About R chart

[chrisboo]

I have write a program which can capture the live image from the camera. Then, we use this program to calculate the contrast ratio and the contrast ratio will continuously generate in our program. Then, I want to use these data to plot a x bar chart and r chart. since the data( numerial data only) generate continuously, I am very difficult to plot r chart.
If you want more detail information, I can tell you.
Thanks

[LesHammer]

I would think all you would need to know is:
Minimum
Maximum
Average
NumberOfSamples

Then, on the next iteration:
If NewValue If NewValue>Maximum, set Maximum=NewValue
Average(new) = [Average(old)*NumberOfSamples+NewValue]/(NumberOfSamples+1)
Increment NumberOfSamples

r(new)=Maximum-Minimum

To decrease iteration errors, you could do this in batches of 1000 or 1000000. That is, every 1000 start a new average, then average all the averages.

Or am I missing something?

Les.Hammer@CompleteTest.com