Jump diffusion and hestonj use the same parameters

Author: lsbardel

.vscode/launch.json

@@ -14,7 +14,7 @@
             "args": [
                 "-x",
                 "-vvv",
-                "quantflow_tests/test_utils.py",
+                "quantflow_tests/test_jump_diffusion.py",
             ]
         },
     ]

notebooks/api/sp/jump_diffusion.rst

@@ -14,11 +14,3 @@ The most famous jump-diffusion model is the Merton model, which was introduced b
    :member-order: groupwise
    :autosummary:
    :autosummary-nosignatures:
-
-
-
-.. autoclass:: Merton
-   :members:
-   :member-order: groupwise
-   :autosummary:
-   :autosummary-nosignatures:

notebooks/examples/heston_vol_surface.md

@@ -11,21 +11,24 @@ kernelspec:
   name: python3
 ---
 
-# Heston Volatility Surface
+# HestonJ Volatility Surface
 
-Here we study the Implied volatility surface of the Heston model. The Heston model is a stochastic volatility model that is widely used in the finance industry to price options.
+Here we study the Implied volatility surface of the Heston model with jumps.
+The Heston model is a stochastic volatility model that is widely used in the finance industry to price options.
 
 ```{code-cell} ipython3
 from quantflow.sp.heston import HestonJ
+from quantflow.utils.distributions import DoubleExponential
 from quantflow.options.pricer import OptionPricer
 
-pricer = OptionPricer(model=HestonJ.exponential(
+pricer = OptionPricer(model=HestonJ.create(
+    DoubleExponential,
     vol=0.5,
     kappa=2,
-    rho=0.0,
-    sigma=0.6,
+    rho=-0.2,
+    sigma=0.8,
     jump_fraction=0.5,
-    jump_asymmetry=1.0
+    jump_asymmetry=0.2
 ))
 pricer
 ```

notebooks/models/bns.md

@@ -28,7 +28,7 @@ This means that the characteristic function of $y_t$ can be represented as
     &= {\mathbb E}\left[\exp{\left(-\tau_t \phi_{w, u} + i u \rho z_{\kappa t}\right)}\right]
 \end{align}
 
-$\phi_{w, u}$ is the characteristic exponent of $w_1$. The second equivalence is a consequence of $w$ and $\tau$ being independent, as discussed in [the time-changed Lévy](./levy.md) process section.
+$\phi_{w, u}$ is the characteristic exponent of $w_1$. The second equivalence is a consequence of $w$ and $\tau$ being independent, as discussed in [the time-changed Lévy](../theory/levy.md) process section.
 
 ```{code-cell}
 from quantflow.sp.bns import BNS

notebooks/models/heston.md

@@ -7,7 +7,7 @@ jupytext:
     format_version: 0.13
     jupytext_version: 1.16.6
 kernelspec:
-  display_name: Python 3 (ipykernel)
+  display_name: .venv
   language: python
   name: python3
 ---
@@ -31,20 +31,20 @@ This means that the characteristic function of $y_t=x_{\tau_t}$ can be represent
      &= e^{-a_{t,u} - b_{t,u} \nu_0}
 \end{align}
 
-```{code-cell}
+```{code-cell} ipython3
 from quantflow.sp.heston import Heston
 pr = Heston.create(vol=0.6, kappa=2, sigma=1.5, rho=-0.1)
 pr
 ```
 
-```{code-cell}
+```{code-cell} ipython3
 # check that the variance CIR process is positive
 pr.variance_process.is_positive, pr.variance_process.marginal(1).std()
 ```
 
 ## Characteristic Function
 
-```{code-cell}
+```{code-cell} ipython3
 from quantflow.utils import plot
 m = pr.marginal(0.1)
 plot.plot_characteristic(m)
@@ -58,26 +58,26 @@ The immaginary part of the characteristic function is given by the correlation c
 
 Here we compare the marginal distribution at a time in the future $t=1$ with a normal distribution with the same standard deviation.
 
-```{code-cell}
+```{code-cell} ipython3
 plot.plot_marginal_pdf(m, 128, normal=True, analytical=False)
 ```
 
