Bar Chart - Fill in blank values, and make prediction slope greater than 0

[Yuval Eppel]

Hi everyone,

I am relatively new to Spotfire and would love for some help.

I am using holt-winters prediction on an aggergative bar chart - see example

(days in X axis, values in Y axis).

the value for each day is aggergative - meaning sum of all days before, plus current day.

therfore, I have 2 problems in my report:

1. there shouldn't be empty values (if no progress on certain day, should see the previous day value).

2. the prediction (and its confience range) can never be with negative slope - in the worse case, the progress is 0and the lines should be horizontal.

 

Any idea on how to implement these

Thanks! and health for everyone

[Shashank Gurnalkar]

1. To get the cumulative sum, you can use the expression like:

Sum([Your_value_column]) OVER (AllPrevious([Your_Date_column]))2. Keep the alpha, beta, and gamma (if you are using) parameters of Forecast Holt-Winters close to 1 so that the latest values will have more weightage. It looked like this at my end:

[Donald Johnson]

ep.yuval, did this work for you