How to set interact arguments programmatically? - python

Suppose I have function, that accepts list of arguments. List can be of variable length and function is ok with it. For example:
import math
import numpy as np
import matplotlib.pyplot as plt
from ipywidgets import interact, interactive, fixed, interact_manual
import ipywidgets as widgets
%matplotlib inline
def PlotSuperposition(weights):
def f(x):
y = 0
for i, weight in enumerate(weights):
if i==0:
y+=weight
else:
y += weight*math.sin(x*i)
return y
vf = np.vectorize(f)
xx = np.arange(0,6,0.1)
plt.plot(xx, vf(xx))
plt.gca().set_ylim(-5,5)
PlotSuperposition([1,1,2])
shows
I can hardcode interact for given number of arguments, like here
interact(lambda w0, w1, w2: PlotSuperposition([w0,w1,w2]), w0=(-3,+3,0.1), w1=(-3,+3,0.1), w2=(-3,+3,0.1))
which shows
But how can I make number of sliders defined programmatically?
I tried
n_weights=10
weight_sliders = [widgets.FloatSlider(
value=0,
min=-10.0,
max=10.0,
step=0.1,
description='w%d' % i,
disabled=False,
continuous_update=False,
orientation='horizontal',
readout=True,
readout_format='.1f',
) for i in range(n_weights)]
interact(PlotSuperposition, weights=weight_sliders)
but got error
TypeError: 'FloatSlider' object is not iterable
inside PlotSuperposition saying that interact doesn't pass a list of values to the function.
How to accomplish?

First, modify your function to take an arbitrary number of keyword arguments instead of a plain list:
def PlotSuperposition(**kwargs):
def f(x):
y = 0
for i, weight in enumerate(kwargs.values()):
if i==0:
y+=weight
else:
y += weight*math.sin(x*i)
return y
vf = np.vectorize(f)
xx = np.arange(0,6,0.1)
plt.plot(xx, vf(xx))
plt.gca().set_ylim(-5,5)
Notice the asterisks in front of kwargs. Then, call interact with a dictionary of key/value arguments:
kwargs = {'w{}'.format(i):slider for i, slider in enumerate(weight_sliders)}
interact(PlotSuperposition, **kwargs)

Related

`update` function doesn't work correctly for bokeh interactors in python

I have a source code that plots the alphashape of a stock price. There's a slider to update the plot dynamically. But the update function doesn't work as expected.
Here's the source code.
x=[76.84,76.85,76.86,76.87,76.88,76.9,76.91,76.92,76.93,76.94,76.97,76.97,76.98,76.99,77.0,77.03,77.03,77.04,77.05,77.06,77.09,77.09,77.1,77.11,77.12,77.15,77.16,77.16,77.17,77.18,77.21,77.22,77.22,77.23,77.24,77.27,77.28,77.28,77.29,77.3,77.33,77.34,77.35,77.35,77.36,77.39,77.4,77.41,77.41,77.42,77.45,77.46,77.47,77.47,77.48,77.51,77.52,77.53,77.54,77.54,77.57,77.58,77.59,77.6,77.6,77.63,77