I am looking for a charting control to be used in an MFC application that we want to convert to 64 bit. We have used ComponentOne Chart for years, but they do not have a 64-bit activeX version, and it looks like they aren't going to develop one.
* 64-bit activeX control
* line charts
* what excel would call scatter charts -- chart a line based on X and Y data where the X values are not evenly spaced.
* surface charts, where the input is Z values at X and Y coordinates, and the control charts a wire-mesh, or a smooth surface.
* contour charts, where again the input is Z values at X and Y coordinates, and the control charts contour lines, or contour color bands.
* can zoom in on the data, either through user interaction, or programatically.
* ability to handle large amounts of data. In the 3D surface charts, we would like to be able to handle at least 100x100 so 10,000 data points, and 500x500 (250,000 data points) would be nice.
I have searched and haven't found anything that meets our needs. Any suggestions?
I'm curious to know if having a small number of .mdb databases connections open at the same time will tax systems or if it's ok to do assuming they are only open for a brief instant in time.
For applications that briefly open an .mdb file while initializing, I normally try to pass a reference to an instance of CDatabase that has been opened on a database while loading data from tables. I'll usually close the database connection once I know I'm done. The database remains open for less than a second.
I'm now faced with the need to read from multiple .mdb files while initializing, with no guaranteed order, and the potential to need to alternate reads between the databases. I've noticed that there is a big time difference if I close the old database connection and open a new one when I need to switch which database I'm reading from.
My intention is to keep a small array of those open database connections to keep the duration of the loading time to a minimum and close them promptly once I'm done.
Are there any hidden "gotchas" to doing this? Is it unwise to keep more than one instance of a database open at a time?
Well, after benchmarking many combinations using multiple .mdb files, this does not affect performance or memory usage in any significant way.
(For anyone who might stumble upon my question and wonder how this ended up)
You can have one method to read the "raw" data for each data line as long as they follow the same pattern, for example, in your case, it looks like:
<name> <data1> <data2> <data3>
after that, you have to interpret each data like depending on where it comes from, is it from Dow ? is it from "Oil"? and decide if it's a percentage, a absolute value, a "delta" and put those values in the appropriate fields in your application :