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calc_spatial_lag [2011/07/26 18:52] hermann created |
calc_spatial_lag [2026/08/28 03:11] (current) hermann Sync from local documentation review |
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| - | ====== Calc Spatial Lag ====== | + | ====== Calc Spatial Lag ====== |
| ===== Description ===== | ===== Description ===== | ||
| - | This functor iteratively solves a spatial lag regression. | + | Container that iteratively solves a spatial lag regression, y = pLag * W * y + X * B + E, over independent variables registered inside it. |
| ===== Inputs ===== | ===== Inputs ===== | ||
| - | ^ Name ^ Type ^ Description ^ | + | ^ Name ^ Type ^ Description ^ |
| - | | P Lag | [[Double Type|Double ]] | pLag is the autoregressive coefficient. | | + | | P Lag | [[Real Value Type]] | Spatial autoregressive coefficient (p) used in the regression. | |
| - | | W Neighborhoods | [[Neighborhood Table Type|Neighborhood Table ]] | The neighborhood matrix. | | + | | W Neighborhoods | [[Neighborhood Table Type]] | Spatial weight matrix (W) used in the regression. | |
| - | | X1 | [[Lookup Table Type|Lookup Table ]] | x1 is the autoregressive term. When y is not known, x1 is used instead. In this case, a lookup table with same number of records and values equal to zero must be reported. | | + | | X1 | [[Lookup Table Type]] | Values of the observed dependent variable (X1) for each region. When the observed result is not yet known, X1 stands in for it; in that case, supply a lookup table with the same number of records and every value set to zero. | |
| - | | B Coefficients | [[Lookup Table Type|Lookup Table ]] | Coefficients for independent variables x2, x3, x4... xn. | | + | | B Coefficients | [[Lookup Table Type]] | Regression coefficients (B): the coefficient of the observed variable (index 0), followed by the coefficient of each independent variable registered in this container. | |
| - | | E Error | [[Double Type|Double ]] | Regression random error term. | | + | | E Error | [[Real Value Type]] | Random error term (E) of the regression. | |
| - | ===== Output ===== | + | ===== Optional Inputs ===== |
| - | ^ Name ^ Type ^ Description ^ | + | None. |
| - | | Y Result | [[Lookup Table Type|Lookup Table ]] | A lookup table with Y results. | | + | |
| - | | Y Predicted Result | [[Lookup Table Type|Lookup Table ]] | A lookup table with the predicted results. | | + | ===== Outputs ===== |
| + | |||
| + | ^ Name ^ Type ^ Description ^ | ||
| + | | Y Result | [[Lookup Table Type]] | Result (y) of the equation y = pLag * W * y + X * B + E, solved iteratively until convergence. | | ||
| + | | Y Predicted Result | [[Lookup Table Type]] | Predicted result (y^) of the equation y^ = pLag * W * X1 + X * B + E. | | ||
| ===== Group ===== | ===== Group ===== | ||
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| ===== Notes ===== | ===== Notes ===== | ||
| - | The lag spatial model is represented as follows: | + | The independent variables (X) used in the regression are registered inside this container by functors representing a numbered table (Number Table), each identified by a sequential number starting at 1. |
| - | <m>y = {rho W y}+{X beta}+ varepsilon</m> | + | The number of coefficients supplied in B Coefficients must equal the number of independent variables registered in this container, plus one for the observed variable's own coefficient (index 0). |
| - | where <m>rho</m> is the autoregressive coefficient; W is the spatial weight matrix; y is the dependent variable; X is co-variables' information matrix; <m>beta</m> is the regression coefficients and <m>varepsilon</m> is a random error term. W can be understood as the representation of the spatial interaction of a phenomenon. In a binary matrix, unit i is unit j’s neighbor if the spatial weight matrix cell, a<sub>ij</sub>, is equal to 1. | + | W represents the spatial interaction of a phenomenon: in a binary weight matrix, unit i is a neighbor of unit j when the corresponding matrix cell is 1. |
| - | ==== References ==== | + | **References** |
| - | ANSELIN, L. SpaceStat TUTORIAL. Urbana-Champaign, University of Illinois, 1992. | + | ANSELIN, L. SpaceStat Tutorial. Urbana-Champaign, University of Illinois, 1992. |
| ANSELIN, L. Spatial Externalities, Spatial Multipliers and Spatial Econometrics. Urbana-Champaign, University of Illinois, 2002. | ANSELIN, L. Spatial Externalities, Spatial Multipliers and Spatial Econometrics. Urbana-Champaign, University of Illinois, 2002. | ||