.64,77.65,77.66,77.66,77.69,77.7,77.71,77.72,77.73,77.75,77.76,77.77,77.78,77.79,77.81,77.82,77.83,77.84,77.85,77.87,77.88,77.89,77.9,77.91,77.93,77.94,77.95,77.96,77.97,77.99,78.0,78.01,78.02,78.03,78.05,78.06,78.07,78.08,78.09,78.13,78.14,78.15,78.17,78.18,78.19,78.2,78.21,78.24,78.24,78.25,78.26,78.27,78.3,78.3,78.31,78.32,78.33,78.36,78.36,78.37,78.38,78.39,78.42,78.43,78.43,78.44,78.45,78.48,78.49,78.49,78.5,78.51,78.54,78.55,78.55,78.56,78.57,78.6,78.61,78.62,78.62,78.63,78.66,78.67,78.68,78.68,78.69,78.72,78.73,78.74,78.74,78.75,78.78,78.79,78.8,78.81,78.81,78.84,78.85,78.86,78.87,78.87,78.91,78.92,78.93,78.94,78.96,78.97,78.98,78.99,79.0,79.02,79.03,79.04,79.05,79.06,79.08,79.09,79.1,79.11,79.12,79.2,79.21,79.22,79.23,79.24,79.26,79.27,79.28,79.29,79.3,79.32,79.33,79.34,79.35,79.36,79.38,79.39,79.4,79.41,79.42,79.44,79.45,79.46,79.47,79.48,79.51,79.51,79.52,79.53,79.54,79.57,79.57,79.58,79.59,79.6,79.63,79.63,79.64,79.65,79.66,79.69,79.7,79.7,79.71,79.72,79.75,79.76,79.76,79.77,79.78,79.81,79.82,79.82,79.83,79.84,79.87,79.88,79.89,79.89,79.9,79.94,79.95,79.95,79.96,79.99,80.0,80.01,80.02,80.02,80.05,80.06,80.07,80.08,80.08,80.11,80.12,80.13,80.14,80.14,80.17,80.18,80.19,80.2,80.21,80.23,80.24,80.25,80.26,80.27,80.29,80.3,80.31,80.32,80.33,80.35,80.36,80.37,80.38,80.39,80.41,80.42,80.43,80.44,80.45,80.47,80.48,80.49,80.5,80.51,80.53,80.54,80.55,80.56,80.57,80.59,80.6,80.61,80.62,80.63,80.65,80.66,80.67,80.68,80.69,80.71,80.72,80.73,80.74,80.75,80.78,80.78,80.79,80.8,80.81,80.84,80.84,80.85,80.86,80.87,80.9,80.9,80.91,80.92,80.93,80.96,80.97,80.97,80.98,80.99,81.02,81.03,81.03,81.04,81.05,81.08,81.09,81.1,81.1,81.11,81.14,81.15,81.16,81.16,81.17,81.2,81.21,81.22,81.22,81.23,81.28,81.29,81.29,81.32,81.33,81.34,81.35,81.35,81.38,81.39,81.4,81.41,81.41,81.44,81.45,81.46,81.47,81.48,81.5,81.51,81.52,81.53,81.54,81.56,81.57,81.58,81.59,81.6,81.62,81.63,81.64,81.65,81.66,81.68,81.69,81.7,81.71,81.72,81.74,81.75,81.76,81.77,81.78,81.8,81.81,81.82,81.83,81.84,81.86,81.87,81.88,81.89,81.9,81.92,81.93,81.94,81.95,81.96,81.98,81.99,82.0,82.01,82.02,82.05,82.06,82.07,82.08,82.11,82.11,82.12,82.13,82.14,82.17,82.18,82.18,82.19,82.2,82.23,82.24,82.24,82.25,82.26,82.29,82.3,82.3,82.31,82.32,82.35,82.36,82.37,82.37,82.38,82.41,82.42,82.43,82.43,82.44,82.59,82.6,82.61,82.62,82.62,82.65,82.66,82.67,82.68,82.68,82.71,82.72,82.73,82.74,82.75,82.77,82.78,82.79,82.8,82.81,82.83,82.84,82.85,82.86,82.87,82.89,82.9,82.91,82.92,82.93,82.95,82.96,82.97,82.98,82.99,83.01,83.02,83.03,83.04,83.05,83.07,83.08,83.1,83.11,83.13,83.14,83.15,83.16,83.17,83.19,83.2,83.21,83.22,