def efficient_frontier(self, model="Classic", rm="MV", points=20, rf=0, hist=True):
r"""
Method that calculates several portfolios in the efficient frontier
of the selected risk measure, available with current assets and
constraints.
Parameters
----------
model : str, optional
Methodology used to estimate input parameters.
The default is 'Classic'.
rm : str, optional
Risk measure used by the optimization model. The default is 'MV'.
points : scalar, optional
Number of point calculated from the efficient frontier.
The default is 50.
rf : scalar, optional
Risk free rate. The default is 0.
hist : bool, optional
Indicate if uses historical or factor estimation of returns to
calculate risk measures that depends on scenarios (All except
'MV' risk measure). The default is True.
Returns
-------
frontier : DataFrame
A dataframe that containts the weights of the portfolios.
Notes
-----
It's recommendable that don't use this method when there are too many
assets (more than 100) and you are using a scenario based risk measure
(all except standard deviation). It's preferable to use frontier_limits
method (faster) to know the range of expected return and expected risk.
"""
mu = None
sigma = None
returns = None
if model == "Classic":
mu = np.matrix(self.mu)
sigma = np.matrix(self.cov)
returns = np.matrix(self.returns)
nav = np.matrix(self.nav)
elif model == "FM":
mu = np.matrix(self.mu_fm)
if hist == False:
sigma = np.matrix(self.cov_fm)
returns = np.matrix(self.returns_fm)
nav = np.matrix(self.nav_fm)
elif hist == True:
sigma = np.matrix(self.cov)
returns = np.matrix(self.returns)
nav = np.matrix(self.nav)
elif model == "BL":
mu = np.matrix(self.mu_bl)
if hist == False:
sigma = np.matrix(self.cov_bl)
elif hist == True:
sigma = np.matrix(self.cov)
returns = np.matrix(self.returns)
nav = np.matrix(self.nav)
elif model == "BL_FM":
mu = np.matrix(self.mu_bl_fm_2)
if hist == False:
sigma = np.matrix(self.cov_bl_fm_2)
returns = np.matrix(self.returns_fm)
nav = np.matrix(self.nav_fm)
elif hist == True:
sigma = np.matrix(self.cov)
returns = np.matrix(self.returns)
nav = np.matrix(self.nav)
alpha1 = self.alpha
limits = self.frontier_limits(model="Classic", rm=rm, rf=rf, hist=hist)
w_min = np.matrix(limits.iloc[:, 0]).T
w_max = np.matrix(limits.iloc[:, 1]).T
ret_min = (mu * w_min).item()
ret_max = (mu * w_max).item()
if rm == "MV":
risk_min = np.sqrt(w_min.T * sigma * w_min).item()
risk_max = np.sqrt(w_max.T * sigma * w_max).item()
elif rm == "MAD":
risk_min = rk.MAD(returns * w_min)
risk_max = rk.MAD(returns * w_max)
elif rm == "MSV":
risk_min = rk.SemiDeviation(returns * w_min)
risk_max = rk.SemiDeviation(returns * w_max)
elif rm == "CVaR":
risk_min = rk.CVaR_Hist(returns * w_min, alpha1)
risk_max = rk.CVaR_Hist(returns * w_max, alpha1)
elif rm == "WR":
risk_min = rk.WR(returns * w_min)
risk_max = rk.WR(returns * w_max)
elif rm == "FLPM":
risk_min = rk.LPM(returns * w_min, rf, 1)
risk_max = rk.LPM(returns * w_max, rf, 1)
elif rm == "SLPM":
risk_min = rk.LPM(returns * w_min, rf, 2)
risk_max = rk.LPM(returns * w_max, rf, 2)
elif rm == "MDD":
risk_min = rk.MaxAbsDD(returns * w_min)
risk_max = rk.MaxAbsDD(returns * w_max)
elif rm == "ADD":
risk_min = rk.AvgAbsDD(returns * w_min)
risk_max = rk.AvgAbsDD(returns * w_max)
elif rm == "CDaR":
risk_min = rk.ConAbsDD(returns * w_min, alpha1)
risk_max = rk.ConAbsDD(returns * w_max, alpha1)
mus = np.linspace(ret_min, ret_max + (ret_max - ret_min) / (points), points + 1)
risks = np.linspace(
risk_min, risk_max + (risk_max - risk_min) / (points), points + 1
)
risk_lims = [
"upperdev",
"uppermad",
"uppersdev",
"upperCVaR",
"upperwr",
"upperflpm",
"upperslpm",
"uppermdd",
"upperadd",
"upperCDaR",
]
risk_names = [
"MV",
"MAD",
"MSV",
"CVaR",
"WR",
"FLPM",
"SLPM",
"MDD",
"ADD",
"CDaR",
]
item = risk_names.index(rm)
frontier = []
n = 0
for i in range(len(risks)):
try:
if n == 0:
w = self.optimization(
model=model, rm=rm, obj="MinRisk", rf=rf, l=0, hist=hist
)
else:
setattr(self, risk_lims[item], risks[i])
w = self.optimization(
model=model, rm=rm, obj="MaxRet", rf=rf, l=0, hist=hist
)
n += 1
frontier.append(w)
except:
pass
setattr(self, risk_lims[item], None)
frontier = pd.concat(frontier, axis=1)
frontier.columns = list(range(len(risks)))
return frontier
def plot_drawdown(nav, w, alpha=0.01, height=8, width=10, ax=None):
r"""
Create a chart with the evolution of portfolio prices and drawdown.
