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Wed Dec 11 19:04:47 2002 UTC (21 years, 7 months ago) by albertel
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CVS tags: version_2_9_X, version_2_9_99_0, version_2_9_1, version_2_9_0, version_2_8_X, version_2_8_99_1, version_2_8_99_0, version_2_8_2, version_2_8_1, version_2_8_0, version_2_7_X, version_2_7_99_1, version_2_7_99_0, version_2_7_1, version_2_7_0, version_2_6_X, version_2_6_99_1, version_2_6_99_0, version_2_6_3, version_2_6_2, version_2_6_1, version_2_6_0, version_2_5_X, version_2_5_99_1, version_2_5_99_0, version_2_5_2, version_2_5_1, version_2_5_0, version_2_4_X, version_2_4_99_0, version_2_4_2, version_2_4_1, version_2_4_0, version_2_3_X, version_2_3_99_0, version_2_3_2, version_2_3_1, version_2_3_0, version_2_2_X, version_2_2_99_1, version_2_2_99_0, version_2_2_2, version_2_2_1, version_2_2_0, version_2_1_X, version_2_1_99_3, version_2_1_99_2, version_2_1_99_1, version_2_1_99_0, version_2_1_3, version_2_1_2, version_2_1_1, version_2_1_0, version_2_12_X, version_2_11_X, version_2_11_5, version_2_11_4_uiuc, version_2_11_4_msu, version_2_11_4, version_2_11_3_uiuc, version_2_11_3_msu, version_2_11_3, version_2_11_2_uiuc, version_2_11_2_msu, version_2_11_2_educog, version_2_11_2, version_2_11_1, version_2_11_0_RC3, version_2_11_0_RC2, version_2_11_0_RC1, version_2_11_0, version_2_10_X, version_2_10_1, version_2_10_0_RC2, version_2_10_0_RC1, version_2_10_0, version_2_0_X, version_2_0_99_1, version_2_0_2, version_2_0_1, version_2_0_0, version_1_99_3, version_1_99_2, version_1_99_1_tmcc, version_1_99_1, version_1_99_0_tmcc, version_1_99_0, version_1_3_X, version_1_3_3, version_1_3_2, version_1_3_1, version_1_3_0, version_1_2_X, version_1_2_99_1, version_1_2_99_0, version_1_2_1, version_1_2_0, version_1_1_X, version_1_1_99_5, version_1_1_99_4, version_1_1_99_3, version_1_1_99_2, version_1_1_99_1, version_1_1_99_0, version_1_1_3, version_1_1_2, version_1_1_1, version_1_1_0, version_1_0_99_3, version_1_0_99_2, version_1_0_99_1, version_1_0_99, version_1_0_3, version_1_0_2, version_1_0_1, version_1_0_0, version_0_99_5, version_0_99_4, version_0_99_3, version_0_99_2, version_0_99_1, version_0_99_0, version_0_6_2, version_0_6, loncapaMITrelate_1, language_hyphenation_merge, language_hyphenation, conference_2003, bz6209-base, bz6209, bz5969, bz2851, PRINT_INCOMPLETE_base, PRINT_INCOMPLETE, HEAD, GCI_3, GCI_2, GCI_1, BZ5971-printing-apage, BZ5434-fox, BZ4492-merge, BZ4492-feature_horizontal_radioresponse
- spellchecked (BUG#1052)

    1: \label{Authoring_Piecewise_Plot}
    2: Suppose you want to plot a piecewise function similar to the
    3: following:
    4: 
    5: \begin{verbatim}
    6: f(x) = a*x + b if (x < 4.5)
    7: f(x) = a*x     if (x >=4.5)
    8: \end{verbatim}
    9: 
   10: The following is the XML representation of a problem with a dynamic
   11: plot based on this. The work is done in a <script> block that
   12: generates the data sets used in the plot.
   13: 
   14: \begin{verbatim}
   15:  <script type="loncapa/perl" >
   16:  $a = &random(2,5,1);
   17:  $b = &random(3,6,1);
   18:  
   19:  for ($x = 0; $x<4.5; $x+= 0.05) {
   20:      push @X, $x;
   21:      push @Y, $a*$x + $b;
   22:  }
   23:  
   24:  for ($x = 4.5; $x<=10; $x+= 0.05) {
   25:      push @X, $x;
   26:      push @Y, $a*$x;
   27:  }
   28:  </script >
   29:  <gnuplot font="medium" width="500" grid="on" height="400" border="on" 
   30:           fgcolor="x000000" alttag="dynamically generated plot" align="center" 
   31:           bgcolor="xffffff" transparent="off" >
   32:      <curve linestyle="lines" pointsize="1" pointtype="1" color="x000000" 
   33:       name="">
   34:          <data >@X</data >
   35:          <data >@Y</data >
   36:      </curve >
   37:  </gnuplot >
   38: \end{verbatim}
   39: 
   40: The above script works, but it produces a plot like this:
   41: 
   42: \includegraphics{dynamic_piecewise}
   43: 
   44: A better solution is to use two separate <curve> statements to plot
   45: two separate curves. So on the second piece of the function we use
   46: @X2 and @Y2 instead of @X and @Y. Then in the <gnuplot> tag we
   47: include a second <curve> sub-tag.
   48: 
   49: \begin{verbatim}
   50:  <script type="loncapa/perl" >
   51:  $a = &random(2,5,1);
   52:  $b = &random(3,6,1);
   53:  
   54:  for ($x = 0; $x<4.5; $x+= 0.05) {
   55:      push @X, $x;
   56:      push @Y, $a*$x + $b;
   57:  }
   58:  
   59:  for ($x = 4.5; $x<=10; $x+= 0.05) {
   60:      push @X2, $x;
   61:      push @Y2, $a*$x;
   62:  }
   63:  </script >
   64:  <gnuplot font="medium" width="500" grid="on" height="400" border="on" 
   65:           fgcolor="x000000" alttag="dynamically generated plot" align="center" 
   66:           bgcolor="xffffff" transparent="off" >
   67:      <curve linestyle="lines" pointsize="1" pointtype="1" color="x000000" 
   68:       name="" >
   69:          <data >@X</data >
   70:          <data >@Y</data >
   71:      </curve >
   72:      <curve linestyle="lines" pointsize="1" pointtype="1" color="x000000" 
   73:       name="" >
   74:          <data >@X2</data >
   75:          <data >@Y2</data >
   76:      </curve >
   77:  </gnuplot >
   78: \end{verbatim}
   79: 
   80: \includegraphics{dynamic_piecewise2}
   81: 
   82: This is still not a desirable result. Typically one wants an open
   83: circle or closed circle defining the domain of each
   84: piece. Unfortunately there is no easy way to do this in gnuplot
   85: currently. If this effect is desired, perhaps using a static image
   86: and a randomlabel problem would be a better approach. A second
   87: solution would be to add data which draws a circle to your curves.
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