83.23,83.26,83.26,83.27,83.28,83.29,83.32,83.32,83.33,83.34,83.35,83.38,83.38,83.39,83.4,83.41,83.44,83.45,83.45,83.46,83.47,83.5,83.51,83.51,83.52,83.53,83.56,83.57,83.57,83.58,83.59,83.62,83.63,83.64,83.64,83.65,83.68,83.69,83.7,83.7,83.71,83.74,83.75,83.76,83.76,83.77,83.8,83.81,83.82,83.83,83.83,83.86,83.87,83.88,83.89,83.89,83.92,83.93,83.94,83.95,83.95,83.98,83.99,84.0,84.01,84.02,84.04,84.05,84.06,84.07,84.08,84.1,84.11,84.12,84.13,84.14,84.16,84.17,84.18,84.19,84.2,84.22,84.23,84.24,84.25,84.26,84.28,84.29,84.3,84.31,84.32,84.34,84.35,84.36,84.37,84.38,84.43,84.44,84.46,84.47,84.48,84.49,84.5,84.53,84.53,84.54,84.55,84.56,84.59,84.59,84.6,84.61,84.62,84.65,84.65,84.66,84.67,84.68,84.71,84.72,84.72,84.73,84.74,84.77,84.78,84.78,84.79,84.8,84.83,84.84,84.84,84.85,84.86,84.89,84.9,84.91,84.91,84.92,84.95,84.96,84.97,84.97,84.98,85.01,85.02,85.03,85.03,85.04,85.07,85.08,85.09,85.1,85.1,85.13,85.14,85.15,85.16,85.16,85.19,85.2,85.22,85.22,85.25,85.26,85.27,85.28,85.29,85.31,85.32,85.33,85.34,85.35,85.37,85.38,85.39,85.4,85.41,85.43,85.44,85.45,85.46,85.47,85.61,85.62,85.63,85.64,85.65,85.67,85.68,85.69,85.7,85.71,85.73,85.74,85.75,85.76,85.77,85.8,85.8,85.81,85.82,85.83,85.86,85.86,85.87,85.88,85.89,85.92,85.92,85.93,85.94,85.95,85.98,85.99,85.99,86.0,86.01,86.04,86.05,86.05,86.06,86.07,86.1,86.11,86.11,86.12,86.13,86.16,86.17,86.18,86.18,86.19,86.22,86.23,86.24,86.28,86.29,86.3,86.3,86.31,86.34,86.35,86.36,86.37,86.37,86.4,86.41,86.42,86.43,86.43,86.46,86.47,86.48,86.49,86.5,86.52,86.53,86.54,86.55,86.56,86.58,86.59,86.6,86.61,86.62,86.64,86.65,86.66,86.67,86.68,86.7,86.71,86.72,86.73,86.74,86.78,86.79,86.8,86.82,86.83,86.84,86.85,86.86,86.88,86.89,86.9,86.91,86.92,86.94,86.95,86.96,86.97,86.98,87.0,87.01,87.02,87.03,87.04,87.07,87.07,87.08,87.09,87.1,87.13,87.13,87.14,87.15,87.16,87.19,87.19,87.2,87.21,87.22,87.25,87.26,87.26,87.27,87.28,87.31,87.32,87.32,87.33,87.34,87.37,87.38,87.38,87.39,87.4,87.43,87.44,87.45,87.45,87.46,87.49,87.5,87.51,87.51,87.52,87.55,87.56,87.61,8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y=[2.29,2.41,2.4,2.38,2.43,2.42,2.38,2.36,2.4,2.37,2.36,2.37,2.34,2.32,2.31,2.25,2.25,2.21,2.2,2.21,2.21,2.21,2.21,2.19,2.17,2.1,2.08,2.08,2.12,2.15,2.1,2.09,2.1,2.08,2.08,2.01,2.0,1.98,1.98,1.95,1.92,1.92,1.92,1.92,1.92,1.88,1.88,1.91,1.91,1.88,1.89,1.87,1.85,1.84,1.83,1.88,1.93,1.88,1.82,1.82,2.08,2.13,2.35,2.32,2.37,2.34,2.25,2.35,2.33,2.34,2.32,2.34,2.39,2.53,2.49,2.53,2.54,2.55,2.53,2.52,2.52,2.54,2.66,2.71,2.81,2.92,3.09,2.99,3.03,2.98,3.01,2.98,2.93,2.91,2.93,2.91,2.89,2.92,2.9,2.87,2.9,2.9,2.93,2.83,2.78,2.67,2.6,2.66