Changes

170 bytes removed ,  23:26, 23 April 2017
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→‎Demos and usage examples: proofread a new example: fix typos and style
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<source lang="octave">
 
<source lang="octave">
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##The following code will produce the same vector field plot as Figure 1.14 from Example 1.6 (pg. 39) from A Student's Guide to Maxwell's Equations by Dr. Daniel Fleisch.
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## The following code will produce the same vector field plot as Figure 1.14 from Example 1.6 (pg. 39) from A Student's Guide to Maxwell's Equations by Dr. Daniel Fleisch.
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##Make sure symbolic package is loaded and symbolic variables declared.
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## Make sure symbolic package is loaded and symbolic variables declared.
pkg load symbolic;
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pkg load symbolic
 
syms x y
 
syms x y
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##Write a Vector Field Equation in terms of symbolic variables  
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## Write a Vector Field Equation in terms of symbolic variables  
vector = [sin(pi .* y ./2 ); -sin(pi .* x ./2 )];
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vectorfield = [sin(pi*y/2); -sin(pi*x/2)];
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##Vector components are converted from symoblic into anonymous form which allows them to be graphed
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## Vector components are converted from symbolic into "anonymous functions" which allows them to be graphed.
##The '1' & '2', in vector(1) & vector(2) are indeces for the vector.
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## The "'vars', [x y]" syntax ensures each component is a function of both 'x' & 'y'
##The " 'vars', [x y]" syntax tells function_handle that each component is a function of both 'x' & 'y'
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iComponent = function_handle (vectorfield(1), 'vars', [x y]);  
iComponent = function_handle (vector(1), 'vars', [x y]);  
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jComponent = function_handle (vectorfield(2), 'vars', [x y]);  
jComponent = function_handle (vector(2), 'vars', [x y]);  
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##Setting the Grid up to graph all axes for all variables from -.5 to .5, with spacings .05 apart.
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## Setup a 2D grid
[X,Y] = meshgrid([-.5:.05:.5]);
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[X,Y] = meshgrid ([-0.5:0.05:0.5]);
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##Draw the Vector Field!
   
figure
 
figure
quiver(X,Y,iComponent(X,Y),jComponent(X,Y))
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quiver (X, Y, iComponent (X, Y), jComponent (X,Y))
    
</source>
 
</source>
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