Basic Expression Examples

About the Examples
The garden with the gray highlight is the control, it's used as a point of reference in each set of example comparisons. This is also the sample data used in the calculator when you click the Insert Sample Data button. Raw data used for the examples was purposely chosen to make the desired points. It is realistic given the vast differences in production that can be expected between gardens and gardeners in the real world. Lamps used in the examples are all HPS lamps.

Basic Expression Examples
Garden & Crop Production				Yield Expressions
Total Weight dried manicured grams (g)	Space canopy square feet (sq ft)	Illumination		Physical Resources		Energy Resources
Total Weight dried manicured grams (g)	Space canopy square feet (sq ft)	Light total lumens (L)	Energy watts (w)	Space (g/sq ft)	Light (g/kl)	Energy (g/w)	LPW L/w
284	8	49200	400	35.5	5.8	0.71	123
284	10	49200	400	28.4	5.8	0.71	123
284	12	49200	400	23.7	5.8	0.71	123
284	14	49200	400	20.3	5.8	0.71	123
When we compare yields for the four gardens above they differ only in the canopy space they use. Total weight and illumination are identical. Of the yield expressions shown, only Space hints that the first garden was operated more efficiently than the rest. The other expressions aren't showing that the first garden is actually yielding the same from fewer resources, their ratings don't give due credit for using less space more productively.

(2) These use identical space but have different illumination and total weight.				Space	Light	Energy	LPW
162	10	28000	250	16.2	5.8	0.65	112
284	10	49200	400	28.4	5.8	0.71	123
502	10	87000	600	50.2	5.8	0.84	145
780	10	135000	1000	78.0	5.8	0.78	135
The total weight for each garden was purposely chosen to produce the same Light rating as the control garden. With the Light ratings identical it becomes easy to see how the Energy expression is biased towards lamps with a higher LPW rating. Notice how the 0.84 Energy rating (the highest) comes from the lamp with the highest LPW, and how the order of the Energy figures follows the order of the LPW figures not the order of the Space or Light expressions. And though the order comes close to matching the Space figures, we know by the absence of space in the Energy g/w formula that it's the total weight figures typical of larger lamps driving the Energy values, not the scaled weight found in the Space expressions.

(3) Same as above, but with different spaces.				Space	Light	Energy	LPW
162	5.70	28000	250	28.4	5.8	0.65	112
284	10.00	49200	400	28.4	5.8	0.71	123
502	17.65	87000	600	28.4	5.8	0.84	145
780	27.50	135000	1000	28.4	5.8	0.78	135
The canopy space for each garden was purposely chosen to produce the same Space expression ratings as the control garden. Notice how the identical Light & Space ratings suggest that each garden's physical resources, regardless of their scale, were operated with the same degree of efficiency, but the order of the Energy expressions are still commensurate with the lamp's LPW. Using Energy as a measure of productivity could lead one to believe that certain growers run their gardens more efficiently than others, when in fact it shows which lamps run more efficiently than others, and that the higher grams associated with larger lamps are more a matter of scale than skill. And when you think about it, why shouldn't the fourth garden have more total yield? And why should having almost 5 times more space and light as the first make it more efficient? It's not what you got that counts for efficiency, but how well you use it! The first garden, though on a smaller scale, was operated just as efficiently as the others given the unique physical resources each had to work with. Energy resources, on the other hand, speaks more for the efficiency ratings of lamps than it does for their efficient use.