 Using log scale on the y axis highlighs the probability on the tails much better
 
-```{code-cell}
+```{code-cell} ipython3
 plot.plot_marginal_pdf(m, 128, normal=True, analytical=False, log_y=True)
 ```
 
 ## Option pricing
 
-```{code-cell}
+```{code-cell} ipython3
 from quantflow.options.pricer import OptionPricer
 from quantflow.sp.heston import Heston
 pricer = OptionPricer(Heston.create(vol=0.6, kappa=2, sigma=0.8, rho=-0.2))
 pricer
 ```
 
-```{code-cell}
+```{code-cell} ipython3
 import plotly.express as px
 import plotly.graph_objects as go
 from quantflow.options.bs import black_call
@@ -89,7 +89,7 @@ fig.add_trace(go.Scatter(x=r.moneyness_ttm, y=b.time_value, name=b.name, line=di
 fig.show()
 ```
 
-```{code-cell}
+```{code-cell} ipython3
 fig = None
 for ttm in (0.05, 0.1, 0.2, 0.4, 0.6, 1):
     fig = pricer.maturity(ttm).plot(fig=fig, name=f"t={ttm}")
@@ -102,17 +102,17 @@ The simulation of the Heston model is heavily dependent on the simulation of the
 
 The code implements algorithms from {cite:p}heston-simulation
 
-```{code-cell}
+```{code-cell} ipython3
 from quantflow.sp.heston import Heston
 pr = Heston.create(vol=0.6, kappa=2, sigma=0.8, rho=-0.4)
 pr
 ```
 
-```{code-cell}
+```{code-cell} ipython3
 pr.sample(20, time_horizon=1, time_steps=1000).plot().update_traces(line_width=0.5)
 ```
 
-```{code-cell}
+```{code-cell} ipython3
 import pandas as pd
 from quantflow.utils import plot
 
@@ -122,12 +122,12 @@ df = pd.DataFrame(mean, index=paths.time)
 plot.plot_lines(df)
 ```
 
-```{code-cell}
+```{code-cell} ipython3
 std = dict(std=pr.marginal(paths.time).std(), simulated=paths.std())
 df = pd.DataFrame(std, index=paths.time)
 plot.plot_lines(df)
 ```
 
-```{code-cell}
+```{code-cell} ipython3
 
 ```

notebooks/models/heston_jumps.md

@@ -30,41 +30,49 @@ where $j_t$ is a double exponential Compound Poisson process which adds three ad
 * the jump percentage (fraction) contribution to the total variance
 * the jump asymmetry is defined as a parameter greater than 0; 1 means jump are symmetric
 
-The jump process is independent of the other Brownian motions.
+The jump process is independent from the Brownian motions. See [HestonJ](../api/sp/heston.rst#quantflow.sp.heston.HestonJ) for python
+API documentation.
 
 ```{code-cell} ipython3
 from quantflow.sp.heston import HestonJ
-pr = HestonJ.exponential(
+from quantflow.utils.distributions import DoubleExponential
+pr = HestonJ.create(
+    DoubleExponential,
     vol=0.6,
     kappa=2,
     sigma=0.8,
-    rho=-0.2,
+    rho=-0.0,
     jump_intensity=50,
     jump_fraction=0.2,
-    jump_asymmetry=1.2
+    jump_asymmetry=0.0
 )
 pr
 ```
 
 ```{code-cell} ipython3
 from quantflow.utils import plot
-plot.plot_marginal_pdf(pr.marginal(0.1), 128, normal=True, analytical=False)
+plot.plot_marginal_pdf(pr.marginal(0.5), 128, normal=True, analytical=False)
 ```
 
 ```{code-cell} ipython3
 from quantflow.options.pricer import OptionPricer
-from quantflow.sp.heston import Heston
 pricer = OptionPricer(pr)
 pricer
 ```
 
 ```{code-cell} ipython3
+
 fig = None
 for ttm in (0.05, 0.1, 0.2, 0.4, 0.6, 1):
+
     fig = pricer.maturity(ttm).plot(fig=fig, name=f"t={ttm}")
 fig.update_layout(title="Implied black vols", height=500)
 ```
 
 ```{code-cell} ipython3
 
