|
 discrete heatmap axis labels not showing negative sign |
| Posted by David on Jun-22-2022 19:10 |
|
Hello,
There seems an issue with axis labels in discrete heatmap in ChartDirector 7:
As an example, modifying the labels of the discreteheatmap example in mfcdemo:
void discreteheatmap(CChartViewer *viewer, int /* chartIndex */)
{
// The x-axis and y-axis labels
const char* xLabels[] = {"-10", "-5", "-0.0001", "0.0001", "E", "F", "G", "H", "I", "J"};
const int xLabels_size = (int)(sizeof(xLabels)/sizeof(*xLabels));
const char* yLabels[] = {"-10", "1000", "2", "3", "4", "5", "6", "7", "8", "9"};
const int yLabels_size = (int)(sizeof(yLabels)/sizeof(*yLabels));
....
The negative signs were not shown in the chart. |
| Re: discrete heatmap axis labels not showing negative sign |
| Posted by Peter Kwan on Jun-22-2022 22:36 |
|
Hi David,
Strange as it seems, it is by design.
Due to a decision we made a long long time ago when we first supported minor ticks, we chose to use the "-" character to mean that the label is associated with a minor tick. In the discrete heat map examples, they hide the ticks. But in charts that show the ticks, you can see the ticks associated with the "-" labels are shorter.
We now think using "-" for minor ticks is not a good idea, but due to our commitment to backwards compatibility, we have not changed this behaviour. See:
https://www.advsofteng.com/doc/cdcpp.htm#Axis.setLabels.htm
To add the "-0.0001", we need to escape it to "-0.0001". Now "" has a special meaning in C++ literal string, and we need to escape it too. So in C++, it becomes "\\-0.0001".
Regards
Peter Kwan |
| Re: discrete heatmap axis labels not showing negative sign |
| Posted by Peter Kwan on Jun-22-2022 22:38 |
|
Hi David,
For the last paragraph, I mean:
To add the "-0.0001", we need to escape it to "\\-0.0001". Now "" has a special meaning in C++ literal string, and we need to escape it too. So in C++, it becomes "\\\\-0.0001".
(The forum itself will escape the \\ character. So I need to type 4 backslashes in order to display 2 backslashes in the forum.)
Regards
Peter Kwan |
| Re: discrete heatmap axis labels not showing negative sign |
| Posted by David on Jun-22-2022 22:48 |
|
| Cool. I'll get it a try. Thanks! |
|
Forum Home
Search
Message List
Post Message