1 | \form#0:$A=\frac{df}{dx}|_{x0,u0}$ |
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2 | \form#1:$A=\frac{d}{dx}f(x,u)|_{x0,u0}$ |
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3 | \form#2:$A=\frac{d}{du}f(x,u)|_{x0,u0}$ |
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4 | \form#3:$x \sim epdf(rv)$ |
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5 | \form#4:\[ f(x|a,b) = \prod f(x_i|a_i,b_i) \] |
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6 | \form#5:\[M = L'DL\] |
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7 | \form#6:\[ x_t = A x_{t-1} + B u_t + Q^{1/2} e_t \] |
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8 | \form#7:\[ y_t = C x_{t-1} + C u_t + Q^{1/2} w_t. \] |
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9 | \form#8:\[ f(x|\alpha,\beta) = \prod f(x_i|\alpha_i,\beta_i) \] |
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10 | \form#9:$x^{(i)}, i=1..n$ |
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11 | \form#10:$x \sim epdf(rv|cond)$ |
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12 | \form#11:$\alpha=k$ |
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13 | \form#12:$\beta=k/\mu$ |
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14 | \form#13:$\mu/\sqrt(k)$ |
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15 | \form#14:$\mu$ |
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16 | \form#15:$\alpha$ |
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17 | \form#16:$\beta$ |
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18 | \form#17:\[ \left[\begin{array}{cc} R^{0.5}\\ P_{t|t-1}^{0.5}C' & P_{t|t-1}^{0.5}CA'\\ & Q^{0.5}\end{array}\right]<\mathrm{orth.oper.}>=\left[\begin{array}{cc} R_{y}^{0.5} & KA'\\ & P_{t+1|t}^{0.5}\\ \\\end{array}\right]\] |
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19 | \form#18:\[ \mu = \mu_{t-1} ^{l} p^{1-l}\] |
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20 | \form#19:$A=Ch' Ch$ |
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21 | \form#20:$Ch$ |
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22 | \form#21:$L$ |
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23 | \form#22:$D$ |
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24 | \form#23:$V = V + w v v'$ |
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25 | \form#24:$C$ |
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26 | \form#25:$V = C*V*C'$ |
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27 | \form#26:$V = C'*V*C$ |
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28 | \form#27:$V$ |
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29 | \form#28:$x$ |
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30 | \form#29:$x= v'*V*v$ |
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31 | \form#30:$x= v'*inv(V)*v$ |
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32 | \form#31:$U$ |
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33 | \form#32:$A'D0 A$ |
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34 | \form#33:$L'DL$ |
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35 | \form#34:$A'*diag(D)*A = self.L'*diag(self.D)*self.L$ |
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36 | \form#35:$f(x)$ |
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37 | \form#36:$f(rv|rvc,data)$ |
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38 | \form#37:$x=$ |
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39 | \form#38:$t$ |
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40 | \form#39:$t+1$ |
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41 | \form#40:$mu=A*rvc$ |
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42 | \form#41:$k$ |
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43 | \form#42:$p$ |
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44 | \form#43:$l$ |
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45 | \form#44:$w$ |
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46 | \form#45:$f(x) = a$ |
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47 | \form#46:$f(x) = Ax+B$ |
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48 | \form#47:$f(x,u)$ |
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49 | \form#48:$f(x,u) = Ax+Bu$ |
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50 | \form#49:$f(x0,u0)$ |
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51 | \form#50:$u$ |
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52 | \form#51:$[\theta r]$ |
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53 | \form#52:$\psi=\psi(y_{1:t},u_{1:t})$ |
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54 | \form#53:$u_t$ |
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55 | \form#54:$e_t$ |
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56 | \form#55:$\theta_t,r_t$ |
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57 | \form#56:$\in <0,1>$ |
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58 | \form#57:$\theta,r$ |
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59 | \form#58:$dt = [y_t psi_t] $ |
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60 | \form#59:$epdf(rv)$ |
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61 | \form#60:$\mathcal{I}$ |
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62 | \form#61:\[ y_t = \theta_1 \psi_1 + \theta_2 + \psi_2 +\ldots + \theta_n \psi_n + r e_t \] |
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63 | \form#62:\[ e_t \sim \mathcal{N}(0,1). \] |
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64 | \form#63:\[ f(x) = \sum_{i=1}^{n} w_{i} f_i(x), \quad \sum_{i=1}^n w_i = 1. \] |
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65 | \form#64:$f_i(x)$ |
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66 | \form#65:$\omega$ |
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67 | \form#66:\[ f(y_t|\psi_t, \Theta) = \sum_{i=1}^{n} w_i f(y_t|\psi_t, \theta_i) \] |
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68 | \form#67:$\psi$ |
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69 | \form#68:$w=[w_1,\ldots,w_n]$ |
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70 | \form#69:$\theta_i$ |
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71 | \form#70:$\Theta$ |
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72 | \form#71:$\Theta = [\theta_1,\ldots,\theta_n,w]$ |
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73 | \form#72:$p\times$ |
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74 | \form#73:$n$ |
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75 | \form#74:\[ f(x|\beta) = \frac{\Gamma[\gamma]}{\prod_{i=1}^{n}\Gamma(\beta_i)} \prod_{i=1}^{n}x_i^(\beta_i-1) \] |
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76 | \form#75:$\gamma=\sum_i beta_i$ |
