@ClusteredMining问制作热图 - 如何定义渐变中每种颜色的值？. 这并不能完全回答问题，但也许。 使用 GradientFunction 和颜色列表，可以用第三种颜色获得非常清晰的边界。 通过定制一长串颜色来产生清晰的边界，许多变化是可能的。 或模糊，这可能看起来更漂亮。
GradientFunction 需要一些 JSL 来回答这个问题“这里的 Z 值是多少？ “ 该功能可能不容易使用，因为数据在表中，并且没有很好地网格化。
编辑：您应该使 totalWidth 变大而不是变小；它控制 colorList 中的颜色数量，后者控制边缘放置的精度。 您可能也应该使网格值大一点。 grid=100 和 totalWidth=100 似乎比 50 和 10 更合理。
// these are in units of the Z value
range = {100, 400}; // the range of the color list; the formula a*b on the axis 10..20 makes these numbers
targetValue = 200; // happens to go through the corners for this example.
// grid: this determines how many points are evaluated by GradientFunction
grid = 50; // subdivisions, more looks smoother, is slower. typically 50 to 500. 667 may be a limit.
// how many colors in the colorList
thick = 0.050; // thickness of division line, can be 0. 50% is really fat (0.5)
totalWidth = 10; // make this smaller for a blurred edge, maybe 10 or 100 instead of 1000, which has a sharper edge
targetWidth = Round( thick * totalWidth );// making the green target about 10%, so kind of thick
otherwidth = totalWidth - targetWidth; // the ratios, below, divides this in parts
lowRatio = (targetValue - range[1]) / (range[2] - range[1]);// the red
highRatio = 1 - lowRatio;// the blue
// this list is a bunch of repeated reds, a few greens, and a
// bunch of blues. The greens are centered at the targetValue.
colorList = {};
Insert Into( colorList, As List( Repeat( RGB Color( .4, 0, 0 ), Round( otherwidth * lowRatio ) ) ) );
Insert Into( colorList, As List( Repeat( RGB Color( 0, .6, 0 ), targetWidth ) ) );
Insert Into( colorList, As List( Repeat( RGB Color( 0, 0, .4 ), Round( otherwidth * highRatio ) ) ) );
New Window( "target=" || Char( targetValue ),
g = Graph Box(
X Scale( 10, 20 ),
Y Scale( 10, 20 ),
framesize( 600, 400 ),
Gradient Function(
a * b,
a,
b,
Matrix( range ), // range to map the colors onto
Z Color( colorList ),
<<XGRID></XGRID>
尝试使用 grid、width 和 totalThick 来获得有趣的图表：
A thin sharply defined green region between red and blue.A thin sharply defined green region between red and blue.A thin sharply defined green region between red and blue.A thin sharply defined green region between red and blue.A thin sharply defined green region between red and blue.红色和蓝色之间的薄而清晰的绿色区域。
Thicker, and still sharp.Thicker, and still sharp.Thicker, and still sharp.Thicker, and still sharp.Thicker, and still sharp.更厚，仍然锋利。
Thicker, and blurry.Thicker, and blurry.Thicker, and blurry.Thicker, and blurry.Thicker, and blurry.更厚，更模糊。
