Formula is not giving correct value
1 What is the expected behavior?
Value returned and set to variable chill should be 10.5
2 What is happening/not happening?
Something wrong with calculations
Any suggestions what I am missing in the algorithm?
what is the expected value of windchill? have you already compared the formula to whatever the source for it is to confirm the expression itself is correct?
Here is what I am using for formula: The new formula for winds in mph and Fahrenheit temperatures is:
Wind chill temperature = 35.74 + 0.6215T - 35.75V (**0.16) + 0.4275TV(**0.16)
In the formula, V is in the wind speed in statute miles per hour, and T is the temperature in degrees Fahrenheit.
Note: In the formula, ** means the following term is an exponent (i.e. 10**(0.5 ) means 10 to the 0.5 power, or the square root of V), - means to subtract, + means to add. A letter next to a number means to multiply that quantity represented by the letter by the number. The standard rules of algebra apply.
The result should be 10.5 F
i am not checking the formula for you … you dont want me checking it … too late on a friday night 
if you are sure of the expression already, could it be a operator precedence issue? may be try grouping them to set the precedence and check if that changes anything?
Make the wind and temperature variables decimal instead of dynamic and don’t read the _string options, read those that are numeric, you really want numbers. Unfortunatelly a lot of times string + string gives a string, even if they contain numbers. For instance ‘1’ + ‘0’ will give you ‘10’.
Thanks @ady624 and @bangali. I was actually missing a variable in my expression. Did change whe wind speed and temp to decimal too. Palm to the face!
If anyone wants to use what I have started
Is there a way to incorporate 2 restrictions into a single line for this.
If temperature is <= 50
And
If wind speed is >= 3
Then windchill = round((35.74 + 0.6215 * { $weather.conditions.current_observation.temp_f }- 35.75 * power($weather.conditions.current_observation.wind_mph ,.16)+ 0.4275 * { $weather.conditions.current_observation.temp_f " F"}*power($weather.conditions.current_observation.wind_mph ,.16)),1)
The calculation portion is correct but I don’t want it to set the windchill var if the conditions are not met. Would prefer an expression to define the windchill variable
You can use ternary operators:
(something == true ? wind *100 : 0)
If something is true you get wind*100, else you get 0. Then you can combine that further in your expression
glad you got it figured out.
so everything that was dynamic, still works by leaving it as dynamic?
thanks.
Trying to use ternary statement. But this is not working? What am I doing wrong?
decimal( $weather.conditions.current.observation.wind_mph)<=3?(decimal($weather.conditions.current_observation.temp_f " F")>=50)? ‘Windchill calculated’:‘windchill not calculated’
I know temp is suppose to be less than 50. But right now temps are all above and just trying to get it to process correctly then I will correct it
(decimal($weather.conditions.current.observation.wind_mph) <=3 && decimal($weather.conditions.current_observation.temp_f) >= 50 ? 'Windchill calculated' : 'windchill not calculated')
Didn’t seem to work correctly. Ended up doing this and seems to work right now.
If(decimal($weather.conditions.current_observation.temp_f)<50.0,if(decimal($weather.conditions.current_observation.wind_mph)>3.0,round((35.74 + 0.6215 * { $weather.conditions.current_observation.temp_f }- 35.75 * power($weather.conditions.current_observation.wind_mph ,.16)+ 0.4275 * { $weather.conditions.current_observation.temp_f }*power($weather.conditions.current_observation.wind_mph ,.16)),1) ,“NA”),“NA”)