Plot friction force vs. angle
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import numpy as np | |
# Triginometry {{{ | |
def cos(x): return round( np.cos( np.radians(x) ), 10 ) | |
def sin(x): return round( np.sin( np.radians(x) ), 10 ) | |
def tg(x): return round( np.tan( np.radians(x) ), 10 ) | |
def arctg(x): return np.degrees( np.arctan(x) ) | |
def sins(x): return round( np.sin( np.radians(x) )**2, 10 ) | |
def asin(x): return np.degrees( np.arcsin(x) ) | |
#}}} | |
def sqrt(x): return x**(1./2) | |
# Plot setup {{{ | |
from matplotlib import pyplot as plt | |
from matplotlib import rc, rcParams | |
rcParams['font.size'] = 20. | |
rcParams['text.usetex'] = True | |
#rc('text.latex', preamble=r'\usepackage{esvect}') | |
rcParams['font.sans-serif'] = ['Computer Modern'] | |
rc('text.latex', preamble=r'\usepackage[T2A]{fontenc} \usepackage[utf8]{inputenc} \usepackage{bm}') | |
#rc('text.latex', preamble=r'\usepackage[utf8]{inputenc}') | |
rc('axes', linewidth=1.2) | |
rc('xtick.major', size=4, width=1.1) | |
rc('ytick.major', size=4, width=1.1) | |
fig, ax = plt.subplots(figsize=(8,8)) | |
fig.subplots_adjust(left=.15, bottom=.15, right=.95, top=.83) | |
#}}} | |
# Initial parameters (SI units) | |
m = 1 | |
g = 10 | |
mu = tg(35) | |
alpha = np.linspace(0, 90, 1500) | |
mus = np.linspace(0, 1.5, 500) | |
for mu in mus: | |
Ftr=[] | |
for a in alpha: | |
if mu > tg(a): | |
Ftr = np.append(Ftr, m*g*sin(a)) | |
else: | |
Ftr = np.append(Ftr, mu*m*g*cos(a)) | |
ax.set_xlim([0,90]) | |
ax.set_ylim([0,10.5]) | |
ax.set_xlabel('$\\alpha$ [$^{\\circ}$]') | |
ax.set_ylabel('$F_\\textrm{тр}$ [\\textrm{Н}]') | |
ax.plot(alpha, Ftr, lw=2.5, label='$F_\\textrm{тр}$', zorder=4) | |
# Add mu=... to the legend | |
ax.plot([], [], ' ', label='$\\mu={}$'.format("{:.2f}".format(mu) ) ) | |
# Plot full mgsina | |
Ftr=[] | |
for a in alpha: | |
Ftr = np.append(Ftr, m*g*sin(a)) | |
ax.plot(alpha, Ftr, ':', label='$mg\\sin{\\alpha}$', c='orange') | |
# Plot full μmgcosa | |
Ftr=[] | |
for a in alpha: | |
Ftr = np.append(Ftr, mu*m*g*cos(a)) | |
ax.plot(alpha, Ftr, '--', label='$\\mu mg\\cos{\\alpha}$', c='green') | |
ax.set_axisbelow(True) | |
ax.grid() | |
ax.legend(loc='upper center', bbox_to_anchor=(0.5, 1.23), shadow=True, ncol=2) | |
plt.savefig('plots/' + str(mu)+'.pdf', bbox_inches='tight') | |
plt.cla() | |
#plt.show() | |
# convert -delay 0.01 -loop 0 *.pdf ftr_a_mu.gif |
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