$fracture rose diagram$

$fracture rose diagram$

Include 'Dominant Angle' Text (Deg) - This option plots the lineaments' dominant angle above each rose diagram. Include Grid Cell Lines - This option plots the regional grid outlines on the Map Module. Rose 'Petal' Width (1 to 90 Degrees) - This option sets the the angle increment used when building orientation histograms. It's best to set this values no larger than the grid cell size.

$fracture rose diagram$

Maximum Diameter (XY Map Units) - This option sets the size of the largest rose diagram.

$fracture rose diagram$

Line Color - This option sets the overlay color for the rose diagrams' outline.įill Color - This option sets the overlay color for the rose diagrams' interior fill. The Rose tab sets a few additional details on how the rose diagram plots. This layer can not be in a read-only mode. Petra will completely replace the contents of this layer before storing new data. Store Results In Layer - This dropdown contains the layer name of the layer receiving the rose diagrams, text and other graphics. Layers tabĪnalyze Lines From Layer - This dropdown sets the overlay layer containing all lines, fractures, lineaments, etc. There are two button to set the grid extents to the current screen limits or the limits defined by the well data on the map. The appropriate x and y increment will be computed. If you wish to have the region divided into a 10 rows by 10 columns, simply enter 10 in the 'NxN' field and click the 'Set' button. The cell size of increment also defined in XY map units. The regional grid is defined as a rectangular box in XY map units. The dominant angle is the 'mode' of the histogram, i.e., the orientation that has the longest line segments. The dominant angle of orientation for each regional grid cell can be posted above the rose diagram. The 'length value' for a cell is the percent of the cell's length to the maximum length. Then, the maximum of these lengths is found. The total length of all lines inside a regional cell are totaled. Values can be posted that provide a relative length of lines in a regional grid cell. If a line crosses a subgrid cell, then the area of the subcell, or 1% of the regional grid cell, is summed as 'area coverage' value and can be posted. This sub-grid is used to determine the percent of area coverage by lineaments of fractures. Only the portion of a line lying within a cell is considered in these calculations.Įach regional grid cells is, in turn, subdivided into a series of 10x10 grid cells. The total length of lines within each cell is summed and a histogram is built based on the orientation of each line segment. The outlines of the grids can be seen in Figure 1. Lineament or fracture data in an overlay layer is subdivided into a series of regional grid cells. This feature analyzes line data from an overlay layer and generates rose diagrams illustrating orientation and coverage of the lineament features on a regional basis.

$fracture rose diagram$

Fracture rose diagram