analistica/slides/sections/7.md

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MC simulations

In summary


              Landau            Moyal

median m_L\ex m_M\ex (μ, σ)

mode \mu_L\ex \mu_M\ex (μ)

FWHM w_L\ex w_M\ex (σ)

Moyal parameters

A M(x) similar to L(x) can be found by imposing:

\vspace{15pt}

  • equal mode

  \mu_M\ex = \mu_L\ex \thus \mu \approx 0.22278298...

. . .

  • equal width

  w_M\ex = w_L\ex = \sigma \cdot a \thus \sigma \approx 1.1191486...

Moyal parameters

:::: {.columns} ::: {.column width=50%} :::

::: {.column width=50%} ::: ::::

Moyal parameters

This leads to more different medians:

\begin{align*} m_M = 0.787... \thus &m_M = 0.658... \ &m_L = 1.355... \end{align*}

Landau Sample

Sample N random points following L(x)


  L(x) = \frac{1}{\pi} \int \limits_{0}^{+ \infty}
         dt \, e^{-t \ln(t) -xt} \sin (\pi t)

. . .

gsl_ran_Landau(gsl_rng)

Moyal sample

Sample N random points following M_{\mu \sigma}(x)


  M_{\mu \sigma}(x) = \frac{1}{\sqrt{2 \pi} \sigma} \exp
         \left[ - \frac{1}{2} \left(
           \frac{x - \mu}{\sigma}
           + e^{-\frac{x - \mu}{\sigma}} \right) \right]

. . .

reverse sampling

  • sampling y uniformly in [0, 1] \hence x = Q_M(y)