 ```
+
+```{code-cell} ipython3
+
+```

notebooks/models/jump_diffusion.md

@@ -6,7 +6,7 @@ jupytext:
     format_version: 0.13
     jupytext_version: 1.16.6
 kernelspec:
-  display_name: Python 3 (ipykernel)
+  display_name: .venv
   language: python
   name: python3
 ---
@@ -17,47 +17,52 @@ The library allows to create a vast array of jump-diffusion models. The most fam
 
 ## Merton Model
 
-```{code-cell}
-from quantflow.sp.jump_diffusion import Merton
+```{code-cell} ipython3
+from quantflow.sp.jump_diffusion import JumpDiffusion
+from quantflow.utils.distributions import Normal
 
-pr = Merton.create(diffusion_percentage=0.2, jump_intensity=50, jump_skew=-0.5)
-pr
+merton = JumpDiffusion.create(Normal, jump_fraction=0.8, jump_intensity=50)
 ```
 
 ### Marginal Distribution
 
-```{code-cell}
-m = pr.marginal(0.02)
+```{code-cell} ipython3
+m = merton.marginal(0.02)
 m.std(), m.std_from_characteristic()
 ```
 
-```{code-cell}
+```{code-cell} ipython3
+m2 = jd.marginal(0.02)
+m2.std(), m2.std_from_characteristic()
+```
+
+```{code-cell} ipython3
 from quantflow.utils import plot
 
 plot.plot_marginal_pdf(m, 128, normal=True, analytical=False, log_y=True)
 ```
 
 ### Characteristic Function
 
-```{code-cell}
+```{code-cell} ipython3
 plot.plot_characteristic(m)
 ```
 
 ### Option Pricing
 
 We can price options using the `OptionPricer` tooling.
 
-```{code-cell}
+```{code-cell} ipython3
 from quantflow.options.pricer import OptionPricer
-pricer = OptionPricer(pr)
+pricer = OptionPricer(merton)
 pricer
 ```
 
-```{code-cell}
+```{code-cell} ipython3
 fig = None
 for ttm in (0.05, 0.1, 0.2, 0.4, 0.6, 1):
     fig = pricer.maturity(ttm).plot(fig=fig, name=f"t={ttm}")
-fig.update_layout(title="Implied black vols", height=500)
+fig.update_layout(title="Implied black vols - Merton", height=500)
 ```
 
 This term structure of volatility demostrates one of the principal weakness of the Merton's model, and indeed of all jump diffusion models based on Lévy processes, namely the rapid flattening of the volatility surface as time-to-maturity increases.
@@ -67,14 +72,30 @@ For very short time-to-maturities, however, the model has no problem in producin
 
 ### MC paths
 
-```{code-cell}
-pr.sample(20, time_horizon=1, time_steps=1000).plot().update_traces(line_width=0.5)
+```{code-cell} ipython3
+merton.sample(20, time_horizon=1, time_steps=1000).plot().update_traces(line_width=0.5)
 ```
 
 ## Exponential Jump Diffusion
 
-This is a variation of the Mertoin model, where the jump distribution is a double exponential, one for the negative jumps and one for the positive jumps.
+This is a variation of the Mertoin model, where the jump distribution is a double exponential.
+The advantage of this model is that it allows for an asymmetric jump distribution, which can be useful in some cases, for example options prices with a skew.
+
+```{code-cell} ipython3
+from quantflow.utils.distributions import DoubleExponential
+
+jd = JumpDiffusion.create(DoubleExponential, jump_fraction=0.8, jump_intensity=50, jump_asymmetry=0.2)
+pricer = OptionPricer(jd)
+pricer
+```
+
+```{code-cell} ipython3
+fig = None
+for ttm in (0.05, 0.1, 0.2, 0.4, 0.6, 1):
+    fig = pricer.maturity(ttm).plot(fig=fig, name=f"t={ttm}")
+fig.update_layout(title="Implied black vols - Double-exponential Jump Diffusion ", height=500)
+```
+
+```{code-cell} ipython3
 
-```{code-cell}
-from 
 ```