
See the variable feature_importances in the third top row? Add feature_importnaces[:-15]
to view only the top half of the features and loosen up the y-axis. Yes!!! This does well because there are way less important features.

Related

Is there a way to dull/fade the coloring of marks in Altair?

I have the following DataFrame (only a part of it is shown):
I use it to generate the following plot in Altair. I generated this plot based on a modification of the code suggested in this post.
However, due to the fact that each of my Y labels has a different number of associated data points, the only way I could make the plot appear as desired was by using np.resize to repeat values. This works almost perfectly, but leads to the unfortunate issue that some of the marks in the plot appear darker than others, which can be misleading because it does not actually relate to the data in any way. Is there any way to get around this in Altair?
It sounds like you're asking about the opacity of the marks, which defaults to semi-transparent. You can adjust this with the opacity argument to mark_point(); for example:
alt.Chart(data).mark_point(opacity=1)

STL decomposition getting rid of NaN values

Following links were investigated but didn't provide me with the answer I was looking for/fixing my problem: First, Second.
Due to confidentiality issues I cannot post the actual decomposition I can show my current code and give the lengths of the data set if this isn't enough I will remove the question.
import numpy as np
from statsmodels.tsa import seasonal
def stl_decomposition(data):
data = np.array(data)
data = [item for sublist in data for item in sublist]
decomposed = seasonal.seasonal_decompose(x=data, freq=12)
seas = decomposed.seasonal
trend = decomposed.trend
res = decomposed.resid
In a plot it shows it decomposes correctly according to an additive model. However the trend and residual lists have NaN values for the first and last 6 months. The current data set is of size 10*12. Ideally this should work for something as small as only 2 years.
Is this still too small as said in the first link? I.e. I need to extrapolate the extra points myself?
EDIT: Seems that always half of the frequency is NaN on both ends of trend and residual. Same still holds for decreasing size of data set.
According to this Github link another user had a similar question. They 'fixed' this issue. To avoid NaNs an extra parameter can be passed.
decomposed = seasonal.seasonal_decompose(x=data, freq=12, extrapolate_trend='freq')
It will then use a Linear Least Squares to best approximate the values. (Source)
Obviously the information was literally on their documentation and clearly explained but I completely missed/misinterpreted it. Hence I am answering my own question for someone who has the same issue, to save them the adventure I had.
According to the parameter definition below, setting extrapolate_trend other than 0 makes the trend estimation revert to a different estimation method. I faced this issue when I had a few observations for estimation.
extrapolate_trend : int or 'freq', optional
If set to > 0, the trend resulting from the convolution is
linear least-squares extrapolated on both ends (or the single one
if two_sided is False) considering this many (+1) closest points.
If set to 'freq', use `freq` closest points. Setting this parameter
results in no NaN values in trend or resid components.

Gnuplot: how to mimic sketch graphs

I want to plot a figure like this one:
but with only sketched data curves. The x and y axes should not be sketched.
Is this possible using Gnuplot?
I think you may find this link useful, since it's exactly what you are asking for :)
http://rfonseca.github.io/xkcd-gnuplot/
Essentially, it applies a function to jiggle the line and make it pseudo-hand-drawn:
jiggle(x) = x*(1+(2*rand(0)-0.5)*0.015)
plot jiggle(sin(x))
And this is the result:
You may also want to increase samples with set samples 1000 to have better results avoiding spikes in jiggled lines.
(As a curiosity, that page is inspired by a StackExchange answer, that contains a very advanced (and amazing, IMHO) approach to this problem, unfortunately only for Mathematica users.)

D3 - Difference between basis and linear interpolation in SVG line

I implemented a multi-series line chart like the one given here by M. Bostock and ran into a curious issue which I cannot explain myself. When I choose linear interpolation and set my scales and axis everything is correct and values are well-aligned.
But when I change my interpolation to basis, without any modification of my axis and scales, values between the lines and the axis are incorrect.
What is happening here? With the monotone setting I can achieve pretty much the same effect as the basis interpolation but without the syncing problem between lines and axis. Still I would like to understand what is happening.
The basis interpolation is implementing a beta spline, which people like to use as an interpolation function precisely because it smooths out extreme peaks. This is useful when you are modeling something you expect to vary smoothly but only have sharp, infrequently sampled data. A consequence of this is that resulting line will not connect all data points, changing the appearance of extreme values.
In your case, the sharp peaks are the interesting features, the exception to the typically 0 baseline value. When you use a spline interpolation, you are smoothing over these peaks.
Here is a fun demo to play with the different types of line interpoations:
http://bl.ocks.org/mbostock/4342190
You can drag the data around so they resemble a sharp peak like yours, even click to add new points. Then, switch to a basis interpolation and watch the peak get averaged out.

Radial stack issue

I'm trying to draw a radial chart (radar chart) using the Stack layout and Nest (as advised by mbostock). Code is here: http://bl.ocks.org/3017677 Purpose is to draw stacked areas along three axes of metrics (axis 1, 2 and 3). Areas map to min, average and max values along those metrics. Max area encompasses the average area which encompasses the min one.
The computations seem really fine until the path data string is built. That is, when entering for the layers, d.values looks OK while area(d.values) returns a somewhat correct motions sequence but microscopic values (e-14).
Didn't understand what I'm doing wrong yet :)
Issue was with the angle scale's domain. WIP at http://bl.ocks.org/3017677 for the curious minds.

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