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--- gibson:teaching:spring-2016:math445:lecture:scripts [2016/02/01 07:39]
gibson
+++ gibson:teaching:spring-2016:math445:lecture:scripts [2016/02/03 13:54] (current)
gibson [Logarithmic plots]
@@ Line 1: / Line 1: @@
-====== Math 445 lecture 3: scripts ======
+====== Math 445 lecture 3: scripts and plotting ======
 topics
 <code>
   Matlab scripting
-  plot, semilogy, semilogx, loglog
+  linestyles and plot modifiers:
-  xlabel, ylabel, title, legend, axis, grid, clf,
+    xlabel, ylabel, title, legend, axis, grid, clf,
-  linestyles
   load, save
-  what, pwd
+  plot, semilogy, semilogx, loglog
+  what, who, pwd, ls
 </code>
@@ Line 40: / Line 40: @@
 MATLAB Code files in the current folder /home/gibson/math445
-plotsincos
+</code>
+When the script is run, Matlab opens a new figure window and draws the plot
+<code matlab>
 >> plotsincos % execute the plotsincos script
 </code>
-When the script is run, Matlab opens a new figure window and draws the plot
 {{ :gibson:teaching:spring-2016:math445:sincos.png?direct&400 |}}
+===== Line styles and markers =====
+The above plotting script used the matlab **linestyle** codes '' 'b-' '' and '' 'r-' '' to generate blue and red curves for $\cos x$ and $\sin x$. Matlab's **help** function provides a pretty good description of how line and marker style codes work.
+<code matlab>
+>> help plot
+   % clip out irrelevant stuff here
+   Various line types, plot symbols and colors may be obtained with
+    plot(X,Y,S) where S is a character string made from one element
+    from any or all the following 3 columns:
+           b     blue          .     point              -     solid
+           g     green         o     circle             :     dotted
+           r     red           x     x-mark             -.    dashdot
+           c     cyan          +     plus               --    dashed
+           m     magenta       *     star             (none)  no line
+           y     yellow        s     square
+           k     black         d     diamond
+           w     white         v     triangle (down)
+                               ^     triangle (up)
+                               <     triangle (left)
+                               >     triangle (right)
+                               p     pentagram
+                               h     hexagram
+    For example, plot(X,Y,'c+:') plots a cyan dotted line with a plus
+    at each data point; plot(X,Y,'bd') plots blue diamond at each data
+    point but does not draw any line.
+ </code>
+===== Plot modifiers =====
+Some helpful commands for modifying plots
+<code matlab>
+xlabel('foo') % add an x label
+ylabel('bar') % add a y label
+title('baz')  % add a title
+legend('first', 'second', 'third') % add a legend with these labels
+axis on       % turn on axes and ticks (default)
+axis off      % turn off axes and ticks
+axis square   % make the plot square
+axis equal    % scale the x and y axes the same
+axis([xmin xmax ymin ymax]) % force these specific bounds on the axes
+grid on       % turn on grid markers
+grid off      % turn off grid markers
+hold on       % hold the current plot; the next plot will be plotted on top of this one
+hold off      % release the current plot; the next plot will erase this one
+clf           % clear figure (erase current plot)
+figure(2)     % open new figure window, numbered 2
+</code>

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