Good Afternoon I am building a Water Quality field data sheet and I am hoping someone can help me out. Our water Quality crews go out and take up to 4 but not always 4 could be 3,2,or 1 measurements. After taking the measurements they perform a calculation to determine if the measurements are within 10% of each other. The calculation I have come up with is below. I am wondering how if there is a way to make it so the value returned is always positive. For example is the first measurement is 5.7 and the second is 6.2 the value returned is -8.403361344537814. I would like it to be returned as a positive number. I am also wondering if there is a way to control the number of decimal places that are returned.
(${secchi_depth} - ${secchi_depth_a}) div ((${secchi_depth} + ${secchi_depth_a}) div 2) *100
Thanks
Dan Senner
Solved! Go to Solution.
There doesn't seem to be support for an absolute value function, so I've gotten around that by taking the second power and then the square-root so that it is always positive. (sqrt(pow((YOUR_FORMULA),2))
To control the decimal places use round(sqrt(pow((YOUR_FORMULA),2)),3) -in this case it's rounding it to 3 decimal places.
This page should be a helpful reference:
There doesn't seem to be support for an absolute value function, so I've gotten around that by taking the second power and then the square-root so that it is always positive. (sqrt(pow((YOUR_FORMULA),2))
To control the decimal places use round(sqrt(pow((YOUR_FORMULA),2)),3) -in this case it's rounding it to 3 decimal places.
This page should be a helpful reference:
Hi Katherine, thank you for the above recommendation. When I tried to use this example round(sqrt(pow((YOUR_FORMULA),2)),3) I keep getting unbalanced brackets and I cannot seem to figure out what I am doing wrong. I put my formula in from above where you say to put it but no luck. Any additional help or guidance with this would be appreciated.
Thanks
Dan
I did mine with an if instead.
from a repeat of shots
if(sum(${ElevationChange1})>0, sum(${ElevationChange1}), sum(${ElevationChange1}) * -1)
then compare across passes
100* ((${TotalElevationChangePass1} - ${TotalElevationChangePass2}) div ${TotalElevationChangePass1})
Again the negative in a hidden field just to make it easier to read
if(${SumCalc} > 0, round(${SumCalc},1), round(${SumCalc}*-1,1))
Then I have a note
Pass 3 is needed with a relevant of ${SumCompare} > 10 " Pass 1 and Pass 2 are not within 10%"
Seems to be working so far.
Hope that helps.