MATLAB Examples

# Writing the geometry definition (from Matlab) with a grid of scattered points

This is an example where a grid of scattered points is to be written with a geometry. The geometry used comes from the example #1 of EABE_v34_p30. This set of points is used for the demo on interpolation with a scattered set of points.

## Creation of the grid where the function is known

```% Definition of the geometry obj = obj_AFP_V1_00; obj.file_geom_definition = 'R_fcts_geom\Files_geom_definition\EABE_v34_p30_ex1'; % Shape of the geometry % Analysis of the geometry obj = Analyse_geometry_definition(obj); % Generation of a random set of points on the rectangular domain ([0 11],[0 7]) Nb_pts_by_unit_length_each_dimension = 4; Nb_pts_x = 11*Nb_pts_by_unit_length_each_dimension; Nb_pts_y = 7*Nb_pts_by_unit_length_each_dimension; Nb_pts_rectangular_domain = Nb_pts_x*Nb_pts_y; Pts_rand_x = 11*rand(Nb_pts_rectangular_domain,1); % To cover the length [0 11] Pts_rand_y = 7*rand(Nb_pts_rectangular_domain,1); % To cover the length [0 7] Pts_z = zeros(Nb_pts_rectangular_domain,1); % Even when working in 2D, the "z" coordinate should be given for points % distributions. Pts_coord_to_determine = [Pts_rand_x Pts_rand_y Pts_z]; % These are the points on the whole rectangular domain. Some of these % points are outside the limits of the geometry. % Determination of the points inside the geometry L_pts_inside = Determine_pts_inside(obj,Pts_coord_to_determine); Pts_coord_to_keep = Pts_coord_to_determine(L_pts_inside,:); ```

## Display

```h = plot(obj); % Plot of the geometry hold on plot(Pts_rand_x,Pts_rand_y,'b.'); % Distribution on the rectangular area (blue points) h_pts_kept = plot(Pts_coord_to_keep(:,1),Pts_coord_to_keep(:,2),'ro'); % Distribution of the kept points (those inside the % geometry are encircled in red) set(h_pts_kept,'MarkerSize',5) title('Geometry and scattered grid') xlabel('x') ylabel('y') ```

## Writing the geometry information with the grid

```obj = calc_pts_distr(obj,'replace',Pts_coord_to_keep); % The grid to write in the file is the one in |Pts_coord| (filled by % the use of |calc_pts_distr|). WriteCADMatlab(obj,[pwd,'\R_fcts_geom\Files_geom_definition\EABE_v34_p30_ex1_w_scattered_grid.m']) ```