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<A HREF = "index.html">[Index for ./FEM]</A> |
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<H1>sample_field_2d</H1> |
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<H2>(./FEM/sample_field_2d.m)</H2> |
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<HR><H3>Function Synopsis</H3> |
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<pre>outmat=sample_field_2d(fem_grid_struct,nx,ny,Q,box_coords)</pre> |
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<HR><H3>Help text</H3> |
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<pre> |
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SAMPLE_FIELD_2D Mouse-driven 2-D FEM Field Sampler |
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SAMPLE_FIELD_2D is a mouse-driven 2-D field sampler prompts |
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the user to draw a box on the current figure, and |
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returns an array of coordinates and interpolated |
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field values. The input field array can be any number |
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of columns wide (scalar, vector, etc.) but must be as |
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long as the node coordinate lists in <A HREF = "../3.FEM/fem_grid_struct.html">fem_grid_struct</A>. |
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I.e., the fields to interpolate will usually come from |
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the FEM domain itself. |
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INPUT: <A HREF = "../3.FEM/fem_grid_struct.html">fem_grid_struct</A> - FEM domain structure on which the field |
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to sample is related (from <A HREF = "../3.FEM/loadgrid.html">LOADGRID</A>, see <A HREF = "../3.FEM/fem_grid_struct.html">FEM_GRID_STRUCT</A>). |
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nx,ny - number of points in the x and y direction at which to |
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sample the fields Q. (REQUIRED, INTEGERS) |
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Q - the fields to sample. This array must be the same length as |
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the node coordinate arrays in the valid <A HREF = "../3.FEM/fem_grid_struct.html">fem_grid_struct</A> |
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passed in, but the number of columns is arbitrary. |
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box_coords - optional 4x1 vector defining the sample region. |
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The 4 values are [X1 Y1 X2 Y2], and if defined |
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they take precedence over the mouse-driven facility. |
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OUTPUT: S - an array containing the sample points and sample values. |
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If nx or ny==1, then S contains the sample points and |
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sample values in columns. Otherwise, S is an |
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[nx X ny X ncol] array, where ncol is the number of |
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columns in the input array Q and the first 2 levels of |
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S are the X and Y coordinates (X=S(:,:,1), Y=S(:,:,2)). |
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Points not located within FEM domain are assigned NaN's |
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as field values. |
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|
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To contour the results in the case where nx and ny > 1, |
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call MATLAB's contourf routine with S appropriately |
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sampled. For example: |
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>> contourf(S(:,:,1),S(:,:,2),S(:,:,3)) |
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CALL: S=sample_field_2d(<A HREF = "../3.FEM/fem_grid_struct.html">fem_grid_struct</A>,nx,ny,Q) |
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|
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Written by Brian O. Blanton |
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Summer 1998 |
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|
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</pre> |
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<HR><H3>Cross-Reference Information</H3>This function calls |
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<pre><UL> |
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<LI><A HREF = "../3.FEM/is_valid_struct.html">is_valid_struct</A>./FEM/is_valid_struct.m</LI> |
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</UL></pre> |
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<HR> |
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