Iam reading temperature data into a circular buffer. I would like to take that data and reverse it

[bwc1]

Iam reading temperature data into a circular buffer. I would like to take that data and reverse it so that i can feed it into a statistical module to find were the variance becomes lower than 5. Any ideas ?

[CJ_Butler__DASYLab_Pro]

My first reaction is that you can't do that with DASYLab.... data is processed in a forward direction.

When I teach DASYLab, I point out that there are simply some analysis functions that cannot be done with this data model -- and refer customers to post processing programs such as Diadem or Excel, where you have better data set manipulation. 

Generally speaking, if you need the whole data set to compute something that cannot be compute with running, online data, then you are best off with post-processing.

Having said all that.... can you restate the problem with an example of the data and why you cannot do the analysis as the data comes in? Can you look for the variance to rise above 5?  

[bwc1]

Thankyou for your reply

The application is as follows

I have a Gas water heater on which i change the water flow rate form say 4 to 6 l/min . The temperature of the water goes into oscilation as the water heater tries to adjust the temperature back to its set point . I have to know the time it takes for the temperature fluctuation to be less than 5K .

[TomRizzo]

To do that I would suggest to use a Start/Stop trigger that will trigger on when it starts to become unstable and turn it off when it is stable again.  The use the counter for time up to count the seconds the signal was up.

To decide what is unstable, the trigger should be set  to be outside the limits you think are best.

At the same time, like CJ suggested, you should store the data and use a post analysis product to analyse it.

[bwc1]

Ok will give it a go. Thankyou

[bwc1]

I already store the data for use in Excel. but i require dasylab to do the analysis. still not got round to trying the stop start trigger