im working on a real time graph with four y-axes, two on either side of the plot window. All four can be individually set to auto or manual scale. I set the transform to CartesianCoordinates and used SetAxisIntercept for positioning the far left and right y-axes. The scroll frames and polt lines are using a seperate TimeCoordinates transform. This all works well for manual scale. In auto the plot lines scale correctly but the y-axes do not. I use the ChartObj.RT_AUTOSCALE_Y_MINMAX for the RTScrollFrame. I assume tihs happens because the y-axes are on different transforms then the scroll frame. If I put these axes on a TimeCoordinates transform along with the scroll frame, SetAxisIntercept does not work. When I put the scroll frame and axes on different TimeCoordinates transforms and adjust the SetGraphBorderDiagonal for positioning the axes the plot lines shift over along with the axes.
A RTScrollFrame can only manage one coordinate system. Every coordinate system (you have 4 since you have four different y-axes) must use a separate RTScrollFrame. It is not clear if that is what you are doing. See the example RTStockDisplay for an example which uses two RTScrollFrames for two overlaid coordinate systems, with a y-axis on the left and right, and with RT_AUTOSCALE_Y_MINMAX set for both.
Every overlaid coordinate system must use the same positioning rectangle - SetGraphBorderDiagonal. Once you have that setup don't change it.
There are four seperate scroll frames and four seperate transforms. All of the transforms have the same positioning rectangle coordinates. two of the y-axes are positioned using xaxis.AxisMax and xaxis.AxisMin. The problem im running into is positioning the other two next to the first two. when I use SetAxisIntercept the axis Disappears. I used the same SetAxisIntercept coordinate with a CartesianCoordinates transform and the axes where right where I wanted them. What is the best way to position y-axes on a TimeCoordinates transform that wont be on xaxis.AxisMax or xaxis.AxisMin.
Multiple auto scaling y-axes
Posted - 25 Aug 2011 : 09:07:08
