Can You Create Trend Line in CFCHART?

Question

Have pretty much got CF7 Charts and WebCharts3D down, at
least to the point where they can do what I need the most. However,
the one thing I'd like to be able to do, but not sure if it's
possible, is create a TREND LINE.
This would be a LINE charts with 2 series. The first series
would be a line with the actual counts covering a period of time.
I'd like to add a 2nd line, using the same data from the
first series, but have it displayed as a TREND line. In Excel, you
can easily create a TREND line, it's even offered as an option.
I've seen somehwere (CFCHART or WebCharts3D) something to so
with "logarithmic" options, which is one of the options for Excel
charts.
Two more quick questions:
Q1. Is there any way to control the margin between the left
and right borders of the charts, and the bars? Have tried
experimenting, but can't seem to get this to work. Reason is, when
I try to show a chart in 3D, the first bar on the left is "butted
up" against the left chart border. Would like to add a little space
there.
Q2. Rather than display rectangular bars, I'd like to display
rounded cylinders. I've tried setting the chart type in CFCHART to
"cylinder" but it still displays a bar. When I try to change the
type to "cylinder" in WebCharts3D, the chart STILL displays
rectangular bars. Yet I've seen many examples of rounded, cylinder
bars.
Don't mean to push my luck with too many questions. Thanks
for any advice, help.
Gary

Answer 1

Trend Lines:
CFChart does not do trend lines of any type. However, it is
not too difficult to compute the regression of your choice and to
plot it as a second series.
Logarithmic:
Not sure what you are asking here.
In theory, cfchart does do log-lin and log-log charts.
However, it is so buggy, and the scaling problems are so
great, that we have never been able to get it to work well.
We use ChartDirector for anything that requires a log scale.
Side margins:
You cannot control these directly. Here are some workarounds:
For "Category" axis:
Make sure the "isBucketed" property is set to true (this is the
default).
If that is not enough, add extra bars to your data series,
usually value zero. It's not ideal but it may be good enough.
For "Scale" axis:
Usually this works well enough. Otherwise, try toggling the
"isAbsolute" property.
The only other recourse is to manually scale the plot using the
"scaleMin" and "scaleMax" properties. This can be a real pain for
obvious reasons and also because cfchart scaling is fraught with
bugs and "quirks".
Cylinder Bars:
These work. Perhaps there was a setting conflict within the
XML or between the CFChartSeries setting and the XML?
Also the cylinders will only look round when 3D is turned on.
(Side view of a cylinder is just a shaded bar.)
Anyway, I've said it before: cfchart is barely usable for a
very limited range of charts.
For real business or common engineering and scientific needs,
you need to step up to something better.
The package we use (has all the features and very reasonably
priced) is ChartDirector (
http://www.advsofteng.com/cdcoldfusion.html).
(And, no, I'm not affiliated.)