How do you use Chart::ErrorBars?

[Ted Byers]

I found Chart::ErrorBars in the Chart documentation, and the following
is the only information I find about using it:

"'same_error' This is a option only for ErrorBars. It tells chart
that you want use the same error value of a data point if set to
'true'. Look at the documentation to see how the module ErrorBars
works. Default: 'false'."

This is from the documentation for Chart, so i don't know what this
other documentation is that this sentence refers to.

I took a quick look into the source code, but that has few comments,
and it isn't clear from that how to do what I need.

Creating an instance of a Chart::ErrorBars object seems simple:

use Chart::ErrorBars;
my $cobj = Chart::ErrorBars->new;

What isn't clear is how to tell it what the upper and lower bounds for
the error bars. For this task, what is important is to be able to
show that the upper and lower bounds of the 99% confidence interval of
the estimate are Yl and Yu, and the actual value is Ya (we really
don't care what the estimate of the expected value 'Ye' is, only
whether or not the actual value is within the confidence interval of
the expected value).

If I could even see a small example of how Chart::ErrorBars is used, I
could figure out the rest from there. I have succeeded using the line,
bar and pie charts from the Chart 'package', but this one has me
stumped (I MAY resort to a simple line chart, of I don't figure out
this Chart::ErrorBars object quickly).

Any help would be appreciated.

Thanks

Ted

 

[J. Gleixner]

Ted Byers wrote:
[...]

If I could even see a small example of how Chart::ErrorBars is used, I
could figure out the rest from there. [...]

Check the tests. e.g.

http://search.cpan.org/src/CHARTGRP/Chart-2.4.1/t/error_1.t