核心情节iOS逆转Y轴 [英] core-plot iOS reversed Y axis

问题描述

我想使用核心图来显示水深图（实时更新）但我无法弄清楚如何反转Y轴，以便X轴（代表时域）打开我的UIView的顶部和Y轴以正值向下增长。

I would like to use core-plot to display a water depth graph (updated in real time) but I can't figure out how to reverse the Y axis, so that the X axis (representing the time domain) is on the top of my UIView and the Y axis grows towards the bottom with positive values.

编辑

如果我能画这样的轴会更好：

- X轴是时间

- Y轴从0到X（X> 0）并且在顶部有0，在底部有X

- X轴在底部

It would be even better if I could draw axes like this:
- X axis is time
- Y axis is from 0 to X (X > 0) and on the top there is 0, on the bottom there is X
- X axis is on the bottom

ASCII版本：

0 |

1 |

。

。

。< br>
x |

--------------------------

0 1 2 3 4 5 6 7 ...

0 |
1 |
.
.
.
x |
--------------------------
0 1 2 3 4 5 6 7 ...

推荐答案

您可以使用负长度绘制范围来反转轴的方向。例如（来自CPTTestApp中的轴演示）：

You can use a negative length for the plot range to reverse the direction of an axis. For example (from the axis demo in CPTTestApp):

plotSpace.xRange = [CPTPlotRange plotRangeWithLocation:CPTDecimalFromDouble(0.0)
                                                length:CPTDecimalFromDouble(-10.0)];

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