,2.61,2.61,2.61,2.54,2.56,2.51,2.52,2.55,2.6,2.6,2.67,2.63,2.62,2.63,2.61,2.58,2.59,2.59,2.62,2.59,2.58,2.61,2.63,2.6,2.63,2.63,2.61,2.6,2.58,2.58,2.57,2.58,2.58,2.58,2.58,2.57,2.58,2.58,2.58,2.58,2.55,2.52,2.53,2.53,2.51,2.46,2.48,2.45,2.54,2.53,2.49,2.51,2.49,2.48,2.49,2.47,2.48,2.49,2.48,2.5,2.5,2.55,2.53,2.52,2.51,2.49,2.5,2.49,2.49,2.47,2.46,2.48,2.45,2.45,2.43,2.43,2.45,2.45,2.45,2.45,2.45,2.45,2.45,2.45,2.46,2.45,2.44,2.44,2.45,2.45,2.47,2.56,2.52,2.48,2.47,2.5,2.54,2.54,2.58,2.61,2.63,2.63,2.63,2.61,2.59,2.59,2.56,2.57,2.58,2.56,2.57,2.61,2.59,2.6,2.6,2.58,2.6,2.59,2.6,2.61,2.61,2.59,2.6,2.62,2.62,2.6,2.61,2.59,2.59,2.59,2.59,2.61,2.67,2.65,2.63,2.63,2.6,2.56,2.59,2.59,2.59,2.58,2.58,2.57,2.58,2.55,2.55,2.58,2.58,2.57,2.58,2.83,2.88,2.93,2.79,2.82,2.81,2.86,2.86,2.85,2.82,2.82,2.82,2.78,2.78,2.82,2.79,2.8,2.79,2.79,2.78,2.72,2.73,2.71,2.72,2.73,2.73,2.74,2.74,2.72,2.73,2.73,2.71,2.68,2.71,2.75,2.84,2.91,2.89,2.92,2.97,2.96,2.94,2.99,3.04,2.97,2.99,2.97,2.99,2.98,2.99,3.0,3.01,2.99,2.98,2.99,2.99,2.99,3.01,2.96,2.97,3.0,2.98,2.97,2.96,2.96,3.0,3.0,2.99,2.98,2.99,2.99,2.99,2.99,2.99,2.99,2.98,2.98,2.98,2.98,3.02,3.03,3.03,3.05,3.09,3.08,3.1,3.12,3.14,3.13,3.12,3.14,3.15,3.13,3.15,3.14,3.14,3.14,3.14,3.13,3.11,3.08,3.08,3.08,3.08,3.1,3.11,3.11,3.11,3.09,3.13,3.17,3.28,3.43,3.52,3.47,3.45,3.45,3.45,3.44,3.46,3.46,3.45,3.44,3.45,3.45,3.45,3.45,3.45,3.47,3.5,3.54,3.52,3.5,3.5,3.5,3.44,3.45,3.45,3.45,3.43,3.45,3.48,3.48,3.45,3.46,3.43,3.46,3.45,3.43,3.43,3.42,3.42,3.43,3.42,3.41,3.39,3.38,3.38,3.38,3.4,3.39,3.38,3.39,3.37,3.37,3.38,3.38,3.38,3.38,3.38,3.38,3.37,3.36,3.37,3.36,3.36,3.37,3.36,3.41,3.41,3.4,3.39,3.39,3.37,3.37,3.36,3.36,3.36,3.36,3.36,3.37,3.36,3.37,3.39,3.45,3.42,3.39,3.4,3.4,3.39,3.38,3.38,3.38,3.38,3.38,3.38,3.38,3.38,3.38,3.42,3.42,3.41,3.39,3.39,3.39,3.37,3.38,3.4,3.41,3.44,3.43,3.43,3.43,3.43,3.42,3.42,3.42,3.47,3.46,3.47,3.53,3.65,3.59,3.76,3.85,3.77,3.9,3.76,3.75,3.8,3.73,3.7,3.66,3.68,3.66,3.69,3.68,3.69,3.69,3.61,3.61,3.61,3.59,3.59,3.59,3.63,3.61,3.62,3.63,3.62,3.61,3.61,3.62,3.69,3.66,3.69,3.68,3.66,3.65,3.66,3.68,3.78,3.76,3.77,3.74,3.75,3.77,3.75,3.7,3.7,3.73,3.74,3.79,3.83,3.87,3.86,3.8,3.81,3.78,3.8,3.78,3.78,3.84,3.81,3.81,3.82,3.78,3.75,3.76,3.74,3.72,3.71,3.72,3.78,3.78,3.77,3.76,3.74,3.74,3.75,3.75,3.73,3.72,3.71,3.68,3.7,3.67,3.64,3.56,3.57,3.56,3.61,3.62,3.59,3.57,3.59,3.55,3.54,3.53,3.52,3.53,3.53,3.58,3.6,3.57,3.53,3.53,3.54,3.55,3.57,3.57,3.58,3.64,3.63,3.6,3.6,3.6,3.59,3.6,3.6,3.61,3.61,3.62,3.64,3.64,3.64,3.69,3.73,3.71,3.69,3.69,3.69,3.65,3.66,3.66,3.72,3.73,3.7,3.7,3.72,3.74,3.74,3.74,3.79,3.85,3.9,3.88,3