Matrix of qualities |
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The matrix of qualities can contain spatially-continuous or spatially-discrete data. As an example of spatially-continuous data it can be: concentration of pollution, quantity of precipitations, a level of radiation. Value of these data from one cell to another one varies gradually, and their aggregate models some surface. As an example of spatially-discrete data it can be: type of vegetation, type of landed property, density of building, a territorial belonging. Value of spatially-discrete data at transition from one cell to another one remains the constants or varies by jump. Building matrix of qualities The call of dialog of building a matrix of qualities can be executed: - by means of New\Matrix of qualities item of File menu; - at addition of a nonexistent file by means of Add\ Matrix of qualities item of File menu; - at addition of a nonexistent file in Data list of map dialog.
Initial data for building a matrix of qualities can be: - objects of a vector map; - information of a database.
Format of initial data is specified in Data format window of Input data group. At building a matrix of qualities by a vector map it is necessary to set the model parameter - the semantic characteristic of numerical type which value will be requested from objects of a map. For a choice of the modelled parameter it is necessary to press ">>" button, located to the right of Model parameter window and to set the demanded semantic characteristic in Semantics dialog. At building a matrix of qualities by a vector map the objects data of the main map and of all user maps added to it are used. The matrix of qualities can be built onto region or onto the part of district specified in region. For building a matrix of qualities onto region it is necessary to include All region mode in Output area group. For building a matrix of qualities onto specified rectangular part of district it is necessary to press Select button in Output area group and to choose a part of district on a map by two pressing of the left mouse button. For change of borders of output area it is necessary to press Change button and to execute change by the mouse. For building a matrix onto the site of the district limited by the closed contour, it is necessary to press By contour button in Output area group and to set a contour by pressing of the left mouse button. The termination of a mode of the contour's specifying is the double pressing of the left mouse button. At building a matrix of qualities by a database it is necessary to set conformity of databases fields and X, Y, H coordinates (where X, Y - coordinates onto district in rectangular system, H - value of the modelled parameter). For specifying conformity of fields it is necessary to press ">>" button, located to the right of Data format window and to specify conformity in dialog: Selecting of fields from data base. The fields chosen from a database should be numerical. It is impossible to put into conformity the same field of a database to coordinates X, Y. In Surface building method window a calculation mode of values of matrix's elements is set. If the method Linear interpolation by net of triangles is chosen then the initial information can be dot data - dot objects of a vector map or dot measurements in a database. Thus by dot data the net of triangles is created, and then by this net of triangles the values of elements of a matrix are calculated. If Logarithmic interpolation method is chosen then the initial information can be dot, linear and area objects of a vector map. The elements located inside of area object, receive the value equal to value of the modelled parameter (semantics) of the given area object. During filling a matrix around of a defined element the local surface is created, by which the value of an element is calculated by method of logarithmic interpolation. The local surface is created by a set of the points nearest to the defined element. The set of points is formed from the metrics of dot and linear objects of a map. Values of the characteristic by which the surface is created, is choosing from the third coordinate (H) of object's metrics, and at absence of the third coordinate - from semantics of object (Modelled parameter field). At formation of a set of a points by the metrics of linear objects there is an opportunity of addition of intermediate points on pieces of the metrics which length exceeds the admission. Addition of intermediate points on pieces of the metrics of linear objects (structural lines) allows to increase influence of structural lines onto the form of a created surface. The admission is set in dialog: Setting of parameters - a field: Maximal length of a piece of the metrics without additional points Parameters of a method are set in Setting of parameters dialog (>> button). Parameters of a method are: - number of points for construction of a local surface around of a defined element (recommended values - from 30 up to 300, depending on density of points location; at increase of value of the given parameter the quality of a created surface improves, but construction is carried out more slowly), - number of the updated points for recalculation of a surface (recommended value is 5 - 10 % from the previous parameter, at decrease of value of the given parameter the quality of a surface improves, but recalculation of a surface occurs more often and construction is carried out more slowly), - maximal length in meters of a piece of the metrics of linear object (a structural line) without additional points (recommended value is k * ElemSize, where ElemSize - the side size of an element of a matrix, k - number from 5 up to 10; at decrease of value of the given parameter the influence of structural lines onto the form of a created surface due to addition of points on pieces of the metrics is increasing).
The quantity of points for building a local surface is set in Setting of parameters dialog - a field: Number of points for building a local surface around of a defined element. At transition to the next defined element in local area new points appears and a surface is rebuilt. The quantity of the added points at which recalculation of a surface is carried out, is set in Setting of parameters dialog - a field: Number of the updated points for recalculation of a surface. Setting up of palette of a created matrix of qualities can be executed by pressing ">>" button in Palette group. The minimal number of colors of a palette is equal 1, maximal - 256. The palette of a created matrix of qualities can be loaded from a file of the beforehand created matrix by pressing "…" button in Palette group. Set the diapasons of a palette of a created matrix of qualities can be executed after pressing the button ">> " in Palette group at the included mode Nonregular diapasons. A result file at building a matrix of qualities can be a file with ".mtq" extension or a file with ".mtw" extension. The choice of a file type is carried out by pressing "…" button, located to the right of "Matrix name" window.
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