Parameters
----------
nav : DataFrame
Cumulative assets returns.
w : DataFrame, optional
A portfolio specified by the user to compare with the efficient
frontier. The default is None.
alpha : float, optional
Significante level of VaR, CVaR and CDaR. The default is 0.01.
height : float, optional
Height of the image in inches. The default is 8.
width : float, optional
Width of the image in inches. The default is 10.
ax : matplotlib axis, optional
If provided, plot on this axis. The default is None.
Raises
------
ValueError
When the value cannot be calculated.
Returns
-------
ax : matplotlib axis.
Returns the Axes object with the plot for further tweaking.
Example
-------
::
nav=port.nav
ax = plf.plot_drawdown(nav=nav, w=w1, alpha=0.01, height=8, width=10, ax=None)
.. image:: images/Drawdown.png
"""
if not isinstance(nav, pd.DataFrame):
raise ValueError("data must be a DataFrame")
if not isinstance(w, pd.DataFrame):
raise ValueError("w must be a DataFrame")
if w.shape[1] > 1 and w.shape[0] == 0:
w = w.T
elif w.shape[1] > 1 and w.shape[0] > 0:
raise ValueError("w must be a DataFrame")
if nav.shape[1] != w.shape[0]:
a1 = str(nav.shape)
a2 = str(w.shape)
raise ValueError("shapes " + a1 + " and " + a2 + " not aligned")
if ax is None:
fig = plt.gcf()
ax = fig.subplots(nrows=2, ncols=1)
ax = ax.flatten()
fig.set_figwidth(width)
fig.set_figheight(height)
index = nav.index.tolist()
a = np.array(nav, ndmin=2)
a = np.insert(a, 0, 0, axis=0)
a = np.diff(a, axis=0)
a = np.array(a, ndmin=2) @ np.array(w, ndmin=2)
prices = 1 + np.insert(a, 0, 0, axis=0)
prices = np.cumprod(prices, axis=0)
prices = np.ravel(prices).tolist()
prices2 = 1 + np.array(np.cumsum(a, axis=0))
prices2 = np.ravel(prices2).tolist()
del prices[0]
DD = []
peak = -99999
for i in range(0, len(prices)):
if prices2[i] > peak:
peak = prices2[i]
DD.append((peak - prices2[i]))
DD = -np.array(DD)
titles = [
"Historical Compounded Cumulative Returns",
"Historical Uncompounded Drawdown",
]
data = [prices, DD]
color1 = ["b", "orange"]
risk = [-rk.MaxAbsDD(a), -rk.AvgAbsDD(a), -rk.ConAbsDD(a, alpha)]
label = [
"Maximum Drawdown: " + "{0:.2%}".format(risk[0]),
"Average Drawdown: " + "{0:.2%}".format(risk[1]),
"{0:.2%}".format((1 - alpha))
+ " Confidence CDaR: "
+ "{0:.2%}".format(risk[2]),
]
color2 = ["r", "limegreen", "fuchsia"]
j = 0
ymin = np.min(DD) * 1.4
for i in ax:
i.clear()
i.plot_date(index, data[j], "-", color=color1[j])
if j == 1:
i.fill_between(index, 0, data[j], facecolor=color1[j], alpha=0.3)
for k in range(0, 3):
i.axhline(y=risk[k], color=color2[k], linestyle="-", label=label[k])
i.set_ylim(ymin, 0)
i.legend(loc="lower right") # , fontsize = 'x-small')
i.set_title(titles[j])
i.set_yticklabels(["{:3.2%}".format(x) for x in i.get_yticks()])
i.grid(linestyle=":")
j = j + 1
fig = plt.gcf()
fig.tight_layout()
return ax
