Forum Discussion
Spotting Sequences
Hello,
I have the following problem.
Suppose I am interested in finding sequences in [Value] made of 1's. I want to write the starting index of a sequence next to each of its members (column [Starting_Index]). Here is an illustration (I have columns [Index] and [Value], and want to produce column [Starting Index]):
| Index | Value | Starting_Index |
| 1 | 0 | 0 |
| 2 | 1 | 2 |
| 3 | 1 | 2 |
| 4 | 1 | 2 |
| 5 | 0 | 0 |
| 6 | 0 | 0 |
| 7 | 1 | 7 |
| 8 | 1 | 7 |
I thought maybe I could use the Starting_Index column in its creation itself, but obviously that is not how it works.
Starting_Index = IF([Value]=0;0;IF(LOOKUPVALUE([Value];[Index];[Index]-1)<>[Value];[Index];LOOKUPVALUE([Starting_Index];[Index];[Index]-1)))
I would be very grateful if somebody could help me.
Thank you.
The approach I'd take would be to find the last smaller index value that's zero, then add one to it - try:
startingindex = var currentindex = max(Table1[index]) var currentvalue = max(Table1[value]) var lastzero = CALCULATE(max(Table1[index]),Table1[value]=0,Table1[index]<currentindex) return if(currentvalue=0,blank(),lastzero+1)
1 Reply
The approach I'd take would be to find the last smaller index value that's zero, then add one to it - try:
startingindex = var currentindex = max(Table1[index]) var currentvalue = max(Table1[value]) var lastzero = CALCULATE(max(Table1[index]),Table1[value]=0,Table1[index]<currentindex) return if(currentvalue=0,blank(),lastzero+1)