.93,3.86,3.94,4.0,4.0,3.97,3.94,3.93,3.91,3.92,3.94,3.94,3.94,3.99,3.98,4.01,3.99,3.92,3.82,3.71,3.81,3.77,3.76,3.81,3.79,3.83,3.83,3.88,3.89,3.84,3.84,3.83,3.79,3.81,3.8,3.81,3.82,3.83,3.8,3.81,3.81,3.83,3.83,3.86,3.92,3.93,3.97,3.97,3.96,3.95,3.94,3.96,3.98,3.88,3.98,4.0,4.02,4.04,4.08,4.09,4.09,4.16,4.22,4.21,4.19,4.19,4.18,4.19,4.2,4.19,4.2,4.21,4.27,4.3,4.29,4.26,4.29,4.29,4.34,4.36,4.35,4.33,4.33,4.36,4.34,4.33,4.34,4.37,4.35,4.36,4.39,4.38,4.41,4.4,4.4,4.39,4.39,4.41,4.42,4.46,4.48,4.53,4.63,4.65,4.71,4.81,4.91,5.0,4.95,5.04,5.01,4.98,4.9,4.95,4.91,4.8,4.9,4.86,4.76,4.77,4.77,4.79,4.8,4.79,4.81,4.89,4.87,4.87,4.87,4.8,4.79,4.75,4.69,4.69,4.71,4.78,4.76,4.74,4.73,4.8,4.81,4.84,4.83,4.83,4.83,4.79,4.75,4.75,4.66,4.69,4.7,4.68,4.7,4.73,4.72,4.75,4.75,4.75,4.71,4.72,4.71,4.69,4.68,4.64,4.65,4.65,4.66,4.66,4.64,4.65,4.64,4.62,4.63,4.6,4.52,4.45,4.53,4.49,4.5,4.48,4.37,4.39,4.4,4.41,4.43,4.47,4.46,4.45,4.42,4.44,4.45,4.45,4.44,4.43,4.41,4.41,4.44,4.41,4.38,4.38,4.37,4.37,4.38,4.32,4.24,4.29,4.31,4.29,4.27,4.28,4.28,4.28,4.32,4.32,4.33,4.33,4.32,4.33,4.39,4.47,4.47,4.53,4.53,4.53,4.52,4.54,4.51,4.53,4.53,4.53,4.54,4.54,4.58,4.56,4.58,4.56,4.55,4.53,4.54,4.54,4.55,4.54,4.53,4.52,4.49,4.45,4.45,4.46,4.46,4.48,4.46,4.47,4.47,4.49,4.47,4.47,4.48,4.51,4.57,4.57,4.59,4.61,4.57,4.57,4.6,4.64,4.64,4.63,4.65,4.65,4.64,4.64,4.66,4.72,4.73,4.76,4.74,4.8,4.78,4.72,4.76,4.86,4.86,4.88,4.86,4.83,4.85,4.85,4.84,4.81,4.82,4.82,4.82,4.81,4.82,4.85,4.85,4.84,4.82,4.81,4.78,4.81,4.79,4.75,4.78,4.8,4.79,4.78,4.76,4.77,4.77,4.77,4.78,4.79,4.79,4.76,4.75,4.74,4.73,4.74,4.75,4.8,4.81,4.84,4.82,4.8,4.81,4.8,4.77,4.81,4.8,4.81,4.84,4.86,4.83,4.82,4.81,4.8,4.78,4.81,4.81,4.82,4.88,4.84,4.84,4.83,4.83,4.85,4.85,4.83,4.81,4.82,4.79,4.8,4.79,4.78,4.8,4.79,4.78,4.77,4.78,4.77,4.76,]
from alphashape import alphashape
from shapely.geometry import mapping
from bokeh.plotting import figure
from ipywidgets import interact
from bokeh.io import output_notebook, show, push_notebook
def alphashape_func(x, y, alpha):
length = range(len(x))
# date count
pnt = [[x[i],y[i]] for i in length]
# return a shapely.polygon/multipolygon
alpha_shape = alphashape(pnt, alpha=alpha)
# convert shapely.polygon/multipolygon to list
map = mapping(alpha_shape)['coordinates']
poly_shp = [i[0] for i in map]
bound_len = len(poly_shp)
# single alpha shape case
if bound_len == 1:
bound_x = [i[0] for i in poly_shp]
bound_y = [i[1] for i in poly_shp]
# multiple alpha shape case
else:
bound_x = [[i[0] for i in poly_shp[j]] for j in range(bound_len)]
bound_y = [[i[1] for i in poly_shp[j]] for j in range(bound_len)]
