I am using ArcGIS 10.3 basic desktop to interpolate GPS soil points and then create a lime prescription map. I can easily interpolate the points however when I use the field calculator to enter the target lime formula for the desired pHw level I get an error message of 99999 that says a field name was not found or there were unbalanced quotation marks. The formula was produced by a leading university and has been used in numerous types of software so I don't believe it is the problem.
Thanks
What does the formula look like?
Are you using python parser of VB parser?
VB parser. I am not familiar with python code.
^ the image doesn't seem to work. Just copy/paste the expression into your post.
phw[0,6.24] : ((6.5-(-0.6))2*1.5)
phw[6.24,max] : 0
This is for a ph target of 6.3
soil pH measured in water? (it has been a long time)
phw[0,6.24] : ((6.5-(-0.6))2*1.5) = (7.1)*2**1.5) = 14**1.5 ????
really? something is missing in the formula since the actual value of pH isn't a variable anywhere. Can you go to the original reference and put the formula in without any substitution of terms. Or at least provide a reference (ie USDA, Brady et al or any soils text)
Try this one
the image isnt coming through on the iThingy and what you typed is not a formula, since there are no variables
right now, you take 6.5...subtract -0.6 from it...I presume multiply by 2 raised to the power of 2... that is a number. Just copy and paste that number down the column and you are done. or ... write out the formula that shows where the variables are...I am wildly guessing that it is in the -0.6 term but you have the source
Isn't that the same? I don't see the difference.
Since these are all constants, not variables from your table, you may as well just type in the number. Also, you do not have enough mathematical operators in the first part of the equation.
(6.5 minus -0.6) ______ 2 times 0.5
I think this may a job for ArcObjects
I'm not sure where you're getting your formula, but I've been looking for something similar online. It appears that this calculation is more complicated than a simple pH of the soil, as it varies due to soil type, soil buffering ability, relative neutralizing value of the lime applied, exchangeable acidity, residual lime credit, and various other complicated chemical factors. If you could give us a citation or some other reference, maybe we could help you find the calculation you need.
Les membres connectés peuvent publier, suivre les mises à jour, et plus encore. Nouveau ici ? Inscrivez-vous gratuitement.
Find useful guides, FAQs, and documents to help you navigate and make the most of Esri Community.
