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<H3><A NAME="8_2_9">8.2.9 Using gradient fill for bar graphs</A></H3>
<P> It is possible to use color gradient fill for the individual bars in
 the bar graph.</P>
<P> Color gradient fill fills a rectangle with a smooth transition
 between two colors. In what direction the transition goes (from left to
 right, down and up, from the middle and out etc) is determined by the
 style of the gradient fill. JpGraph currently supports 8 different
 styles. All supported styles are displayed in the figure below.<DIV class="example">
<BR> <A href="exframes/frame_bargradsmallex1.html" target="blank"><IMG border="0"
HEIGHT="150"  src="img/bargradsmallex1.png" WIDTH="200"></A>
<BR><B>Figure 44:</B> <A href="exframes/frame_bargradsmallex1.html" target="blank">
[src]</A>&nbsp;
<P></P>
</DIV></P>
<P><DIV class="example">
<BR> <A href="exframes/frame_bargradsmallex2.html" target="blank"><IMG border="0"
HEIGHT="150"  src="img/bargradsmallex2.png" WIDTH="200"></A>
<BR><B>Figure 45:</B> <A href="exframes/frame_bargradsmallex2.html" target="blank">
[src]</A>&nbsp;
<P></P>
</DIV></P>
<P><DIV class="example">
<BR> <A href="exframes/frame_bargradsmallex3.html" target="blank"><IMG border="0"
HEIGHT="150"  src="img/bargradsmallex3.png" WIDTH="200"></A>
<BR><B>Figure 46:</B> <A href="exframes/frame_bargradsmallex3.html" target="blank">
[src]</A>&nbsp;
<P></P>
</DIV></P>
<P><DIV class="example">
<BR> <A href="exframes/frame_bargradsmallex4.html" target="blank"><IMG border="0"
HEIGHT="150"  src="img/bargradsmallex4.png" WIDTH="200"></A>
<BR><B>Figure 47:</B> <A href="exframes/frame_bargradsmallex4.html" target="blank">
[src]</A>&nbsp;
<P></P>
</DIV></P>
<P><DIV class="example">
<BR> <A href="exframes/frame_bargradsmallex5.html" target="blank"><IMG border="0"
HEIGHT="150"  src="img/bargradsmallex5.png" WIDTH="200"></A>
<BR><B>Figure 48:</B> <A href="exframes/frame_bargradsmallex5.html" target="blank">
[src]</A>&nbsp;
<P></P>
</DIV></P>
<P><DIV class="example">
<BR> <A href="exframes/frame_bargradsmallex6.html" target="blank"><IMG border="0"
HEIGHT="150"  src="img/bargradsmallex6.png" WIDTH="200"></A>
<BR><B>Figure 49:</B> <A href="exframes/frame_bargradsmallex6.html" target="blank">
[src]</A>&nbsp;
<P></P>
</DIV></P>
<P><DIV class="example">
<BR> <A href="exframes/frame_bargradsmallex7.html" target="blank"><IMG border="0"
HEIGHT="150"  src="img/bargradsmallex7.png" WIDTH="200"></A>
<BR><B>Figure 50:</B> <A href="exframes/frame_bargradsmallex7.html" target="blank">
[src]</A>&nbsp;
<P></P>
</DIV></P>
<P><DIV class="example">
<BR> <A href="exframes/frame_bargradsmallex8.html" target="blank"><IMG border="0"
HEIGHT="150"  src="img/bargradsmallex8.png" WIDTH="200"></A>
<BR><B>Figure 51:</B> <A href="exframes/frame_bargradsmallex8.html" target="blank">
[src]</A>&nbsp;
<P></P>
</DIV></P>
<P></P>
<P> To specify a gradient fill for the bar plots you make use of the
 method <A href="../ref/BarPlot.html#_BARPLOT_SETFILLGRADIENT">
 BarPlot::SetFillGradient()</A> . See the class reference for details of
 this function.</P>
<P> When using gradient fills there are a couple of caveats you should
 be aware of:</P>
<UL>
<LI>gradient filling is computational expensive. Large plots with
 gradient fill will take in the order of 6 times longer to fill then for
 a normal one-color fill. This might to some extent be helped by making
 use of the cache feature of JpGraph so that the graph is only generated
 a few times.</LI>
<LI>gradient filling will make use of much more colors (by definition)
 this will make the color palette for the image bigger and hence make
 the overall image larger. It might also have some severe effect on
 using anti-aliased line in the same image as color gradient filling
 since anti-aliased lines also have the possibility to make use of many
 colors. Hence the color palette might not be big enough for all the
 colors you need. So if you use gradient fills you should also be using
 a true-color image since you otherwise run out of colors.
<BR> This problem is often seen as that for no apparent reason some
 color you have specified in the image does appear as another color.
 (This is not a bug in JpGraph!) This is something to especially watch
 out for when enabling anti-aliasing since that also uses a lot of
 colors. Since the numbers of colors used with anti-aliasing depends on
 the angle on the lines it is impossible to foresee the number of colors
 used for this.</LI>
</UL>
<P></P>
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