# return a dict containing 2 lists: x & y.
return {'x':bound_x, 'y':bound_y}
alpha = 5
alpha_high_pnt = alphashape_func(x,y,alpha)
plot = figure(sizing_mode='stretch_width', output_backend="webgl")
# line_pnt(plot, max_processed_xy['x'], max_processed_xy['y'],legend_label ='processed_xy',line_color='yellow', line_width=2)
alpha_shape_plt = plot.multi_line(xs=alpha_high_pnt['x'],ys=alpha_high_pnt['y'], line_color='cyan',legend_label = 'alpha_high_pnt')
# create an update function
def update(alpha=5):
alpha_high_pnt = alphashape_func(x,y,alpha)
alpha_shape_plt.data_source.data['xs'] = alpha_high_pnt['x']
alpha_shape_plt.data_source.data['ys'] = alpha_high_pnt['y']
# push new values to the notebook
push_notebook()
output_notebook()
show(plot)
interact(update, alpha=(0,25,1))
(the dynamic slider only works when you run it in jupyter in a web browser)
When I drag the slider, it shows an error message:
BokehUserWarning: ColumnDataSource's columns must be of the same length. Current lengths: ('xs', 54), ('ys', 99)
I don't see the reason of this error, since when I manually adjust the alpha value, the lengths of xs and ys equal.
Can anyone help?
===================== update ======================
Based on #bigreddot suggestion, I update the code to this, the doesn't match problem is resolved, but the plot doesn't refresh yet.
from alphashape import alphashape
from shapely.geometry import mapping
from bokeh.plotting import figure
from bokeh.io import output_notebook, show, push_notebook
from bokeh.models import ColumnDataSource
from ipywidgets import interact
output_notebook()
def alphashape_func(x, y, alpha):
length = range(len(x))
# date count
pnt = [[x[i],y[i]] for i in length]
# return a shapely.polygon/multipolygon
alpha_shape = alphashape(pnt, alpha=alpha)
# convert shapely.polygon/multipolygon to list
map = mapping(alpha_shape)['coordinates']
poly_shp = [i[0] for i in map]
bound_len = len(poly_shp)
# single alpha shape case
if bound_len == 1:
bound_x = [i[0] for i in poly_shp]
bound_y = [i[1] for i in poly_shp]
# multiple alpha shape case
else:
bound_x = [[i[0] for i in poly_shp[j]] for j in range(bound_len)]
bound_y = [[i[1] for i in poly_shp[j]] for j in range(bound_len)]
# return a dict containing 2 lists: x & y.
return {'x':bound_x, 'y':bound_y}
alpha = 5
plot = figure(sizing_mode='stretch_width', output_backend="webgl")
source = ColumnDataSource(data=alphashape_func(x,y,alpha))
alpha_shape_plt = plot.multi_line(source=source, xs='x',ys='y', line_color='cyan',legend_label = 'alpha_high_pnt')
print
# create an update function
def update(alpha=5):
source.data = alphashape_func(x,y,alpha)
# push new values to the notebook
push_notebook()
interact(update, alpha=(0,25,1))
show(plot)
In between this line:
alpha_shape_plt.data_source.data['xs'] = alpha_high_pnt['x']
and this line:
alpha_shape_plt.data_source.data['ys'] = alpha_high_pnt['y']
the CDS columns are not all the same length. If you need to update with data that has a new length you should collect all the updates up front in a new_data dict and then set
source.data = new_data
to update the CDS "all at once". This is more efficient in any case, as well, since it results in fewer property update change events being sent out.

Ipywidgets: alter slider defaults based on a scenario

I'm using ipywidges to create a plot. I'd like to have a dropdown with options (e.g. Scenario A, Scenario B). Each scenario should change the slider position (a=0, b=1), and one should be able to modify the parameters freely afterwards. Any ideas?