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77 | \form#76:\[ f(x|\beta) = \frac{\Gamma[\gamma]}{\prod_{i=1}^{n}\Gamma(\beta_i)} \prod_{i=1}^{n}x_i^{\beta_i-1} \] |
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78 | \form#77:$\gamma=\sum_i \beta_i$ |
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79 | \form#78:$mu=A*rvc+mu_0$ |
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80 | \form#79:\[ f(rv|rvc) = \frac{f(rv,rvc)}{f(rvc)} \] |
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81 | \form#80:$ f(rvc) = \int f(rv,rvc) d\ rv $ |
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82 | \form#81:\[ f(\theta|D) =\frac{f(D|\theta)f(\theta)}{f(D)}\] |
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83 | \form#82:$ \theta $ |
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84 | \form#83:$ D $ |
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85 | \form#84:$ f(D|\theta) $ |
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86 | \form#85:$ f(\theta) $ |
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87 | \form#86:$ f(D) $ |
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88 | \form#87:$\alpha=\mu/k+2$ |
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89 | \form#88:$\beta=\mu(\alpha-1)$ |
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90 | \form#89:\[ f(a,b,c) = f(a|b,c) f(b) f(c) \] |
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91 | \form#90:$ f(a|b,c) $ |
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92 | \form#91:$ f(b) $ |
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93 | \form#92:$ f(c) $ |
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94 | \form#93:\[ x\sim iG(a,b) => 1/x\sim G(a,1/b) \] |
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95 | \form#94:$y_t$ |
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96 | \form#95:$[\theta,\rho]$ |
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97 | \form#96:$\phi_t$ |
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98 | \form#97:$\mathcal{N}(0,1)$ |
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99 | \form#98:$\phi$ |
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100 | \form#99:\[ y_t = \theta' \phi_t + \rho e_t \] |
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101 | \form#100:$[u_t, y_{t-1 }, u_{t-1}, \ldots]$ |
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102 | \form#101:\[ y_t = \theta' \psi_t + \rho e_t \] |
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103 | \form#102:$\psi_t$ |
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104 | \form#103:$[y_t, u_t, y_{t-1 }, u_{t-1}, \ldots]$ |
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105 | \form#104:$ f(x_t|x_{t-1}) $ |
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106 | \form#105:$ f(d_t|x_t) $ |
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107 | \form#106:$ x $ |
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108 | \form#107:$ f_x()$ |
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109 | \form#108:$ [x_1 , x_2 , \ldots \ $ |
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110 | \form#109:$ f_x(rv)$ |
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111 | \form#110:$ t $ |
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112 | \form#111:$ t+1 $ |
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113 | \form#112:$ f(d_{t+1} |d_{t}, \ldots d_{0}) $ |
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114 | \form#113:$ \mu $ |
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115 | \form#114:$ k $ |
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116 | \form#115:$ \alpha=\mu/k^2+2 $ |
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117 | \form#116:$ \beta=\mu(\alpha-1)$ |
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118 | \form#117:$ \mu/\sqrt(k)$ |
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119 | \form#118:$ y_t $ |
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120 | \form#119:$ dt = [y_t psi_t] $ |
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121 | \form#120:$ [d_1, d_2, \ldots d_t] $ |
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122 | \form#121:\begin{eqnarray} x_t &= &A x_{t-1} + B u_{t} + v_t,\\ y_t &= &C x_{t} + D u_{t} + w_t, \end{eqnarray} |
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123 | \form#122:$ x_t $ |
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124 | \form#123:$ A, B, C, D$ |
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125 | \form#124:$v_t, w_t$ |
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126 | \form#125:$Q, R\$, respectively. Both prior and posterior densities on the state are Gaussian, i.e. of the class enorm. There is a range of classes that implements this functionality, namely: - KalmanFull which implements the estimation algorithm on full matrices, - KalmanCh which implements the estimation algorithm using choleski decompositions and QR algorithm. \section ekf Extended Kalman Filtering Extended Kalman filtering arise by linearization of non-linear state space model: \f{eqnarray} x_t &= &g( x_{t-1}, u_{t}) + v_t,\\ y_t &= &h( x_{t} , u_{t}) + w_t, \f} where $ |
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127 | \form#126:$Q, R$ |
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128 | \form#127:\begin{eqnarray} x_t &= &g( x_{t-1}, u_{t}) + v_t,\\ y_t &= &h( x_{t} , u_{t}) + w_t, \end{eqnarray} |
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129 | \form#128:$ g(), h() $ |
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130 | \form#129:\[ V_t = \sum_{i=0}^{n} \left[\begin{array}{c}y_{t}\\ \psi_{t}\end{array}\right] \begin{array}{c} [y_{t}',\,\psi_{t}']\\ \\\end{array} \] |
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131 | \form#130:\[ \nu_t = \sum_{i=0}^{n} 1 \] |
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132 | \form#131:$ \theta_t , r_t $ |
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133 | \form#132:\[ V_t = V_{t-1} + \phi \left[\begin{array}{c}y_{t}\\ \psi_{t}\end{array}\right] \begin{array}{c} [y_{t}',\,\psi_{t}']\\ \\\end{array} +(1-\phi) V_0 \] |
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134 | \form#133:\[ \nu_t = \nu_{t-1} + \phi + (1-\phi) \nu_0 \] |
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135 | \form#134:$ \phi $ |
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136 | \form#135:$ \phi \in [0,1]$ |
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137 | \form#136:\[ \mathrm{win_length} = \frac{1}{1-\phi}\] |
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138 | \form#137:$ \phi=0.9 $ |
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139 | \form#138:$ V_0 , \nu_0 $ |
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140 | \form#139:$ V_t , \nu_t $ |
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141 | \form#140:$ \phi<1 $ |
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