I have simple line charts which shows prices and unit costs as the expressions and date as the dimension.
Assuming the date range is between 1st Jan 2014 and 1st June 2014. The chart is over this period.
I want to show the minimum unit costs reached between the 1st Jan and the current date in the line chart.
On the 1st Jan 2014 all three values would be the same as there is only a single date point.
On 1st Feb 2014, the price and unit costs will be different depending upon the buy/sell over that period. The minimum unit cost would be the min(Unit Costs) over the period 1st Jan - 1st Feb.
On 1st Mar 2014. the minimum unit costs would be the min (unit cost) between 1st Jan and 1st Mar
The expressions I tried:
1. MIN(Unit_Cost) - This is of course the same as Unit_Cost as there is only one unit cost for each date point
2. MIN(TOTAL Unit_Cost) - This is the minimum Unit_Cost between 1st Jan and 1st Jun. Not quite the same.
How do I achieve the Minimum of Unit_Cost between start date and the current date?