Here is my toy example:
import ipywidgets as widgets
def line(a=0,b=1):
#fig, ax = plt.subplots(figsize=(6, 4))
x = np.arange(-10,10)
y = a+xrange*b
plt.xlim((-10,10))
plt.ylim((-10,10))
plt.plot(x, y)
widgets.interact(line, a=(-10,10,0.1), b=(-10,10,0.1))
I was playing with an additional wrapper functions but with no success. In reality of course, I would like to have a few more scenarios and a lot more parameters.
Just as another answer, you could also link different widgets. In this case we are going to link the a and b sliders with a Dropdown menu, such that a change of the latter will call the functions on_change_* and switch the default values of the sliders (depending on the chosen scenario).
import ipywidgets as widgets
import numpy as np
import matplotlib.pyplot as plt
def line(a=0,b=0):
x = np.arange(-10,10)
y = a+x*b
plt.xlim((-10,10))
plt.ylim((-10,10))
plt.plot(x, y)
a_slider = widgets.FloatSlider(min=-10, max=10, step=0.1, value=0)
b_slider = widgets.FloatSlider(min=-10, max=10, step=0.1, value=1)
drop = widgets.Dropdown(options=["a", "b"], value="a", description='Scenario:')
def on_choose_a(d):
if drop.value == "a":
a_slider.value = 2
else:
a_slider.value = 5
return a_slider.value
def on_choose_b(d):
if drop.value == "a":
b_slider.value = 3
else:
b_slider.value = 7
return b_slider.value
widgets.dlink((drop, "value"), (a_slider, "value"), on_choose_a)
widgets.dlink((drop, "value"), (b_slider, "value"), on_choose_b)
display(drop)
widgets.interact(line, a=a_slider, b=b_slider);
All right, I think I've found a very nice workaround:
def line(a=0,b=0):
x = np.arange(-10,10)
y = a+x*b
plt.xlim((-10,10))
plt.ylim((-10,10))
plt.plot(x, y)
sliders = widgets.interact(a=(-10,10,0.1), b=(-10,10,0.1))
def test(chose_defaults):
if chose_defaults=="a":
#sliders
def h(a=5,b=5):
return(line(a,b))
if chose_defaults=="b":
#sliders
def h(a=0,b=1):
return(line(a,b))
widgets.interact(test, chose_defaults=["a","b"])
The above code basically nests two widgets. Firstly a separate widget for chosing a scenario is shown; action for the scenarios are the plots that differ only in the default setup.

Number format python

I want to have the legend of the plot shown with the value in a list. But what I get is the element index but not the value itself. I dont know how to fix it. I'm referring to the plt.plot line. Thanks for the help.
import matplotlib.pyplot as plt
import numpy as np
x = np.random.random(1000)
y = np.random.random(1000)
n = len(x)
d_ij = []
for i in range(n):
for j in range(i+1,n):
a = np.sqrt((x[i]-x[j])**2+(y[i]-y[j])**2)
d_ij.append(a)
epsilon = np.linspace(0.01,1,num=10)
sigma = np.linspace(0.01,1,num=10)
def lj_pot(epsi,sig,d):
result = []
for i in range(len(d)):
a = 4*epsi*((sig/d[i])**12-(sig/d[i])**6)
result.append(a)
return result
for i in range(len(epsilon)):
for j in range(len(sigma)):
a = epsilon[i]
b = sigma[j]
plt.cla()
plt.ylim([-1.5, 1.5])
plt.xlim([0, 2])
plt.plot(sorted(d_ij),lj_pot(epsilon[i],sigma[j],sorted(d_ij)),label = 'epsilon = %d, sigma =%d' %(a,b))
plt.legend()
plt.savefig("epsilon_%d_sigma_%d.png" % (i,j))
plt.show()
Your code is a bit unpythonic, so I tried to clean it up to the best of my knowledge. numpy.random.random and numpy.random.uniform(0, 1) are basically the same, however, the latter also allows you to pass the shape of the return array that you would like to have, in this case an array with 1000 rows and two columns (1000, 2). I then use some magic to assign the two colums of the return array to x and y in the same line, respectively.
numpy.hypot does as the name suggests and calculates the hypothenuse of x and y. It can also do that for each entry of arrays with the same size, saving you the for loops, which you should try to aviod in Python since they are pretty slow.
You used plt for all your plotting, which is fine as long as you only have one figure, but I would recommend to be as explicit as possible, according to one of Python's key notions:
explicit is better than implicit.
I recommend you read through this guide, in particular the section called 'Stateful Versus Stateless Approaches'. I changed your commands accordingly.
