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  Engauge Digitizer - Digitizing Point Graphs</H2>
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Warning: Not all point graphs work well when automatically matching points
in Engauge. Before going any further, you may want to read about 
<A HREF="pointmatchrequirements.html">point match requirements</A>.
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<H3>Typical Set of Steps To Digitize Point Graphs</H3>
<P>The following steps digitize a linear cartesian graph with 
points along one curve:</P>
<UL>
<LI>Obtain an image file (bitmap, jpeg or other) showing one or more 
graphs and both axes</LI>
<LI>Import the image file using one of the following options:
  <UL>
  <LI>File/Import menu option</LI>
  <LI>Copying and pasting</LI>
  <LI>Dragging and dropping</LI>
  </UL>
</LI>
<LI>Click on the Axes Point button before entering axes points. These 
will define the coordinate system</LI>
<LI>Click on one of the axes to add the first axes point, then enter 
its graph coordinates</LI>
<LI>Click on one of the axes to add the second axes point, then enter 
its graph coordinates</LI>
<LI>Click on one of the axes to add the third axes point, then enter 
its graph coordinates</LI>
<LI>Click on the <A HREF="tutorautopointgraph.html">Point Match</A> button
to automatically digitize many
curve points.</LI>
<LI>Click on a sample point, and then use the arrow keys to accept
or reject points that match the sample point.</LI>
<LI>Click on the Curve Points button to manually enter curve points.</LI>
<LI>Click on the curve to add a curve point</LI>
<LI>Repeat the previous step until the curve is covered with a 
sufficient number of curve points</LI>
<LI>Export curve points using one of the following options:
  <UL>
  <LI>File/Export menu option to save <A HREF="dlgexport.html">selected 
  curves</A> into a tabular text file</LI>
  <LI>Copying and pasting to copy points in the current curve from the 
  <A HREF="dlgcurvegeometry.html">curve geometry window</A> to another application</LI>
  <LI>Dragging and dropping to copy points in the current curve from the 
  <A HREF="dlgcurvegeometry.html">curve geometry window</A> to another application</LI>
  </UL>
</LI>
</UL>
<H3>Optional Steps</H3>
<P>To clean up the image for better performance of
Segment Fill and Point Match:
steps:</P>
<UL>
<LI>Show the processed image, rather than the original image, by
selecting the View/Background/Show Filtered Image menu option</LI>
<LI>Adjust the discretize settings using the Settings/Discretize
menu option, until unwanted parts of the image disappear</LI>
<LI>Remove grid lines using the Settings/Grid Removal
menu option</LI>
</UL>
<P>For a graph that is logarithmic or polar:</P>
<UL>
<LI>Select the Settings/Coords menu option to bring up the 
<A HREF="dlgcoordsys.html">coordinates window</A></LI>
<LI>Select the appropriate coordinate settings</LI>
</UL>
<P>For a graph with more than one curve:</P>
<UL>
<LI>Select the Settings/Curves menu option to bring up the 
<A HREF="dlgcurves.html">curves window</A></LI>
<LI>Click on the New button to create a new curve, then enter the 
name of the new curve</LI>
<LI>Repeat the previous step until all desired curve names have 
been entered</LI>
<LI>In the main window, use the Curves combobox to select a curve. 
While that curve is selected, all new curve points will be assigned 
to that curve</LI>
</UL>
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