It is also very unpythonic to loop over items of a list using the index of the item in the list like you did (for i in range(len(list)): item = list[i]). You can just reference the item directly (for item in list:).
Lastly I changed your formatted strings to the more convenient f-strings. Have a read here.
import matplotlib.pyplot as plt
import numpy as np
def pot(epsi, sig, d):
result = 4*epsi*((sig/d)**12 - (sig/d)**6)
return result
# I am not sure why you would create the independent variable this way,
# maybe you are simulating something. In that case, the code below is
# simpler than your version and should achieve the same.
# x, y = zip(*np.random.uniform(0, 1, (1000, 2)))
# d = np.array(sorted(np.hypot(x, y)))
# If you only want to plot your pot function then creating the value range
# like this is just fine.
d = np.linspace(0.001, 1, 1000)
epsilons = sigmas = np.linspace(0.01, 1, num=10)
fig, ax = plt.subplots()
ax.set_xlim([0, 2])
ax.set_ylim([-1.5, 1.5])
line = None
for epsilon in epsilons:
for sigma in sigmas:
if line is None:
line = ax.plot(
d, pot(epsilon, sigma, d),
label=f'epsilon = {epsilon}, sigma = {sigma}'
)[0]
fig.legend()
else:
line.set_data(d, pot(epsilon, sigma, d))
# plt.savefig(f"epsilon_{epsilon}_sigma_{sigma}.png")
fig.show()

Python - How to plot argument in integral that is not the value being integrated

I want to integrate a function that has no closed form solution with an unknown variable and then plot vs the unknown variable. To try a simpler test, I tried to use the integral of f(x,c) = (x^2+c), integrated with respect to x and plot with different values of c. However, the code below gets the error
only size-1 arrays can be converted to Python scalars
even though the integral of a number, e.g. integral(5), seems to return the correct scalar value.
import numpy as np
import matplotlib.pyplot as plt
from scipy import integrate
def f(x,c):
return x**2+c
def integral(c):
return integrate.quad(f,0,10, args = (c,))[0]
y = np.linspace(0,20,200)
plt.plot(y, integral(y))
You pass a numpy array as the argument c while you wanted to integrate over x for all the items of c. Therefore you can use this:
def f(x,c):
return x**2+c
def integrate_f(c):
result = np.zeros(len(c))
counter = 0
for item in c:
result[counter] = integrate.quad(f,0,10, args = (item))[0]
counter +=1
return result
c_array = np.linspace(0,1,200)
plt.plot(c_array, integrate_f(c_array))
onno was a bit faster. But here is my similar solution. You need to loop over all the different c:
import numpy as np
import matplotlib.pyplot as plt
from scipy import integrate
def f(x,c):
return x**2+c
def getIntegral(c_list):
result = []
for c in c_list:
integral = integrate.quad(f,0,10,args = c)[0]
result.append(integral)
return result
if __name__ == "__main__":
c_list = np.linspace(0,20,200)
plt.plot(c_list, getIntegral(c_list))
plt.show()

Plotting a custom function that returns an array of floats

I have my custom function in python3 as follows:
myFunction(A, x)
"""
Args:
A (list)
x (float)
Returns:
Y: numpy array of floats [y1,y2,...,y(len(A))]
"""
return Y
What I want to do is to make a plot for some chosen constant list A, where the X axis is the input argument x (ranging between some values, say 0,10) and on the Y axis are the floats in the output array (so multiple curves, in different colors)
I was thinking of doing something like this
import matplotlib.pyplot as plt
A = [5,10,15,20]
x = numpy.linspace(0,10,1000) #1000 numbers between 0 and 10
plt.plot(x,myFunction(A, x))
But I'm getting the error
TypeError: only size-1 arrays can be converted to Python scalars
Thanks
It looks like I eventually found the way
x = np.linspace(0,100,1001)
resultSet = [] #initialize list to store results
for i in range(0, len(x)):
resultSet.append(list(myFunction(A, x)))
resCount = len(resultSet[0])
labelList = [] #initialize list for legend names
for i in range(0,resCount):
labelList.append("Line "+str(i+1))
lineObjects = plt.plot(list(x),resultSet)
plt.xlabel("x label")
plt.ylabel("y label")
plt.legend(lineObjects,labelList)
plt.show()

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